EPA Type III Certification Test #1

A typical setting for the high-pressure cut-out control on a recovery unit used for evacuating refrigerant from a low-pressure chiller is

• 2 psig

• 5 psig

• 10 psig

• 15 psig

A charged low pressure refrigeration system can be efficiently leak-checked by

• adding compressed air since it will be removed from the system by the purging unit.

• operating the purge system.

• adding HCFC-22.

• raising system pressure by heating with circulated hot water or heating blankets.

The existence of air in a low pressure system causes

• low head pressure.

• low suction pressure.

• high head pressure.

• high liquid level.

Which safety precaution should be adhered to for low pressure systems?

• Do not siphon refrigerant by mouth.

• Avoid spilling liquid refrigerant on your skin.

• Use gloves and safety goggles when working with liquid refrigerant.

• All of the above.

Refrigerant-11 (R-11) at 14.7 psia, will boil at about

• 60.3 F

• 74.5 F

• 79.5 F

• 80.2 F

When there is excessive moisture collecting in the purge unit of a low pressure refrigeration system, this indicates that

• the system with contaminated refrigerant.

• the condenser or chiller barrel tubes are leaking.

• the purge unit is not operating properly.

• the purge unit needs adjustment.

ASHRAE Standard 15-1994 requires equipment room refrigerant sensors for what safety group classification?

• A1

• B2

• A2

• All refrigerant safety groups.

When recharging a refrigeration system with R-11, what vapor pressure is necessary in the shells before charging with liquid? 

• 21.1 inch Hg vacuum

• 19.7 inch Hg vacuum

• 18.1 inch Hg vacuum

• 16.9 inch Hg vacuum

After reaching the required recovery vacuum on a chiller, you should

• Immediately disconnect the recycling or recovery equipment and open the system for service.

• wait for at least a few minutes to see if the system pressure rises, indicating there is still refrigerant in liquid form or in the oil.

• Immediately break the vacuum with nitrogen and open the system for service.

• Immediately pressurize the system with nitrogen and perform a leak check.

A hydrostatic tube test kit is used to

• blow all water from the tubes.

• remove any water from the machine.

• vent refrigerant.

• determine if a tube leaks.