Installations Flashcards
When constructing a walk-in freezer box, where is the vapour barrier installed?
a) under the floor slab
b) inside, on the coldest side
c) outside, on the warmest side
d) around any penetration sleeves
c)
Which of the following would be the best place to mount a wall thermostat?
a) kitchen
b) bathroom
c) exterior wall
d) near return air grille
d)
Condensate piping must be properly trapped to prevent?
a) ice formation
b) condensate running off evaporator coil
c) condensate overflowing the drain pain
d) excessive air noise in the piping
d)
Fresh air ducts used to route outdoor air to interior spaces, connect to the
a) vent piping
b) combustion air duct
c) supply side of duct system
d) return side of duct system
d)
The external equalizer connection to the suction line, should be located
a) next to the txv bulb
b) 6-8” upstream sensing bulb
c) 6-8” downstream sensing bulb
d) none of above
c)
For every 12k btuh of cooling, in open drive compressor air conditioning, the heat rejection is roughly
a) 12k btuh or 1.0 times net ref effect
b) 9k btuh or 0.75 times net ref effect
c) 15k btuh or 1.25 times net ref effect
c)
To protect a load, safety devices are often wired in
a) parallel
b) series
c) upstream
d) downstream
b)
Disadvantage of a mercury bulb switch?
a) unreliable
b) must be level
c) tend to brun contacts
d) tend to chatter
b)
Thermostat is properly calibrated when
a) set point and control point are equal
b) room temp is comfortable
c) there is no dead band
d) control point and thermometer reading are equal
a)
What minimum height must a refrigeration pipe be that crosses an area that affords a passageway?
a) 9ft
b) 6ft
c) 8.5ft
d) 7.5ft
d)
When installing a display freezer, how would you level the unit?
a) level to high point
b) not bother
c) grind floor so floor is level under unit
d) combination of shimming and grinding
a)
A fan in a display case is used for what purpose?
a) assist in condenser air circ
b) assist in maintaining air patterns
c) keep flies away
d) blow warm store air away
b)
ON an ammonia system for a rec centre the refrigeration lines maybe painted
a) suction light green and discharge red
b) suction red discharge green
a)
Once the plastic pipe for a secondary refrigeration or coolant have been laid and before they are back filled they must be
a) stretched
b) shrunk to fit
c) pressure tested
d) painted with a corrosion resistant finish
a)
What do you put on the top of the sleepers in an arena install?
a) pipe chairs
b) floor coolant piping
c) sideboards
d) sleeping spectators
a)
Spacing between sleepers or chairs in an arena floor is a usual minimum of
a) 3ft
b) 2 yards
c) 10ft
d) 6”
a)
How would you hoist an electric motor?
a) half hitches around shaft
b) rope woven through feet
c) lifting eye screwed in top
d) chain
c)
The sleepers installed in a rink floor are used to
a) support headers
b) support insulation
c) support concrete
d) support chairs for the refrigerant piping
d)
A hanger supported by 2 rods and from 2 separate roof support members is a
a) pivot type hanger
b) point ot point hanger
c) trapeze hanger
d) a 2 point clevis hanger
c)
Before slab for rink surface is poured the secondary ref piping is
a) x-rayed for cracks
b) pressure tested
c) re glued
d) stretched
d)
Length of the liquid line will usually
a) increase SH absorbed by the ref
b) increase SC due to TD between ambient air and ref leaving condenser
b)
What shall be used between back of flare and the nut?
a) nothing
b) lubricant
c) gasket
d) pipe sealing compound
b)
What type of rigid harness to lift an electric motor?
a) wrap around synthetic web sling
b) eyebolt and shackle
c) cable and U bolt
d) bridal sling
b)
When making 90deg bends in tubing where is the measurement between bends taken?
a) centre of bend
b) back of bend
c) end of bend
a)
How do you secure pipes to a steal beam?
a) beam clamp
b) riser clamp
c) inverted clevis clamp
d) a steel two hole clip
a)
What would you install in piping supply between 2 chilled water coils?
a) drip leg
b) union
c) bucket trap
d) PRV
b)
Where is the king valve located?
outlet of receiver
An instrument used to check alignment of two shafts connected with a coupling?
a) vernier caliper
b) inside caliper
c) hermaphrodite caliper
d) dial indicator
d)
The vapour barrier on a walk-in cooler, placed on the inside of the building is
a) not required
b) placed between insulation and interior of the box
c) placed on both sides of the insulation
d) placed on warm side on insulation
d)
Types of refrigeration and air conditioning tubing:
K - ______duty ( _____ wall)
L - ______ wall thickness
M - ______ duty (____ wall)
Type __ is most common in this trade
K - heavy duty (thicker wall)
L - Regular wall thickness
M - Light duty (thin wall)
Type L is most common
Which Refrigeration piping is the most crucial to install correctly?
Suction line
Suction line design and installation:
Common goal limit suction line to __F equivalent pressure drop
2F
Suction line design and installation:
- Return ___ back to the compressor under all load conditions
- Prevent oil from draining from active and inactive _________
- Prevent liquid refrigerant from draining back to the _________ during the off cycle
- Prevent unnecessary _____ gains and the line sweating
- oil
- evaporator
- compressor
- heat gains
Ensure trap is installed at the base of all suction line risers over __ft (good up to 25ft of rise)
8ft
Suction line design and installation:
- Use double suction risers if system can reduce capacity down to ___% of full load
- Insure high compression ratios are _______
- Pitch horizontal runs 1/2” down every ___ft in direction of flow
- Use _____ at the top of coil when pump down control is not used
- 50%
- avoided
- 10ft
- loops
Suction line design and installation:
Ensure ___” of suction line within the conditioned space before exiting
18”
Hot gas line design and installation:
Common goals limit hot gas line to __F equivalent pressure drop
2F
Trap at base of all hot gas risers over 8ft (good up to ___ft)
25ft
If vertical velocity is less than 1000fpm then a double ______ should be installed
riser
Hot gas design and installation:
- Use double hot gas risers if system capacity drops to ___% of full load
- Ensure a max gas velocity of _____fpm is not exceeded
- pitch all horizontal runs 1/2” every 10ft in direction of _____
- 50%
- 4000fpm
- flow
Liquid line design and installation:
Common goal limit liquid line to __F equivalent pressure drop
2F
Risers that have an eight foot vertical rise or less do not need to have an ___ ____ at the bottom of the riser
oil trap
- If the rise of the discharge or suction riser is greater than eight feet then a ____ should be installed at the bottom of the rise
- The reason for this is so that oil will not accumulate at the heads of the compressor during the ____cycle
- trap
- off
Purpose of a pump down system?
prevent liquid refrigerant from migrating back to the compressor
Horizontal refrigerant lines shall slope how much per 10ft?
1/2” per 10ft
Drain line slope is how much?
1/4” per foot
Refrigerant piping of less than 7/8 must be supported every
a) 12ft
b) 10ft
c) 8ft
d) 6ft
D
What must be checked before craning equipment on the roof?
Read manual and confirm phase/voltage
Sensing bulb installation on lines larger than 7/8?
4 or 8 o clock
Sensing bulb installation on lines smaller than 7/8?
12 o clock
Where should the sensing bulb never be installed?
6 o clock
