Type 3 Flashcards
What problem can occur with an open compressor after sitting for several months?
The shaft seal can leak.
How should you begin charging appliances with liquid-type heat exchangers to prevent them from freezing?
With vapor.
What requirement must be met in order for a mechanical room containing R-717 to not be required to have a leak sensor?
The mechanical ventilation must run continually.
Where do leaks often occur that allow in air and moisture?
Gaskets and fittings.
What can be done to help perform a leak test?
Use heater blankets and hot water.
What does ASHRAE 15 require for mechanical rooms?
A refrigerant sensor that will sound an alarm and automatically start a ventilation system.
What problem can occur if nitrogen is used for a leak test with a pressure exceeding 10 PSIG?
It can damage the rupture disk.
When leak testing a water box, what should be done before placing the leak detector probe through the drain valve?
Be sure the water has been removed.
What is used to leak test a tube?
A hydrostatic tube test kit.
At what pressure does a rupture disc relieve?
15 PSIG
Where should a rupture disk be piped?
Outside
How much vapor will remain in a 350 ton chiller after it has been recovered to “0” PSIG?
100 lbs.
How can you speed up the recovery process?
Increase the temperature of the equipment room.
Where is refrigerant added?
Through the lowest point of the system such as the evaporator charging valve.
What happens if you introduce liquid refrigerant into a system that is under a deep vacuum?
It will cause the refrigerant to boil and the water to freeze.
