Will an AC compressor work without oil?
Your AC compressor requires lubrication for proper functioning and a long life because anytime you have metal parts rotating or sliding they will fail quickly if they aren’t properly lubricated.
Why is it necessary that the crankcase heater heats the compressor?
Crankcase heaters were designed as an addition to existing compressor models. They use a simple electrical circuit to create heat within the crankcase when the compressor is not in use. The heat keeps the refrigerant from condensing and prevents refrigerant from migrating through the seals into the oil.
What happens if non Condensables are left in the system?
A system with non-condensables will have poor cooling and high humidity and will appear to be operating normally, making identification of this problem difficult.
Is the crankcase heater on when compressor is on?
A crankcase heater is an electrical component in a compressor in an air-conditioning system, heat pump system, or chiller system. The crankcase heater is normally on all the time, even when the unit is not running, though temperature sensors and set points may turn it off when not needed.
How would you remove moisture from refrigerant in a system?
Moisture can be removed from a refrigeration system by applying a vacuum. POEs hold moisture more tightly than mineral oil. But in the case of R-134a, the refrigerant effectively competes with the ester lubricant in partitioning the water (i.e., the water moves from the lubricant to the refrigerant).
When should refrigerant be removed from the condenser?
Refrigerant should be removed from the condenser outlet if the condenser is below the receiver. In a building that has an air-cooled condenser on the roof and an evaporator on the first floor, recovery should begin from the liquid line entering the evaporator.
What can happen when using a large vacuum pump to evacuate a system?
When evacuating a system, the use of a large vacuum pump could: A) cause trapped oil to freeze. When using recovery and recycling equipment manufactured BEFORE November 15, 1993, technicians must evacuate a unit that has a normal charge of 10 pounds of CFC-500 to ___________ before disposing of the system.
When a system is in deep vacuum you should never?
When a system is in deep vacuum; 1. Never add refrigerant to the system.
When would a reciprocating compressor be damaged if energized?
TYPE II
| Question | Answer |
|---|---|
| 24. When could a reciprocating compressor be damaged if energized, | A. When the discharge service valve is closed. |
| 25. It is best practice to use dry nitrogen to break the vacuum when dehydrating by the triple evacuation method, However, | D. requires a pressure regulator |
When recovering from a system with a refrigerant leak recover to a level of?
EPA 608 Type 2 Flash Cards
| Question | Answer |
|---|---|
| 18. High pressure appliances can be evacuated to atmospheric pressure (O psig) when? | There is a leak |
| 19. When dehydrating a system it should be evacuated to a level of? | 500 microns |
| 20. When recovering from a system with a refrigerant leak, recover to a level of? | 0 psig |
What state is the refrigerant in when it enters the compressor?
saturated vapor
In what state should a system be to measure a final system vacuum?
In what state should a system be to measure a final system vacuum? With the gas ballast open. With the vacuum pump operating.
Which refrigerant has lowest global warming potential?
R-717
Why should refrigerant vapors or mist in high concentrations not be inhaled?
Refrigerant vapors or mist in high concentrations should not be inhaled since: They may cause heart irregularities or unconsciousness. A refrigerant cylinder that has a grey body and a yellow top indicates the cylinder is designed to hold: Recovered refrigerant.