Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
25 Cards in this Set
- Front
- Back
|
Recovery machines using water as the condensing medium would generally use the A. Cooling tower water B. Municipal water supply C. Condensate water D. Ice water |
B. Municipal water supply |
|
|
Frost would be best removed from a sight glass by A. Reversing the cycle B. Chip the ice off C. Spraying with alcohol D. Turn the water supply off |
C. Spraying with alcohol |
|
|
Recovery cylinders are color coded A. Yellow with grey tops B. Gray with the yellow tops C. Yellow with white tops D. Purple |
B. Gray with yellow tops |
|
|
Which refrigerant is CFC and has been used with low pressure appliances A. R-11 B. R-12 C. R-22 D. R-500 |
A. R-11 |
|
|
Type 3 certification as classified by EPA is for A. Small appliances B. High and very high pressure appliances C. Low pressure appliances D. None of the above |
C. Low pressure appliances |
|
|
The maximum pressure that should be applied to a low pressure chiller when leak checking with controlled nitrogen is A. 3 psig B. 10 psig C. 20 psig D. 30 psig |
B. 10 psig |
|
|
The short term replacement refrigerant for R-11 chillers is A. R-22 B. R-123 C. R-500 D. Nitrogen |
B. R-123 |
|
|
Water tube leaks in a low pressure chiller are usually found with A. Water puddles B. Frosted coils C. A hydrostatic tube test D. Leak detector |
C. A hydrostatic tube test |
|
|
The required evacuation level for recovering refrigerant from a low pressure appliance with a recovery machine manufactured before November 15, 1990 is A. 0 psig B. 4" hg C. 10" hg D. 25" hg |
D. 25" hg |
|
|
The required evacuation level for recovering refrigerant from a low pressure appliance with a recovery machine manufactured after November 15, 1993 is A. 10" hg B. 25 mm hg absolute C. 29" hg D. B and C above |
B. 25 mm hg absolute |
|
|
A low pressure chiller generally has the ruptured disk set at A. 3 psig B. 8 psig C. 10 psig D. 15 psig |
D. 15 psig |
|
|
To prevent freezing of the water coils of a low pressure chiller, it is recommended that A. When charging, begin with the vapor phase B. Circulate water through the chiller C. Do not inject liquid during charging until saturation temperature is above 32 degrees D. All of the above |
D. All of the above |
|
|
A low pressure chiller providing comfort cooling that has an annual leak rate of ______% of the total charge, must be repaired A. 15 B. 20 C. 35 D. 50 |
A. 15 |
|
|
R-134a is classified as a _______ under ASHRAE 34 Standard safety group A. A1 B. A2 C. B1 D. B2 |
A. A1 |
|
|
R-123 is classified as a _______ under ASHRAE 34 Standard safety group A. A1 B. A2 C. B1 D. B2 |
C. B1 |
|
|
Under ASHRAE Standard 15, what refrigerant requires equipment room sensors A. R-12 B. R-500 C. R-123 D. R-134a |
C. R-123 |
|
|
Under ASHRAE Standard 15, the following refrigerants require equipment room oxygen deprivation sensors A. R-11 B. R-12 C. R-134a D. All of the above |
D. All of the above |
|
|
Low pressure chillers require purge units because A. They operate below atmospheric pressure B. They draw non-condensable through gaskets and seals C. A and B above D. They don't require purge units |
C. A and B above |
|
|
The rupture disk of a low pressure chiller is connected to the A. High side B. Low side C. Compressor D. Purge valve |
B. Low side |
|
|
The purge unit draws from the A. Top of the condenser B. Section of the compressor C. Evaporator D. Rupture disk |
A. Top of the condenser |
|
|
Before a low pressure appliance is dismantled and salvaged A. The refrigerant must be recovered B. File recovery forms C. Reclaim the refrigerant D. Vent the refrigerant |
A. The refrigerant must be recovered |
|
|
Machine room safety standards have been established by A. ARI-7000 B. ARI-740 C. ASHRAE 34 D. ASHRAE 15 |
D. ASHRAE 15 |
|
|
Refrigerant vapor is charge into a low pressure chiller initially to prevent A. Safety shut down B. Water freeze up cause by system vacuum C. Quicker D. Never charge vapor into a chiller |
B. Water freeze up caused by system vacuum |
|
|
If excessive nitrogen pressure is exerted within a low pressure chiller, what component would fail first A. Evaporator coil B. Ruptured disk C. Compressor seals D. Cooling tower |
B. Rupture disk |
|
|
R-11 and R-123 refrigerants are A. Oxygen depleting B. Heavier than air C. Are class 1 and class 2 substances as defined by SPA D. All the above |
D. All the above |
