CR-39 Part 1 Questions With Complete Solutions
What is the minimum required size of a condensate drain pipe?
3/4 in.
A refrigeration compressor and all its associated controls and
accessories are to be installed. A pressure relief valve shall be
connected to which port on the compressor.
discharge service valve
What is the purpose of a metering device?
Prevents high pressure
What is the max distance that a fixture requiring hot water may
be from the source?
50 ft
What is the difference between a medium and high efficiency
boiler?
High efficiency boiler has an extra heat exchange
, In a hermetically sealed system, the oil in the crankcase is tested
and found to be acidic. What could be the cause or source of
this?
winding insulation failure
A motor is protected with a NTC (Negative temperature
coefficient) Thermistor. What happens when the motor
temperature goes down (decreases)?
The resistance (ohms) goes up.
What is the purpose of a bleed-off device in a cooling tower?
to keep the evaporating water system clean
What maximum nominal size soft drawn copper tubing may be
used for refrigerant lines?
2 in.
What device preheats the interior of a thermostat and causes the
contacts to open before the temperature reaches its proper set
point?
anticipator
What is the minimum required size of a condensate drain pipe?
3/4 in.
A refrigeration compressor and all its associated controls and
accessories are to be installed. A pressure relief valve shall be
connected to which port on the compressor.
discharge service valve
What is the purpose of a metering device?
Prevents high pressure
What is the max distance that a fixture requiring hot water may
be from the source?
50 ft
What is the difference between a medium and high efficiency
boiler?
High efficiency boiler has an extra heat exchange
, In a hermetically sealed system, the oil in the crankcase is tested
and found to be acidic. What could be the cause or source of
this?
winding insulation failure
A motor is protected with a NTC (Negative temperature
coefficient) Thermistor. What happens when the motor
temperature goes down (decreases)?
The resistance (ohms) goes up.
What is the purpose of a bleed-off device in a cooling tower?
to keep the evaporating water system clean
What maximum nominal size soft drawn copper tubing may be
used for refrigerant lines?
2 in.
What device preheats the interior of a thermostat and causes the
contacts to open before the temperature reaches its proper set
point?
anticipator
