Res Furn Commisioning Flashcards
1
Q
Where are Flow Switches located and what size of pipe should they be installed in?
A
In the supply line of a water boiler.
Install into 1 inch pipe, paddle needs to be free moving
2
Q
Define the term : Head
A
a pressure expressed in terms of height of a water column in feet
3
Q
Which of these 2 piston pumps can be OFFSET from the top of the well?
- Deep Well Piston
- Shallow Well Piston
A
- Shallow Well Piston
4
Q
What type of air does a aerating pilot burner use?
A
Only secondary air.
5
Q
What is the importance of the connection diagram?
A
It shows where wires go and the colour of the wires.
6
Q
Which one of the following items would indicat that you are looking at a hot water boiler and not a steam boiler?
- Makeup Water Line
- Backflow Preventer
- Pressure Operating Control
- Pressure Reducing Valve
A
- Pressure Reducing Valve
7
Q
Where are Averaging sensors located and what can they be used for?
A
Long capillary tudes located across the coil face: can be used in:
- High Temperature Control
- Coil Freeze Protection
- Low Temperature Limits
8
Q
What is the recommended output range for the open-circuit test on a thermocoupler?
A
17 to 32 millivolts (mV)
9
Q
What would you use to measure the quantity of electron flow?
A) voltmeter
B) ohmmeter
C) ammeter
D) electromotive force meter
A
C) ammeter
10
Q
What is the most important factor in replacing a combination Fan/Limit Control?
A
The length of the sensing element
11
Q
Draw the schematic diagram symbol for a Thermopile.
A
12
Q
What is the main purpose of a limit switch?
A
To shut down the gas supply, should the furnace gets to hot.
13
Q
The designation L1 (HOT) on a ladder diagram means what ?
A
J
Hot or black wire.
14
Q
In a 12 volt furnance is the Fan Circuit connected to the Ignition Burner Circuit?
A
No
15
Q
What is most common methods of measuring for a gas pipe length?
A
16
Q
Draw the schematic diagram symbol for a Closed Switch.
A
17
Q
What is required to in determining you have the right pump selected to do the job?
A
Todetermining you have the right pump selected to do the job,
you must determine :
- Vertical Lift from water to pump
- Plus Friction Loss to pump from water
- Vertical Lift from pump to point of water use
- Plus Friction Loss from pump toi point of use
- Desired Pressure at the point of use
18
Q
What can a Flame Rectification system do that a Flame Conductivity System can not?
A
(FR) can distinguish between a flame and short circuit, a (FC) can not.
19
Q
How much gas is allowed to vent and in what period of time?
A
- Propane - 1 cubric foot per hour
- Methane 2.5 cubric feet per hour
20
Q
Draw the schematic diagram symbol for a Door Switch.
A
21
Q
What is the list of operations for an Interrupted Pilot Ignition System?
A
- The main burner and pilot are both off till call for heat
- Once call for heat, ignition system lites pilot
- Igniton system then proves pilot is on and then lights main burner
- Igniton system then proves mian burner is on, then shuts off pilot
22
Q
With a pilot flame, what does a noisy, lifting, blowing flame mean?
A
- High gas pressure
- Excessive amounts of primary air
23
Q
Which of the following hot water boilers can be used to directly heat domestice water :
- Cast iron sectional
- Steel fire tube
- Cast iron condensing
- Copper water tube
A
- Copper water tube
24
Q
What diagram that would show you the most information about sequence of operation?
A
Flow chart
25
What is the Primary Component of a private water system?
The Pump
26
How do you discharge a capacitor?
with wires, connect it to a load (light bulb) to use up th electricity.
27
Are Close Nipples permitted for use on a natural gas system?
NO, There has to be a unthreaded section in the middle of the nipple.
28
What is a Dual-Rod pilot burner?
An electric spark ignitor with a flame sensor attached.
29
On a thermocouple, what is the Closed-CIrcuit Test?
Using a Millivolt meter, be disconnecting the leads. The meter is then attached to the connection to power unit and the adapter of the thermocouple.
30
Why should pump capacity be matched to well capacity?
To prevent aquifer problems from developing.
31
A stanard galvinized pressure tank contains 33.3% air and 66.6% water will release 20% of its water before the pump starts again.
This volume of water is called what?
Usable Water
32
The measurement of resistance is:
A) volts.
B) amps.
C) ohms.
D) watts.
C) ohms.
33
The 2 main types of water control switches are what?
2 main types of water control switches are :
1. Pressure Switches - found on systems using pressure tank.
2. Float or Drawdown Switches - found on systems using gravity or reservoir tanks.
34
What is the pressure output of a submersible pump impeller stage?
9psi per stage
35
The fan control in the furnace come on and off at what temperatures?
Turns the fan off between 90\*F and 100\*F and on between 120\*F and 140\*F.
36
What is the prupose of a CPU?
The cential processing unit (CPU) ia a microprocessor (computor) that controls the
1. operation of the appliance
2. sequences the igintion, firing of the main burner
4. monitors the safety controls
37
The creation of electricity is considered to be the?
1. Altering of one form of energy to another form of energy.
2. Creation of new energy.
3. Ability of mechanical equipment to change rotary motion to invisible energy.
4. Changing of AC to DC.
1. Altering of one from of energy to another form of energy.
38
What is the BTU valve of an EDR?
Steam (215\*F) 240 BTU/hr
Hot Water (160\*F) 150 BTU/hr
39
List the 3 acceltable methods to check for gas leaks.
1. Test dial
2. Commercial leak detector
3. electronic leak detector
40
What type on transformer is used in HVAC?
A step down, class 2, transformer
41
What degree of Flare is mainly used mainly for pipe trades?
45\* Flare
42
Why does a submersible pump required a check valve at its outlet?
To stop water from draining out of the drop pipe through the pump.
43
A 2" NPS has an actual inside diameter of 2.067" and a wall thickness of exactly 0.154". What is the exact outside diameter of the pipe?
0.067" + 0.154" + 0.154" = 2.375 or 2 3/8
Note that the pipe has 2 wall thicknesses.
44
Define interrupted pilot.
A pilot that is automatically ignited at the call for heat, ignites the main burner and is extinguished once the main burner is proven lit.
45
A low water cut-off senses the fluid level by use of a \_\_\_\_\_\_.
float or prode
46
Where can a Pressure switch be mounted?
Pressure switch be mounted :
1. On Pump
2. Piping between Pump and Tank
3. Tank
47
What is the difference between inside diameter and normal pipe size (NPS)?
INSIDE DIAMETER is the actual measement between the inside walls of the pipe across the exact center. NPS is an approximation of the inside diameter:
it is and industry standard used to identify varouse pipe sizes.
48
Draw the schematic diagram symbol for a Adjustable Fan Control Switch.
49
The measurement of electromotive force is:
A) volts.
B) amps.
C) ohms.
D) watts.
A) volts.
50
Draw the schematic diagram symbol for a Solenoid.
51
When a shut-off valve is placed on a tank tee for a residential installation, which side of the tank tee should it be placed on?
Outlet of tank tee
52
An electrical circuit must have:
1. Electromotive force and a load.
2. Electromotive force, a load and watts.
3. Electromotive force, a path and a load.
4. Electromotive force, a path and watts.
3. Electromotive force, a path and a load.
53
What is the main difference between an intemittent pilot gas valve and a direct ignition gas valve?
The direct ignition gas valve has no pilot connection.
54
The unit of measurement for energy that has been changed from electrical energy to mechanical energy is:
1. Unmeasurable.
2. Kilo ampere.
3. Mill volt.
4. Watts.
4. Watts.
55
Define standing pilot.
A pilot that burns constantly whether the main burner if fired or not.
56
On a ladder diagram for a furnance, what does BFANR stand for
Blower Fan Relay
57
To prevent possible issues, pressure controls must be installed how?
Level, for mercury to work correctly.
58
Draw the schematic diagram symbol for a Coil (Inducer).
59
Upon sensing an unsafe condition, the function of a limit control is to ?
Open a circuit
60
What is the secondary function of some pilots?
Activating a flame failure device (via thermocouple)
61
When looking at a symbol diagram of a transformer, how do you tell what side is the primary?
The side that has the most loops on it.
62
What elbow is NOT allowed in a gas line installation?
Street Elbow
63
The symbol for a normally closed switch that will open on temperature rise is what?
64
What is the factory setting for heating speed set to?
Medium Low
65
What two types of safety switches are available?
1. Automatice Reset
2. Manual Reset
66
What material is commonly used to construct sectional boilers?
1. copper
2. steel
3. stainless
4. cast iron
4. Cast Iron
67
Electromagnetism can be produced by:
A) the ability of electrical current flow to create a magnet from metals.
B) electrical current flow creating a magnetic field around a conductor.
C) the resistance of a conductor to current flowing through it.
D) elements that have chemically combined.
B) electrical current flow creating a magnetic field around a conductor.
68
How much higher should a limit switch be set than the fan temperature?
Should be at least 20\*F higher. If set to close the furnace may cycle OFF on the limit.
69
On a safety valve, the electromagnet attracts and holds the plunger it what possition to allow gas?
Open
70
The electric device that turns the pump on or off is called what?
Pressure Switch
71
If the wiring on a thermopile circuit exceeds 80 feet, a ______ system should be considered.
24-volts
72
73
How long have residential gas-fired appliances had electronic ignition systems?
The past 20 years.
74
Which of the following is a defination of net rating?
1. Amount of of heat energy available at the heat transfer units
2. amount of heat energy consumed by the boiler
3. amount of heat energy available at the boiler outlet
4. amount of heat lost to transmission losses.
1. Amount of of heat energy available at the heat transfer units
75
What is an Elastic Cell (Hydro Cell) and how does it work?
A Miniture Expansion Tank installed at the point of use.
76
On a thermocouple, what is the Open-CIrcuit Test?
Using a Millivolt meter, be diconnecting the leads. The meter is then attached to the internal core and the thermocouple sheath to.
77
One pound of pressure will lift a column of water _____ feet.
One pound of pressure will lift a column of water 2.31 feet.
78
What is the purpose of a safety relief valve?
To protect the boiler and system from excess pressure
79
in a series circuit, total resistance is:
A) the sum of all resistance in the circuit.
B) the difference between the largest and smallest resistance in the circuit.
C) less than the smallest resistance in the circuit.
D) the resistance of one resistor in the circuit.
A) the sum of all resistance in the circuit.
80
What are 2 atmospheric burner types?
1. Up-shot
2. in-shot burner
81
What is the minimum flame rod to ground electrode area that is immersed in the flame?
1:4
82
Define Pull- In Voltage as to thermopiles?
The minimum millivolt output of the thermopile required to energize and open the gas valve.
83
What types of impellers are used on centrifugal pumps?
1. Closed
2. Semi-closed
3. Open
84
What does a Flame Switch look like?
Flame Switch
85
What is a Single-Rod Pilot Burner?
An electric spark ignitor and flame sensor that are constructed as one piece. It ignites the pilot burner and also proves the flame is on.
86
List the purpose of having different flame patterns for a gas pilot.
Ignite the main burner under all conditions while providing heat from the main burner flame shall not come in direct contact with the thermocouple.
87
In a 24 volt furnance, what does the thermocouple power?
The electromagnet (power unit) in the gas valve. The rest of the gas train components are powered by a transformer.
88
What would you use to measure electromotive force?
A) voltmeter
B) ohmmeter
C) ammeter
D) electromotive force meter
A) voltmeter
89
When the wall thickness of a gas line gets thicker the inside diameter does what?
The inside diameter gets smaller
90
Amperage is known as the measurement of:
A) electrical currents flowing through a conductor.
B) the pressure it takes for electricity to flow through a conductor.
C) the resistance of a conductor to the flow of electricity through it.
D) the voltage flowing through the conductor.
A) electrical current flowing through a conductor.
91
What are some types of porable water sources?
Porable water sources are :
* Drilled Wells
* Driven or Jetted Wells
* Dug Wells
* Bored Wells
92
How does friction loss affect the use of a suction pump?
By reducing the amount of work done by atmosphere pressure.
Less volume moved by pump.
93
How are the controls on a wiring diagram shown?
Appliances OFF
94
When starting a pilot lit, how long does it take to heat up the thermocouple?
30-60 sec
95
What does an analysis of a thermocouple reading 30 mV open and 15 mV closed indicate?
Acceptable
96
What is the maximum theoretical lift of a centrifugal pump used as a suction pump?
Close to 34 feet
97
Why would the factory-installed jumper in a combination Fan/Limit control be removed?
To allow the control to use 2 different voltages.
98
What would you use to measure resistance?
A) volt meter
B) ohm meter C) ammeter D) resistance meter
B) ohm meter
99
What is special about the pipe thread for gas pipe threads for gas pipe?
It is a tapered thread. When thread compound/tape is applied will seal.
100
Define : psi
Pounds per Square Inch.
101
What does this abbreviation used ti describe steel pipe stand for?
Std
STD
Standard
102
What does NPT stand for?
National Pipe Thread
103
What do transformers found in furnaces do?
Take 120 volts AC and transform it into 24 volts AC through magnetic induction.
104
What will safeguard against poor threads, excessive die wear, cleaning debris build up and heat.?
Using a generous amounty of cutting oil.
105
Define Venturi Effect?
Based on the princple that when air, gas or liquid speeds up, the pressure will decrease. This low pressure in the burner will allow primary air to enter (throught the mixer) and mix with air prior to combustion.
106
What color of wires will be connected to a switch?
Black wire (hot)
107
What are the normal fan On-Fan off setting for a combination fan/high limit control?
130\*F - 90\*F
108
What temperature change can human bodies detect?
less than 1.5\*F
109
What is the difference between a Safety Hookup and a 100% Safety Hookup?
Safety hookup allows the pilot to remain on. 100% Safety hook the pilot will immediantly shut off.
110
On a gas valve what does TR mean?
This is the transformer connection.
111
What is the first step in the sequence of operation for any heating appliance with electronic ignition?
There is a call for heat at the thermostat.
112
Explain the function of a low pressure switch.
The low pressure switch monitors the refrigeration system for a loss of refrigerent charge and may also be helpful in stopping the evaporator (indoor) coil from freezing up due to a dirty filter or low over the coil.
113
When checking for gas leaks in gas line connections what is the approved method?
* methane gas leak detector
* Leak Detector Solution
114
Matter exists in one of several states because of:
A) atmospheric pressure acting on the matter.
B) the temperature to which the matter is heated.
C) the natural state in which the matter is found.
D) the combined state of solids and liquids.
B) the temperature to which the matter is heated.
115
Hows does the altitude of a pump installation affect pump selection and installation methods?
Higher elevations do not have as much atmospheric pressure.
116
What happend if you touch a Hot Surface Ignitor (HSI) with your finger?
The oils on your finger will cause the HSI to burn out where you touched it.
117
What is the issue with Spark ignitoers?
If the spark arcs to the burner instead of the ground surface, over time it will blow a hole throught the burner.
118
When the pump runs, pushing water into the system and compressing the air it will do what?
1. Prevent cycling of the pump
2. Ensures a smooth, even delivery of water
119
Draw the schematic diagram symbol for a Transformer.
120
What 3 mechanical items are in a gas valve in your furnace?
1. Houses the Power Unit. Which is apart of the flame sfeguard system
2. Regulator, Reduces gas line pressure to a lower operating pressure
3. Operator, when energized it allows gas to flow.
121
Draw the schematic diagram symbol for a Motor.
122
Limits with reset on them can be used to replace snap disc fan controls with summer fan switches? True or False
False
123
What is a Jet Pump capable of greater suction lift than a centrifugal pump?
Jet pumps are better at developing Negative Pressure than an centrifugal pumps.
124
What is the most common bi-metal temputre sensing device today?
The disc type
125
Define pictorial diagram.
It shows pictures or illustrations of the components typically in the position that they can be physically found in the equipment. This is also called a connection diagram.
126
How do you set up a Varaible type Anticipator?
They must be set to the same current draw (amps) of the control circuit to which the themostat is installed.
127
What is the solution for a fail turn-down test?
Relocate the pilot burner.
128
The measurement of electron flow is:
A) volts.
B) amps.
C) ohms.
D) watts.
B) amps.
129
What is required by a thermocouple open-circuit reading that exceeds 32mV?
The pilot flame must be reduced to achieve 32mV maximum.
130
What does an analysis of a thermocouple reading 26mV open and 6mV closed indicate?
Replace thermocouple
131
By adding more resistance in a circuit the current flow will:
1. Increase.
2. Decrease.
3. Be the same.
2. Decrease.
132
What is the purpose of a pressure relief valve?
Safety device to protect the system
It is a Adjustable Spring Loaded Valve
133
Is the switch always placed before the load on a ladder diagram? TRUE or FALSE
True
134
What does the Apprenticeship and Industry Training Act, allow you to do when serciving electrical components?
You are allowed to
- Service or changing controls, contactors or motors
- Repairing burnt or broken wires
- Making minor upgrades to existing heating, ventration and air conditioning systems.
135
The name applied to various circuits comes from:
A) the size of the resistors used.
B) the size of the circuit.
C) the size of the conductors used in the circuit.
D) the arrangement of conductors and components.
D) the arrangement of conductors and components.
136
By reducing the resistance in a circuit the current flow will:
1. Increase.
2. Decrease.
3. Be the same.
1. Increase.
137
Name two functions a thermopile can perform.
1. Operate the safety system (power unit).
2. Operate the main burner gas valve (operating gas valve)
138
Draw the schematic diagram symbol for a Fan Control Switch.
139
Which one of the following items would you find on a steam boiler?
1. Line Scoop
2. Diaphranm Tank
3. Flow Switch
4. Sight Glass
4. Sight Glass
140
What does this abbreviation used ti describe steel pipe stand for?
Sch
Sch
Schrdule
141
What are the reasons for setting the manifold pressure?
Setting the manifold pressure is a critical adjustment that is made not only to ensure that the appliance is not overfiring, but can be de-rate the appliance as well.
142
What is the recommended distance from the ends for bending a thermocouple?
The rule is one inch. In extreme cases, it can be bent 1/2" from the ends, but caution must be exercised.
143
When replacing a thermpile what must the installer do?
Ensure that the repacement has the same millivoltage as the damaged thermpile.
144
What is the secondary function of a pilot?
To activate the flame failure device which will turn off the gas to the appliance. This type of pilot is called a Proved Pilot.
145
What are helical screw pumps usually used for?
Pumping slurries and sludges
146
Atoms consist of:
A) an equal amount of protons and electrons.
B) a varying amount of protons and electrons.
C) always 3 or more electrons.
D) never more than 3 electrons.
A) an equal amount of protons and electrons.
147
Which test would be conducted with the circuit de-energized?
A) voltage
B) amperage
C) ohms
D) watts
C) ohms
148
What does this abbreviation used ti describe steel pipe stand for?
XXH
XXH
Double Extra Strong
149
What types of copper tubing can be used for gas lines?
Gas lines can be copper type G, K, L
150
Copper Tubing comes in different color codes, what color is the the M Type copper?
Red
M Type copper tubing CAN NOT be bent.
CAN NOT be used in gas lines.
151
What are the 2 most common types of anticipators?
1. Fixed (0nly in cooling systems)
2. Variable
152
What is the purpose of a union?
Allow for easy and quick assembly and disassembly of piping system.
153
With thermocouples, define Response Time.
Is the time it takes the thermocouple to cool suffiently to cuse the electromagnet on the power unit to de-energize and completely isolate the gas.
154
what should be checked on the blower motor assembly when performing the start up?
The blower assembly should be checked to confirm thet all the shipping blocks or brackets have been removed. The wheel inside the housing should be checked to make sure that it is running in the center of the housing and that it is secured properly to the shaft of the motor.
155
In a cooling unit, where is the high pressure switch located?
The switch is located in the tubing between the discharge side of the compressor and the condensing coil.
156
Where is a Foot Valves located and what is ther purpose?
Foot Valves are locatedd on the suction line.
It is a Vertical Check Valve
That keeps well pump primed
157
What is the maximum distance the supports can be apart on system 636 venting?
Five feet
158
What is recommended for cutting iron pipe ?
Using a pipe cutter. Turning slowly tighten the cutter 1/4 turn per revolution.
159
What part is missing on a post-aerating pilot and why?
The mixing tube, less suspitable to blockage by lint or dust.
160
What code covers the fabrication, installation and inspection of boilers?
ASME code
161
How many switches are inside of a combination fan/high limit control?
Two
162
What are Roll Out and Spill Swiches considered?
Temperature Sensing Safety Devices
163
What is the maximum allowable setting for a forced-air furnace?
250\*F
164
With a pilot flame, what does a hard, sharp flame mean?
- Characteristic of manufacturing, butane-ait and propane air flames.
- Orifice is to small.
- Too much gas pressure / volume.
165
When installing a flow switch using a long paddle, the shorter paddles are not used.
TRU or FALSE
FALSE
166
A 10" NPS pipe has an actual OD of 10.75" and an actual ID of 9.73". What grade of pipe is this and what is its wall thickness?
Grade = Sch. 60 or XS
WT = 10.75" - 9.73" = 1.02"/2 = 0.51"
167
What component in a furnance has a capacitor connected to it?
The blower motor
168
What does a pressure switch look like?
Basice Pressure Switch
169
Define : lpm
Liters Per Minute
170
The casted fitting we use are what class?
Class 150 (Standard)
171
What must all appliances have, ensuring that the appliance is installed where it is intended?
Rating Plate
172
What temperature does a Hot Surface Ignitor get to?
2600\*F (1427\*C) and lasts for approx. 17 seconds.
173
Define : Igph
Imperial Gallon per Hour
174
What is the importance of the ladder diagram?
It shows how the appliance works for troubleshooting.
175
In a 60 Hz system, how many times does it change direction (polarity)?
120 times a second.
176
What does an analysis of a thermocouple reading 16mV open and 16mV closed indicate?
Check power unit (also, a weak thermocouple; replace at the same time).
177
There is no contact between the water and the tank when the _______ type of pressure tank is used.
There is no contact between the water and the tank when the BLADDER TYPE of pressure tank is used.
178
What device can be installed to protect a hot water boiler from a low water level?
1. Limit Control
2. Thermostat
3. Probe Type Cut-Off
4. Safety Relief Valve
3. Probe Type Cut-Off
179
What are 2 types of diagrams?
1. Pictorial or Connection
2. Schematic or Ladder
180
What does the shedule number of a pipe designate?
The schedule number of a pipe designates the pressure / stress ratio X 1000
181
A sail switch can be used to monitor:
* Air Movement On / Off
* Ensure the correct volume of air moving
182
Where are Fast Response Elements located?
In the space that is being measured.
All tubing that is not in the area being measured MUST be insulated.
183
Define expanding pilot.
A pilot that constantly burns at a low turndown, but is automatically increases at the call for heat for proper ignition.
184
Which of the following could be classied as a high-mass boiler?
1. Copper tube boiler
2. Steel water tube boiler
3. Copper tube boiler for domestic water supply
4. Cast iron sectional boiler
4. Cast iron sectional boiler
185
How do you depict a component that has multiple functions on a ladder diagram?
With dasded lines that encircle the multiple electrilcal schematic symbols.
186
On a series circuit with two components, you measured 120 volts of AC power and then measured 1 component with a resistance of 3 ohms and the second one had a resistance of 2 ohms. What would the current draw be?
1. 0.041 amps
2. 0.041 volts
3. 24 amps
4. 24 volts
4. 24 amps
187
How does a pump work?
As the impleter rotates a NEGATIVE pressure is creatted at the inlet.
Which allows atmospheric pressure to force water into the suction line.
As the pump turns a POSITIVE pressure is created at the end of the implers, there for the outlet of the pump
188
What is the maximum operating temperature and pressure of a low-temperature hot water boiler?
low-temperature hot water boiler :
maximum operating temperature 120\*C (250\*F)
maximum pressure convential cast iron 207kPa (30psi)
189
What is the most common contact used in mechanical themostats?
Mercury
190
What is the step to a furnace call for heat flow chart?
1. Pilot on
2. Call for heat
3. Burners ignite
4. Fan comes on
5. System stays running until call for heat ends
6. Thermostat reaches ending call for heat
7. Burner shuts down fan keeps runnning
8. Fan shuts down ending call for heat
191
What type of meter is used to determine electron flow or current?
A) voltmeter
B) ohmmeter
C) wattmeter
D) ammeter
D) ammeter
192
What does the electrical output of a thermoelectric device depend on?
The amount of heat applied to the thermocouple and the difference in temperature between the hot and cold junctions.
193
Name the 2 common capacitors used in HVAC systems?
1. run capacitor ( furnace )
2. start capacitor ( Air condition compressor pumps )
194
What is the purpose of a Ball Check Leak-Limiting device?
To restrict (limit) the volume of gas escaping from the regulator vent in the event of a diaphragm rupture.
195
Define Flame Ionization.
Heat from a flame causes the molecules between the electrodes to collide with each other so forcibly that some of the electrons are knocked out of the atom; producing ions.
196
An ammeter is connected to a circuit, but the circuit's fuse keeps burning out. What is the problem?
A) the meter is connected to the circuit in series.
B) the meter is connected to the circuit in parallel.
C) the meter is connected to the load in parallel.
D) the meter is connected to the load in series.
C) the meter is connected to the load in parallel.
197
On a wiring diagram how do you illustraight Hot and Neutral wires?
Hot is (L1) or black
Neutral is L(2) or white
Ground is green
198
List 2 types of safety controls?
1. High Limit Switch
2. Therocouple (Themopile)
199
List the six (6) Components of a Private Water supply.
Components of a Private Water supply.
1. Electric motorized pumping unit
2. Pressure tank
3. Air volume control
4. Pressure switch
5. Relief valve
6. Foot valve
200
Draw the schematic diagram symbol for a Ground.
201
Name the type of electrical current generated by a thermoelectric device?
direct current (DC)
202
Draw the schematic diagram symbol for a node with connection.
203
What is the theropile test called that is similar to the drop-out test performed on themocouples?
pull-in voltage test
204
What is the approximate percent of carbon in the used to produce the following products?
- Steel Pipes
- Files
- Cast Iron
- Sheet Metal
Steel Pipes = 0.1% to 0.2% Carbon
Files = 1.5% Carbon
Cast Iron = 1.8% to 4.8%
Sheet Metal = 0.1% to 0.2% Carbon
205
What type of curve is on a centrifugal type fans in a furnace?
Forward curve
206
What device compensates for the normal expansion and contraction of the water in a hot water boiler?
1. Diaphragm Tank
2. Flow Switch
3. Operating Control
4. Line Scoop
Diaphragm Tank1.
207
A thermopile is a number of thermocouplers connected in \_\_\_\_\_\_\_\_\_.
series
208
What does this abbreviation used ti describe steel pipe stand for?
XXS
XXS
Double Extra Strong
209
What copper tubing type can be used for gas lines?
Types G, K and L
210
What 2 terminals close when there is a call for heat?
The R (transformer) and W (heat)
211
A Fast Response Element is normally wound into a coil?
TRUE or FALSE
TRUE
212
How many millivolts does a thermopile produce?
750mV
213
What amps does a themostat need to be set to?
The same as the gas vlve, which is usaully 0.2 amp
214
Draw the schematic diagram symbol for a Humidity Activated Control Switch.
215
Define Foot Valve
Is a type of vertical lift check valve on the suction end of the piping in the well.
It ensures that the pump will be primed.
216
Define : Friction Pressure
Friction Pressure is :
A measurable reduction in pressure, caused by the force that resists motion between two bodies in contact.
What rubbing the inner walls of the pipe and the turbulence of the water as it travels down the pipe cause friction and therefore friction loss.
217
How does the diameter of a well affect pumping capacity?
By limiting the size of pump you can use.
218
How is a pump able to lift water from a well?
By creating a partial vacuum in the pumping chamber.
219
You notice a reduction in the amount of water from the well and a scale formation is present on the plumbing fixtures.
What is the problem and how would you correct it.
A reduction in the amount of water available from the well and mineral building up on plumbing would be caused by mineral scaloe building (encrustration) on a perforated well casing.
This problem is corrected by cleaning the pump and acidizng of the well by a licensed well driller.
220
Is a schematic diagram drawn in an energized state (on) or de-energized state (off) ?
Always drawn i a de-energized state (off).
221
Define the term : Pressure
A measurement expressed in unit of weight per area; for example, pounds per square inch.
222
A circuit with an open switch is called:
1. Short circuit.
2. Closed circuit.
3. Open circuit.
4. Loaded circuit.
3. Open circuit.
223
What should the heat anticipator setting match?
The amperage draw of the 24-volt circuit.
224
What test is conducted when a meter is connected to the circuit in series with the power on?
A) amperage
B) voltage
C) resistance
D) wattage
A) amperage
225
Lis the 4 most common arrangements for the contacts of a relay.
1. SPST - NO single pole throw normally open contacts
2. SPST - NC single pole double throw normally closed contacts
3. SPDT - single pole double throw
4. DPDT - double pole double throw
226
On a series circuit, you measured a current flow of 2 amps and found that it had a resistance reading of 6 ohms. How many watts of power are being transformed?
1. 12 volts
2. 12 watts
3. 24 volts
4. 24 watts
4. 24 watts
227
Which one of the following items would you find on a hot water boiler?
1. Pressure Operating Control
2. Sight Glass
3. Expansion Tank
4. Equalizer line
3. Expansion Tank
228
Why are some jet pumps called Convertible Jet Pumps?
The jet assembly can be removed from the pump and placed in a well.
229
What is the difference between a shallow well and a deep well?
Depth to the pumping level of the well.
230
What problems can occur in a conventional boiler if the flue gases are cooled to their dew point?
Draft hood spillage or damage caused by corrosive condesate.
231
What does ASPT stand for?
American Standard Pipe Thread
232
When a clip-on ammeter is used, what should be done when the amperage is too low to obtain a reading?
A) get a smaller clip-on ammeter
B) take the voltage and resistance, then use Ohm's law
C) clip the ammeter around two wires and divide the reading by two
D) use a 10-wrap multiplier and divide the reading by 10
D) use a 10-wrap multiplier and divide the reading by 10
233
The rating plate on a furnace has information about; A. heat exchanger warranty B. the output of the furnace C. maintenance
B. the output of the furnace.
234
Desribe Ladder Diagram.
Symbols are used and they don't show component location.
They are designed more for sequence of operation.
Ladder diagrams are always read left to right.
Controls are always on the left side.
Loads are always on the right side.
235
A circuit that has three different paths for electrons to follow is called:
1. Three path circuit
2. Series circuit.
3. Short circuit.
4. Parallel circuit.
4. Parallel circuit.
236
Define intermittent pilot.
A pilot that is automatically ignited at the call for heat, ignites the main burner and remains on throughout the burner cycle.
237
What pipe has a maximum pressure of 200 psi?
XS / Sch 80
238
On a pilot what does a yellow flame mean?
- Diry, lint are being burnt.
- The orifice is to large
- Flame requires more oxygen for complete combustion.
239
The pilot flame should cover the tip of the thermocouple by __ to \_\_.
3/8" to 1/2".
240
How many pressure sensing areas are there on an air pressure switch?
Two
241
How are low-temperature boilers usually rated?
Net Rate in BTU/hr or EDR
242
When making a gas line connection to a furnace, what material do you need?
Black Iron Pipe
Norminal Pipe Size (NPS)
Schedule 40
243
What is the most common problem associated with a pilot that produces an orange flame?
Dirt, dust and other impurities in the air used for combustion.
244
All gas regulators have 3 essential elements in common, what are they?
1. Restricting Element
2. Measuring Element
3. Loading Element
245
On a circuit, if you measure 24 volts with your volt meter and then measure 0.5 amperage draw on a component, how many watts of power is being converted?
1. 120 watts
2. 12 watts
3. 6 watts
4. 4.8 watts
2. 12 watts
246
What is the proper procedure of taking a piece of pipe and getting it ready for a gas line installation?
* Cut with a pipe cutter. No oil
* Use a reaming tool to re-bur the inside
* Cut threads with a treader and using oil
247
An installation that requires air to be replenished in the pressure tank requires an air volume control. The two most common tyoes of air volume control are What 2 types?
1. Diaphragm
2. Float Switch
248
Basic furnances have what type of operating electrical volt systems?
120 volt (AC) fans with 24 volt (AC) controls.
249
What is the purpose of an anticipator?
Anticipate the temperature in the room, shutting down the furnace just before the temperature reaches the setting on the ttermostat.
250
What are the 4 types of configurations for electronic ignition system?
1. intermittent pilot using spark
2. intermittent pilot using hot surface
3. direct ignition using spark
4. direct ignition using hot surface
251
Who will make sure that the furnace will be placed on its own 15amp breaker?
The electrian
252
Most LWCO (low water cut off) come with how many switches, and what are there functions?
There are 2 Switches :
1. Low Water
2. High Water
253
What is a dirt pocket designed to do and what is the minimal length?
It is designed to catch debris in the gas line prior to the gas entering the appliance.
Must be 3" in length and the same diameter as the gas line.
254
What is the difference between black iron pipe and galvanized pipe size?
Black iron pipe has seelac or varnish applied for protection.
Galvanized iron pipe has a zinc coating applied by hot dipping the black pipe to provide 2 oz per square foot of coating inside and outside.
255
Define : USgpm
United States gallons per minute
256
What is the purpose of oil when threading?
To lubricate the the treads when be cut. This reduces friction and heat.
257
Define Thermistor?
A small resistor (size of pencil lead) made from semi-conductor material (platinum). Resistance decreases (allow more electron flow), as the temperature increases. Micoprocessor in the thermostat measures the resistance and converts the reading to tempurature.
258
What does the term alloyed as applied to the manufacture of ferrous pipe mean?
Alloy are the other metals mixed with iron to produce special qualities in pipe.
259
Which pumps may produce enought pressure to damge a pressure system?
1. Centrifugal and Jet pumps used as suction pumps
2. Reciprocating and Submersible pumps
2. Reciprocating and Submersible pumps
260
Draw the schematic diagram symbol for a Fuse.
261
What can cause coil damage in a low-mass boiler?
Low or NO flow through the heater exchanger.
262
What does it mean when a digital meter flashes the display?
A) the meter battery is getting low.
B) the meter is connected to the circuit incorrectly.
C) the meter is been damaged and should be replaced.
D) the valve has exceeded the meter setting.
D) the valve has exceeded the meter setting.
263
Draw the schematic diagram symbol for a Pressure Switch.
264
Define : Flow Rate
A measurement expressed as a Volume per a Specific period of Time.
Eg. Gallons per minute
265
What pipe has a maximum pressure of 1000 psi ?
XXS
266
At what size for STANDARD PIPE does the wall thickness remain the same for increases in pipe size and what is the WT
Size = 12"
WT = 0.375"
267
Draw the schematic diagram symbol for a Heat Thermostat.
268
What is the recommended output range for the closed-circuit test on a thermocoupler?
8-17 millivolts (mV)
269
Name three bimetal temperature sensing devices.
1. strip type
2. spiral type
3. disc type
270
What device is used on the outlet of two-pipe jet jumps to allow the pump to produce the most water possible?
A flow control fitting or valve
271
What is the one benifit of using corrugated stainless tibing over black iron pipe?
It can be bent easily and routed around objects.
272
What type of power is used in a Flame Rod?
Direct Current (DC)
273
When is a well considered to be a deep well?
When the well's pumping level is deeper than 24 feet.
274
What are bushings used for?
To reduce the size of the pipe system.
275
All electrical circuits require which three things?
1. Load
2. Conductor
3. Power Source
276
Electrical pressure is measured in:
A) amperes.
B) Ohms.
C) current.
D) volts.
D) Volts
277
What device protects the boiler from excessive temperature?
1. Expansion Tank
2. Automatic Air Vents
3. Pressure Reducing Valve
4. Limit Control
4. Limit Control
278
What is the formulas for converting gas into Btuh?
converting gas into Btuh
279
What test is used on a thermopile system to test proper ignition of the main burners at a low pilot flame conditions?
an effective ignition test
280
What is the minimum number of switches a low water cut-off can have?
One
281
What should you be looking for when checking duct connections?
When checking duct connections, you should look for openings and gaps that might cause excessive leaking.
282
It is considered safe practice to inspect the electrical connections with the power turned on?
TRUE
FALSE
FALSE
283
What is the purpose of a thermacouple?
To produce 20-30 mV of power to energize an electromagnet in the power unit which keeps gas flowing to the pilot.
284
Electrons orbit the nucleus of the atom in pathways called:
1. Orbits.
2. Tracks.
3. Rings.
4. Shells.
4. shells
285
Define Schematic Diagram.
A diagram of something that uses symbols to represent components of equipment in a diagram.
286
Draw the schematic diagram symbol for a Thermocouple.
287
A standard galvanized pressure tank that has lost its air charge is said to be what?
Waterlogged
288
The voltage of a circuit is 24 volts and the resistance is 150 ohms. Using Ohm's law, what is the expected amperage?
A) 3600 amps
B) 16 amps
C) 6.25 amps
D) 0.16 amps
D) 0.16 amps
289
Which device separates air from the water leaving the boiler?
1. Manual Air Vent
2. Boiler Scoop
3. Cushion Tank
4. Pressure Reducing Valve
2. Boiler Scoop
290
In a parallel circuit, total resistance is:
A) the sum of all resistances in the circuit.
B) the difference between the largest and smallest resistances in the circuit.
C) less than the smallest resistance in the circuit.
D) the resistance of one resistor in the circuit.
C) less than the smallest resistance in the circuit.
291
Which meter is never connected to an energized circuit?
A) voltmeter
B) ammeter
C) wattmeter
D) ohmmeter
D) ohmmeter
292
When one electron bumps into another electron and this bumping continues throughout a conductor, this bumping action is called:
A) valance electrons.
B) coulomb.
C) electron flow.
D) resistance.
C) electron flow.
293
What does a Med-efficiency furnace High Limit Switch look like?
294
The Ohm's law triangle is used to:
A) allow an electrical motor to be connected to a squirrel cage fan.
B) develop a formula to solve for an unknown quantity in an electrical circuit.
C) solve for only the resistance of an electrical circuit.
D) create new energy.
B) develop a formula to solve for an unknown quantity in an electrical circuit.
295
What is an Anticipator?
It is a component that is wired in prior to the thermastat. It makes the thermostat believe the room is at the set temperature before it actually is.
296
What another term used to describe an aerated pilot?
Bunsen or linting
297
What classification could be used to describe a fire tube boiler?
1. copper tube
2. high mass
3. low mass
4. sectional
2. High Mass
298
How is an ammeter connected to a circuit when measuring currents?
A) in series with the circuit to be tested
B) in parallel with the circuit to be tested
C) in series/parallel with/to the circuit to be tested
D) in series and parallel to the circuit to be tested
A) in series with the circuit to be tested
299
When using electronic ignition, what is the process of proving the flame call?
Flame rectification
300
A voltmeter is correctly connected to a circuit, but the needle deflects below zero. What corrective action will you take?
A) replace the meter.
B) change the batteries in the meter.
C) choose a higher meter setting.
D) reverse the meter leads.
D) reverse the meter leads.
301
What does a basic electro-mechanical type relay look like?
basic electro-mechanical
302
What pipe has a maximum pressure of 150 psi ?
Std / Sch 40
303
A circuit has 120 volts and 15 amps of current. Using Ohm's law, what is the resistance of the circuit?
A) 80 ohms
B) 8 ohms
C) 0.8 ohms
D) 0.08 ohms
B) 8 ohms
304
What is the primary function of a pilot?
To effectively ignite the burner.
305
How many multiple speed seting can you get on a direct drive fan motor?
Its common to hav eup to 5 speed settings.
306
Define proved pilot.
A pilot flame that is supervised by a flame failure device (thermocouple).
307
What does this abbreviation used ti describe steel pipe stand for?
XH
XH
Extra Heavy
308
What flame volour must a pilot flame have?
Blue, to ensure there is NO soot or carbon reisdue that will cause failures in the igniting of the burner or safety controls.
309
Snap discs can be either manual or automatic reset.
TRUE or FALSE
TRUE
310
A pump works by creating a _______ pressure on the inlet of the pump, which allows atmospheric pressure to force water into the suction line.
A pump works by creating a NEGATIVE pressure on the inlet of the pump, which allows atmospheric pressure to force water into the suction line.
311
What is the correct ratio of water to air in a standard pressure tank?
1/3 air
2/3 water
312
What is the purpose of a gas pressure switch?
To turn off the gas in the event of low or high gas pressure.
313
Where are Hot Surface ignitors(HSI) used?
Usually with direct ignition systems. This alleviates the need for a pilot burner.
314
How do you set up an Fixed Anticipantor?
The installer DOES NOT set it. The anticipator comes from the manufacturer preset.
315
The two types of hook-ups used for safety devices are _______ hookup and \_\_\_\_\_\_\_\_hookup.
safe hookup and 100% safe hookup.
316
Materials that have less than 3 valence electrons are called :
A) conductors.
B) semi-conductors.
C) insulators.
D) semi-insulators.
A) conductors.
317
When determining the voltage of a DC circuit, where does the red meter lead connect?
A) to the negative polarity of the circuit
B) to the positive polarity of the circuit
C) it does not matter where the leads go
D) to the common wire
B) to the positive polarity of the circuit
318
What is the minimum clearance required for the service side of an appliance?
24 inches
319
On a gas valve what does TH mean?
This is the thermostat connection
320
With a pilot flame, what does a Blue waving flame mean?
- Excessive draft in pilot location
- Recirculating products of combustion
321
All circuits have a power source, a path for electron flow,
a control device and a power consumer called a/an:
A) appliance.
B) fuse.
C) switch.
D) load.
D) load.
322
What is the symbol for a capacitor?
capacitor
323
What activates the pressure switch?
The pressure switch is activated when the IDM (inducer motor) starts turning and creates enough pressure, it will force the diagram to move toward the microswitch, closing it.
324
What are the 2 main principles in flame rod detection systems?
1. Flame rectifaction
2. Flame conductivity
325
What is the material called that is used to seperste the 2 plates in a capacitor?
dielectric
326
What would the resistance be in a 24 volt circuit that had 6 amps of current running through it?
1. 0.25 ohms
2. 4 ohms
3. 4 amperes
4. 12 amperes
2. 4 ohms
327
On a heat only thermostat, the contacts will\_\_\_\_\_\_\_.
close on the temperature decrease.
328
Can you clean a Flame Rod?
Yes, very carefully with scotch pads or 000 steel wool.
329
What is the difference between Interrupted and Intermittent Pilot Ignition Systems?
With Intermittent Pilot Ignition Systems the pilot stays on throught the call for heat.
330
What is the name of the temperature sense in a electronic thermostat?
Themistor
331
Constituents of the atom include:
A) atoms, molecules and elements.
B) magnets,shells and nucleus
C) electrons, protons and neutrons.
D) volts, amps and resistance.
C) electrons, protons and neutrons.
332
With Flame Rectification what are the purposes of the electrodes?
One is the flame rod and the other is the chassis ground (burner ground).
333
If you are unsure of the voltage in a circuit, what range should you select for the meter?
A) a range lower than that expected
B) a range higher than that expected
C) a range the same as that expected
D) the range selected is not of concern
B) a range higher than that expected
334
What is the fixed element that controls the amount of gas that a pilot will burn?
the orifice.
335
What is the purpose of a Oriface in the burner manifold?
To regulate the gas flow to the burner.
336
With a pilot flame, what does a small Blue flame mean?
- Low gas pressure
- Clogged orifice
- Clogged pilot line filter
337
An air volume control is used on a bladder-type pressure tank.
TRUE or FALSE
FALSE
338
What is the maximum temperature setting a ECO ( energy cut off) will be set?
Same as that of the temperature and pressure relief. (usually 200\*F to 210\*F)
339
How much does a cubric pound of Water?
62.4 pounds
340
With an Intermittent ignition, what happens with the pilot burner?
The pilot is extinguished automatically each time the call for heat ends.
341
What is the main difference between a normal Bulb Element and a Fast Response Element?
The fast response elemnt is 7 times larger than the normal element.
342
Why have flame conductivity systems not been used for providing the flame?
The system will not distinguish between a flame and a short to ground.
343
Draw the schematic diagram symbol for a High Limit Control Switch.
344
Which direction must the venting on the furnace slope
Upwards and away from the furnace.
345
When do the blower speeds have to be changed?
The blower speed have to be changed if the temperature rise is to low or to high
346
When taking the resistance of a component, why is it necessary to isolate the component from the circuit?
A) to ensure that there is no other current pathway
B) to ensure that the voltage does not harm the meter
C) to ensure that the component is de-energized
D) to ensure that the meter can be connected to the the circuit
A) to ensure that there is no other current pathway
347
What is a Flame Rectication?
Flame rectication is an AC electrical circuit that sends a very small current from the furnace electronic board-up to the flame rod. When the flame is established, the flame acts as a path or conductor, which allows the current to flow across the flame from the flame rod to ground (burner), thus completing the circuit.
348
What does this abbreviation used ti describe steel pipe stand for?
XS
XS
Extra Strong
349
What does a pressure switch controll?
The water pump.
* Supplies power when low limit is reached
* Disconnects power when high limit is reached
350
What is the method of connecting copper tubing in a gas line?
Flare Fitting
351
Name the adjustable component that control the amount of gas the pilot will burn.
A needle valve or, on larger appliances, a pilot regulator.
352
Where is the CPU located?
The electronic control board contains the CPU in most modern day HVAC equipment.
353
How many adjustment setting switches are there on a combination fan/high limit control?
Three
1. Fan On
2. Fan Off
3. High Limit Setting
354
To convert feet of head to psi, multiply by \_\_\_\_\_\_\_\_.
convert feet of head to psi, multiply by 0.433
1 psi will u-tube water 27.6" ( 2.31')
355
356
List 5 operating controls in a furnace?
1. thermastat
2. fan control
3. transformer
4. gas valve
5. motor
357
What are the 5 steps for selecting and sizing of a private water system?
5 steps for selecting and sizing of a private water system :
1. Discharge pressure
2. Suction Pressure
3. Pump Capacity
4. Two-Pump System
5. Type of Pump
358
Current that flows first in one direction and then reverses itself is called:
A) direct current.
B) reversing current.
C) alternating current.
C) alternating current.
359
What another term used to describe a non-aerated pilot?
Non-Bunsen or non-linting
360
What does a AIr Shutter do?
It regulates the amount of primary air that enters the burner.
361
List the 5 parts to of a relay.
1. coil
2. core
3. return spring
4. armature
5. contacts
362
How may Drawdown in a well affect an Aquifer?
Drawdown can allow the aquifer to start releasing sand.
363
What term is used to describe electrical pressure?
A) amperage
B) resistance
C) wattage
D) voltage
D) voltage
364
The resistance to current flow of an electrical circuit is expressed in units of resistance called:
A) amperes
B) Ohms.
C) current.
D) volts.
B) Ohms.
365
Name the 3 main designs of pilot burners.
1. Non-aerated
2. Aerated
3. Post-aerated (incinerating/target)
366
What is a Roll-Out Switch?
Roll-Out Switch
367
What is the issue with Silicon Carbide Ignitors?
Over time, the igniter will develop an oxide coating on it that will impede the current flowproving flame.
368
What mandatory device is required on a coil type boiler over 400 000 BTU/hr :
1. Flow Switch
2. Indoor-outdoor Control
3. Thermostat
4. Flow Control Valver
1. Flow Switch
369
List 2 things that will happen if the wire size to the pump is too small to adequately meet the power requirements?
1. The expected life of the electric motor will be reduced.
2. Electrical Energy will be lost in the form of heat in the feeder circuit.
370
Define Rectifier.
Is a device for converting AC current to DC current.
371
Draw the schematice diagram syblol for a node.
372
What unit is used to describe the resistance of a circuit?
A) volts
B) amps
C) ohms
D) watts
C) ohms
373
How is temperture rise calculated?
The difference of return air temperature and the supply air temperature.
374
Which of the following is a defination of boiler input?
The amount of energy consumed by the boiler.
375
What does an air pressure switch use to sense pressure?
Diaphragm
376
Where can an Aquastat be used?
* Boiler High Limit
* Cooling Tower Low Limit
377
Draw the schematic diagram symbol for a Open Switch.
378
What is the normal high limit setting for a combination Fan/High limit control?
180\*F - 250\*F
379
What are 2 types of blower fans?
1. Belt drive
2. Direct drive
380
A typical circuit board on any furnace will have only one voltage.
TRUE
FALSE
FALSE
381
What is the only thing that a home owner should touch on a furnance system?
The themostat
382
How is the voltmeter connected to a circuit to attain the correct voltage?
A) in series with the power on
B) in series with the power off
C) in parallel with the power on
D) in parallel with the power off
C) in parallel with the power on
383
List 2 reasons why a well must be protected from surface water.
1. Surface water will contaminate a well
2. Surface water could puddle and freeze, damaging piping and other components
384
What device is used to maintain pressure within a system?
1. Safety Relief Valve
2. Expansion Tank
3. Automatic Vent
4. Pressure Reducing Valve
4. Pressure Reducing Valve
385
What is the electromagnetic device used as a load in a safety circuit usually called?
Power unit
386
A post-aerating pilot utilizes primary air and secondary air, but has no ____ \_\_\_\_ .
mixing tube
387
388
Why are centrifugal pump suction lines installed with positive grade from the well to the pump inlet?
For better air elimation when priming.
389
What is the most commen motor found a furnace?
Squirrel cage induction motors.
390
List 4 types of pressure tanks.
Types of pressure tanks :
1. Standard Galvanized Tank
2. Floating Disc
3. Diaphragm
4. Bladder
391
What condition may cause cavitation for a centrifugal pump?
Pump is working at maximum lift capacity
392
The power unit and the thermocouple together make up a system called \_\_\_\_\_\_\_.
flame safe guard
393
When using Ohm's law, what does E/R represent?
A) Voltage
B) amperage
C) resistance
D) wattage
B) amperage
394
Compounds are made up of:
A) elements that have chemically combined.
B) chemicals that have been mixed together.
C) elements with an electrical charge.
D) chemicals that have been non-chemically combined
A) elements that have chemically combined.
395
What is the purpose of a continuity test?
A) to determine the resistance of a circuit
B) to determine whether there is a continuous circuit
C) to determine the amperage of the circuit
D) to determine the voltage of circuit
B) to determine whether there is a continuous circuit
396
A circuit that has only one path for electrons to follow is called:
1. Short circuit.
2. Series circuit.
3. Parallel circuit.
4. Electron circuit.
2. Series circuit.
397
The strength of an electromagnet is dependent on three factors:
A) the shape of the iron core, the size of the wires wrapped around it and the size of the iron core.
B) length of the conductors, size of the iron core and type of conductors.
C) type of core material, number of turns made around the core and amperage applied to conductors.
D) type of core material. number of turns made around the core and voltage applied to conductors.
C) type of core material, number of turns made around the core and amperage applied to conductors.
398
Where must a pilot light be installed as per Code?
1. mounted where it can be seen and safey lit.
2. Must be properly positioned with respect to the main burners.
3. Not be exposed to falling scal and dirt during noraml operation.
4. The main burner should NOT touch pilot.
5. Pilot must have an ample supply of air that is free of products of combustion
6. Pilot will NOT recieve the full force of the burner ignition or extinction.
7. Should NOT be affected by drafts.
8. Must lit burner under all conditions.
9. The pilot will secured to a place relavive to the main burner.
10. Pilot flame can Not touch any material or the burner
