Review Questions for Grade 4 Refrigeration

Front

How to check a thermocouple?

Back

Open Circuit: about 25 to 30 mV

Closed Circuit: about 15 mV

Closed circuit means it is connected to a load

Remember: Closed circuit is about half of open circuit

Front

Calculate Net Stack Temperature

Back

Subtract the temperature of air entering the burner from the temperature inside the flue.

Front

How to check Waterside Pressure Drop in a condenser or chiller?

Back

Pressure drop is the difference from the inlet to the outlet.

Use a single gauge.

This makes sure the measurement is consistent with the same instrument

Alternatively, change the piping arrangement by using valves to be able to read with just one sensor.

Front

Total head lift with 65 PSI net pressure on a pump

Back

150 ft

Front

How to calculate the percentage of outside air using 3 temperature sensors.

Back

Front

How to test an OFC

Back

Use jumper 1 & 2 to keep the heater on.

or

Do a Dry Run Test

Front

How are floor tubes attached to the header in an ice rink.

Back

Use double gear clamps

Front

15 kW Electric Heater is 208V Single phase.

What is the Current?

Back

Front

15 kW Electric Heater is 208V THREE phase.

What is the Current Flow?

Back

Front

How could you repair a leak at the stem of a suction service valve on a refrigeration system?

Back

Tighten the packing gland and recheck for leaks.