B1-7 Heating Boiler And Heating Systems Controls; Auxiliary Building Systems Flashcards
With a bleed type thermostat, a vane is moved away from or toward a nozzle as the temperature in the controlled space changes. This movement:
A) opens the air dampers
B) adjusts the output pressure of the controller
C) starts and stops the compressor
D) closes the air dampers
E) increases tension on the torque spring
B) adjusts the output pressure of the controller
Pressure controllers can be divided into two classes, namely, high pressure and low pressure controllers.
A) true
B) false
A) true
Heating system on off control thermostats are equipped with: A) a low temperature switch B) a high temperature switch C) a forward relay switch D) an open contact switch E) a small cooling fan
D) an open contact switch
A device used to position dampers and control valves is termed: A) a controller B) a relay C) a transformer D) a temperature controller E) an actuator
E) an actuator
One common range for electronic controllers is: A) 4-20 milliamps B) 4-20 millivolts C) 4-20 amps D) 0-10 milliamps E) 0-10 amps
A) 4-20 milliamps
A sensor consisting of a layer of hygroscopic salt deposited between two electrodes can be used to measure: A) flow B) level C) temperature D) humidity E) pressure
D) humidity
A thermistor is typically enclosed in a very small case and provides quick response to temperature changes.
A) true
B) false
A) true
An E/P transducer is a device that is used to: A) generate a set point signal B) filter an electronic signal C) produce an off or on signal D) convert an electrical signal E) amplify an electronic signal
D) convert an electrical signal
In general, lamp efficiency is directly proportional to its: A) colour B) size C) amperage D) voltage E) wattage
E) wattage
An optimally designed lighting system will usually:
1) have good energy efficiency of the luminaires
2) have an adequate service life for the lamps
3) have low colour rendition numbers
4) provide satisfactory comfort and visibility
A) 1 and 2 only
B) 1,2,3 and 4
C) 1,2 and 4 only
D) 1,2 and 3 only
E) 2,3 and 4 only
C) 1,2 and 4 only
Occupancy sensors are: A) automatic switches B) semi automatic switches C) self regulating switches D) modulating switches E) none of the above
A) automatic switches
In lighting systems, the most effective means of controlling the level of illumination is to employ: A) on off switches B) dimmers C) occupancy sensors D) motion sensors E) photoelectric sensors
B) dimmers
Building codes limit the highest pressure permitted in plumbing systems to: A) 175 kPa B) 350 kPa C) 490 kPa D) 560 kPa E) 650 kPa
D) 560 kPa
When the maximum building demand for water is always less than the flow available, the:
A) constant pressure system with pneumatic tank can be used
B) down feed system can be used
C) tankless constant pressure system can be used
D) constant pressure system with suction tank can be used
E) gravity system can be used
C) tankless constant pressure system can be used
The 5 methods used to prevent back flow are: 1) air gap 2) pressure relief valve 3) double check valve 4) atmospheric vacuum breaker 5) venting 6) pressure vacuum breaker 7) atmospheric relief valve 8) reduced pressure principle device A) 1,2,3,4 and 5 only B) 2,4,5,6 and 8 only C) 1,3,4,6 and 8 only D) 2,3,4,5 and 7 only E) 1,3,5,6 and 8 only
C) 1,3,4,6 and 8 only
Automatic air vents on a hot water distribution system are usually installed at the: A) top of the hot water riser B) midpoint of the return piping C) top of the plumbing fixture D) top of the hot water tank E) top of the building
A) top of the hot water riser
The recommended minimum slope for a 76mm diameter, horizontal run of waste pipe is: A) 11mm/m B) 12mm/m C) 18mm/m D) 21mm/m E) 30mm/m
D) 21mm/m
The vertical pipe used to convey rainwater to the building storm drain is called a: A) stack B) drainage tile C) drain riser D) gutter E) leader
E) leader
The kind of pump usually used to lift the sewerage from the sump in a building is a submersible: A) injector B) vacuum pump C) gear pump D) centrifugal pump E) reciprocating pump
D) centrifugal pump
If a flush tank toilet is running continuously, the cause may be: 1) a leaking ball cock 2) a leaking float 3) incorrect water level adjustment 4) supply water pressure too high 5) an incorrectly bent float arm A) 1,2,3,4 and 5 B) 2,3,4 and 5 only C) 1,3,4 and 5 only D) 1,2 and 3 only E) 1,2,3 and 5 only
1,2,3 and 5 only
It is common practice to have a backup water supply for heating boilers that opens to supply city water into the boiler when a low level condition occurs.
A) true
B) false
A) true
A float operated mechanical feeder valve used to control secondary supply of feedwater into the heating boiler should:
A) not open until the level is well below the feed pump cut in level
B) be located above the water column
C) open just after the low water cutoff switch opens
D) open just before the low water cutoff switch opens
E) not be deemed a standby device
A) not open until the level is well below the feed pump cut in level
Two methods used to combat carbon dioxide corrosion in condensate systems include:
1) coating the piping with amines
2) adding oxygen scavenging chemicals
3) using a mechanical deaerator
4) using cast iron condensate return lines
5) adding neutralizing amines to the condensate
A) 2,4
B) 1,2
C) 1,5
D) 3,5
C) 1,5
Dissolved oxygen in condensate will:
A) cause pitting in a boiler
B) necessitate the installation of a deaerator
C) cause pitting in the return lines
D) not be removed using chemicals
E) cause grooving of the condensate lines
A) cause pitting in a boiler
In nearly all LP steam heating systems, the feedwater:
A) is mostly condensate
B) has a high makeup percentage
C) must be deaerated
D) requires daily close scrutiny of chemical consumption
E) requires preheating in an economizer
A) is mostly condensate
Modulating combustion control of a heating boiler is accomplished by:
A) opening or closing the forced draft damper
B) shutting down or lighting up the burner as pressure or temperature rises or falls
C) regulating the air flow to control combustion
D) changing the firing rate of the boiler
D) changing the firing rate of the boiler
A manual high low switch should be switched to high or auto:
A) as soon as the main flame has stabilized
B) when the boiler has been properly warmed up
C) during the boiler prepurge
D) prior to ignition of the main flame
E) when pressure is too low
B) when the boiler has been properly warmed up
Which of the following controls would you expect to find on a low pressure steam boiler? 1) operating pressure control 2) high limit temperature control 3) high limit pressure control 4) operating temperature control A) 3 and 4 only B) 1 and 3 only C) 1 and 4 only D) 1,2,3 and 4 E) 2 and 4 only
B) 1 and 3 only
A test lead or jumper wire is required when testing:
A) a low gas pressure fuel cutoff switch
B) a safety valve with test lever
C) high steam pressure limiting control
D) the low water fuel cutoff switch
E) a high gas pressure fuel cutoff device
C) high steam pressure limiting control
High limit temperature controls:
A) are required on steam boilers
B) are required under section II of the ASME code
C) shut off the fuel to a hot water boiler if the water temperature is too high
D) increase air flow to the boiler if temperature limits are exceeded
E) open a 3-way mixing valve to add cold water reducing the water temperature
C) shut off the fuel to a hot water boiler if the water temperature is too high
Flame rods:
A) should shut off the fuel within three seconds of flame failure
B) are very reliable and maintenance free
C) should be cleaned of deposits regularly
D) require frequent filing of electrical contacts to prevent corrosion build up and failure
E) should not be exposed to temps above 100*C
C) should be cleaned of deposits regularly
The maximum allowable temperature for the water in a hot water heating boiler is: A) 100*C B) 120*C C) 150*C D) 170*C E) 250*C
B) 120*C
A flame detector that senses visible light and uses cadmiumoxide and an anode wire is called a: A) rectifying photocell B) ultraviolet scanner C) infrared scanner D) cathode ray tube photocell E) vacuum tube photocell
A) rectifying photocell
When a pneumatic controller increases the control pressure on an increase in controlled condition, it is called: A) direct acting B) proportional C) on off D) reverse acting E) modulating
A) direct acting
The main disadvantage of a bleed type controller is that:
A) it requires a wide control range
B) its operation is noisy
C) it wastes a considerable amount of compressed air
D) it cannot be used for controlling humidity
E) it is not accurate for temperature control
C) it wastes a considerable amount of compressed air
A pneumatic control system:
A) is not used to control air flow for ventilation
B) is never used to control humidity
C) requires an intermittent air supply
D) uses a sensing element to change pressure in the control line
E) outputs to controlled devices activated by a 4-20 amp electric current
D) uses a sensing element to change pressure in the control line
The most common type of heating system damper operator is a: A) ramp B) slide C) pilot positioned D) piston E) bellows
D) piston
A transformer is an electrical device that is used to convert AC or DC voltage from one value to another
A) true
B) false
B) false
In a basic electrical control system for a heating system, the device that senses a drop in air temperature is called the: A) humidistat B) thermostat C) egulator D) final controlled device E) pneumatic temperature sensor
B) thermostat
A room thermostat should be mounted on an inside wall about: A) 0.5 m above the floor B) 0.75 m above the floor C) 1.0 m above the floor D) 1.25 m above the floor E) 1.5 m above the floor
E) 1.5 m above the floor
The output signal from an electronic controller:
A) converts pressure to temperature
B) may not be used to regulate relative humidity
C) is used as the input signal to a transmitter
D) is typically used to position an actuator
E) is used to generate a setpoint
D) is typically used to position an actuator
A sustained difference between the setpoint and the value of the controlled variable is called: A) integral action B) remote setpoint C) negative compensation D) deviation E) offset
E) offset
Resistance temperature devices can provide a relative linear resistance variation from: A) -40 to 250*C B) -40 to 120*C C) 40 to 100*C D) 0 to 100 *C E) -60 to 80*C
B) -40 to 120*C
Electronic output devices such as actuators can be divided into two action types, namely: A) on or off B) modulating and direct acting C) indirect and direct acting D) two position and modulating E) two position and on/off
D) two position and modulating
To prevent light loss due to the accumulation of dirt, luminaires must be cleaned no less than: A) twice a year B) once a year C) once every two years D) once every three years E) once every five years
D) once every three years
The disadvantages of an indirect lighting system are: 1) harsh shadows 2) less energy efficient 3) greater potential for veiling reflects 4) increased floor to ceiling height A) 1,2 and 3 only B) 1 and 2 only C) 2 and 4 only D) 3 and 4 only E) 2,3 and 4 only
C) 2 and 4 only
Luminaires can be classified into the following types:
A) incandescent, fluorescent and H.I.D.
B) general, local or supplementary, and combined general/local
C) manual, on/off, and automatic
D) fluorescent, incandescent and sodium vapour
E) recessed troffers, ceiling mounted wrap around, open reflectors and structural lighting
E) recessed troffers, ceiling mounted wrap around, open reflectors and structural lighting
In large buildings, approximately what percentage of the electrical load is lighting? A) 60% B) 65% C) 70% D) 75% E) 80%
A) 60%
Which of the following statements about non circulating hot water systems is true?
A) the system is used in large residential buildings
B) the system contains a differential fire recoil element
C) the system eliminates hot water stagnation
D) the system forces more water to be wasted before hot water is available in each fixture
E) the system has a return line
D) the system forces more water to be wasted before hot water is available in each fixture
In an indirect hot water heater, the water is heated using:
A) hot water or steam from the heating system
B) electric elements
C) gas or oil fired burners
D) natural circulation
E) radiant heaters
A) hot water or steam from the heating system
Building codes recommend that nowhere in a building's plumbing system shall the water pressure fall below: A) 65 kPa B) 175 kPa C) 350 kPa D) 490 kPa E) 560 kPa
B) 175 kPa
Most building regulations limit the length of a hot water pipe in a non circulating system to: A) 30.2 m B) 20.5 m C) 15.2 m D) 12.5 m E) 6.0 m
C) 15.2 m
The function of a water faucet is similar to a: A) gate valve B) flush valve C) stop and check valve D) butterfly valve E) globe valve
E) globe valve
Corrugations in outside aluminum sheet metal drainage conductors are required to:
A) increase flow speed of storm water
B) decrease potential for blockage
C) eliminate corrosion
D) allow water flow if there is scale buildup
E) permit expansion
E) permit expansion
When pipe carrying waste from a building makes a change of 90 degrees in the horizontal direction, the elbow(s) that may be used is/are: A) a 90* elbow B) one 30* elbow and one 60* elbow C) two 45* elbows D) one 15* elbow and one 75* elbow E) any of the above arrangements
C) two 45* elbows
The horizontal pipe that carries the building's waste from various fixtures should have a minimum flow rate of: A) 1.2 m/s B) 0.6 m/s C) 0.4 m/s D) 2 m/s E) 3.0 m/s
B) 0.6 m/s
