Red seal online 313a practice test with
questions and answers
What would be the minimum VA requirement for a 24v AC transformer powering 4
thermal electric expansion valves with a resistance of 150 across each heater? (15.4)
What would be the problem on a time initiated, temperature terminated defrost if the
defrost cycle runs full time during periods of light coil frosting? (Faulty defrost
thermostat)
If the pressure differential across the circulating pump is 21.65 psi, how many feet of
head is the pump capable of lifting? (50)
When testing a compressor motor winding with a megger, what reading would indicate a
good clean system? (infinity)
What is the minimum required sleeve size when installing a 2 in. pipe with 1 1/2
insulation through an 8 in. concrete block exterior wall? (6)
What is the probable cause of high suction pressure on a heat pump? (leaking four-way
valve)
How should a load be lifted with a wrap around sling when crushing of the load is a big
concern? (Place a spreader above and below the load)
Which 3 instruments are required to check the calibration of an enthalpy control on the
economizer of a rooftop air conditioning unit? (Thermometer, sling psychrometer, and
multimeter)
What is the indication of a plugged metering device? (high suction gas superheat)
What must be verified before replacing the electronic control board if the onboard
diagnostic fault is incorrect? (Verify power supply, all inputs and loads are properly
connected and true)
What amperage capacity should the supply wiring be rated for a refrigeration fixture
which has a 208v power supply and the following loads: 4 evap fan motors rated at 9w
each? (4)
questions and answers
What would be the minimum VA requirement for a 24v AC transformer powering 4
thermal electric expansion valves with a resistance of 150 across each heater? (15.4)
What would be the problem on a time initiated, temperature terminated defrost if the
defrost cycle runs full time during periods of light coil frosting? (Faulty defrost
thermostat)
If the pressure differential across the circulating pump is 21.65 psi, how many feet of
head is the pump capable of lifting? (50)
When testing a compressor motor winding with a megger, what reading would indicate a
good clean system? (infinity)
What is the minimum required sleeve size when installing a 2 in. pipe with 1 1/2
insulation through an 8 in. concrete block exterior wall? (6)
What is the probable cause of high suction pressure on a heat pump? (leaking four-way
valve)
How should a load be lifted with a wrap around sling when crushing of the load is a big
concern? (Place a spreader above and below the load)
Which 3 instruments are required to check the calibration of an enthalpy control on the
economizer of a rooftop air conditioning unit? (Thermometer, sling psychrometer, and
multimeter)
What is the indication of a plugged metering device? (high suction gas superheat)
What must be verified before replacing the electronic control board if the onboard
diagnostic fault is incorrect? (Verify power supply, all inputs and loads are properly
connected and true)
What amperage capacity should the supply wiring be rated for a refrigeration fixture
which has a 208v power supply and the following loads: 4 evap fan motors rated at 9w
each? (4)
