EPA Type 2 Flashcards
What conditions allow for a system to be opened and repaired without recovering the refrigerant to the required vacuum level
A system with a large leak and system pressure of atmospheric
High pressure appliances can be evacuated to atmospheric pressure when
Leaks make evacuation to the prescribed level unattainable
EPA regulations state that maintenance, service, or repair involving the removal of the following components is major repair
Compressor, condenser, evaporator, auxiliary heat exchanger coil
Refrigerant should be removed from the condenser outlet if the condenser is
Below the receiver
When EPA regulations change regarding refrigerant usage
Technician can lose their certification or be fined if violating updated regulations even if unaware of changes
If a refrigeration condensing unit is sittin idle in an ambient temperature of 86*F at a pressure of 93psig it must contain
R-12
A crankcase heater is often used to prevent refrigerant from migrating to the oil during periods of
Low ambient temperature
Recovering refrigerant from the discharge service valve if a compressor is known as
The pull method of recovery
What might be an indication of a loss of charge in a fixed orifice A/C system
Increased evaporator superheat
What is the smallest size leak which EPA regulations say must be repaired on an air cooled chiller servicing the A/C in an office building and containing a charge of 240lbs of r-22
3lbs per month
High pressure appliances containing 100lbs of an hcfc other than r-22. Recover and recycling equipment manufactured after Nov. 15, 93 must be evacuated to a level of
10” hg
An r22 evaporator operating at a pressure of 83psia and with a suction line leaving it at 52F is operating with __ if superheat
12 degrees
EPA regulations require that all commercial and industrial process refrigeration containing more than 50lbs of refrigerant must be repaired when the annual leak rate exceeds
35%
R22 unit containing 255lbs by weight of refrigerant charge is recovered down to 15” hg and after five minutes the pressure rises and levels off at 10” hg then
Recovery is complete
Which of the following refrigerants is an hcfc
R22
A systems compressor should never be __ when in a deep vacuum
Energized
When replacing the compressor on a 50 ton system which contains a receiver, the charge can be
Pumped into the receiver for storage during service
When brazing in refrigeration system accessories which use neoprene or rubber gaskets
Wrap a wet rag around the area to keep it cool
For the fastest recovery of a system which should be recovered first
Liquid refrigerant from the receiver
Unless plans are made to replace a system exceeding the max leak, repairs must be made in
30 days
Non condensables will cause
Higher discharge pressures
An overcharged system will operate
Less efficiently
Which refrigerant is considered high or very high pressure refrigerant
Hfc134a
What would be most thorough for leak testing
Mixture of trace r22 with nitrogen backed up to 300psig
When using nitrogen to pressurize a system for leak testing always make sure to use
A regulator on the nitrogen tank
What should one do to an empty A/C system after repairing a leak and before recharging it
Check the system for leaks
A refrigeration system which has a txv will likely be __if it has 2*F of sun cooling in the liquid line, just after the condenser
Undercharged
At which location is a low loss fitting on your manifold hose likely to prevent the most venting of refrigerant
At the king valve
The purpose of a vacuum pump is to
Remove air and moisture from a system before charging it with refrigerant
A/C system short cycling is normally caused by
The system being oversized for the home
Proper recovery techniques begin with the use of appropriate recovery equipment that has been certified by
EPA approved equipment testing organization
When dehydrating a system it should be evacuated to a level of
500 microns
Recovering r500 from an A/C system containing 12lbs of charge, the unit must be recovered down to a pressure of
10” hg
The purpose of a purge or pump out mode of a recovery machine is to
Help clear another refrigerant from the machine in order to avoid mixing refrigerants
What can help reduce the time necessary to recover the refrigerant from a unit (3things)
Shorter hoses, cool the recovery cylinder, run the unit to warm it
All refrigeration and HVAC systems are protected by a
Pressure relief valve
According to EPA regulations, the refrigerant in a system containing 12lbs of refrigerant and an inoperative compressor can
Legally be recovered using passive methods
How much refrigerant must leak out of a 2ton residential A/C system before EPA regulations require that the leak be fixed
Not required to be leak free
If pulling a system down to the EPA required recovery level cannot be accomplished because of system leaks
It must be recovered down to at least 0psig
What can be done with the refrigerant trace gas and nitrogen after the leak is found
Can be released to the atmosphere
A refrigerant sensor which will sound an alarm and automatically start a ventilation system in occupied equipment rooms falls under
ASHRAE standard 15
A new split system should be checked for leaks by
Pressurizing the system with r22 and an inert gas
When recovering from a system with a refrigerant leak, recover to a level of
0 psig
What happens to a refrigerant that is above the saturation temperature
It remains in a vapor state
When using a recovery system manufactured after Nov. 15, 93 on a system containing 100lbs of r502 must be evacuated to
10” hg
Industrial and process refrigeration units with a 50lb charge or more with an annual leak rate of __ or more must have leaks repaired
35%
Refrigerants cfc r12, hcfc r22 and hfc 134a are classified as
A1
A high pressure appliance containing 210lbs of refrigerant recovery and recycling equipment manufactured before Nov. 15, 93 must be evacuated to a level of
4” hg
