UA Local 140 Practice Test 2 Flashcards
In the hot gas bypass control method, which system component is bypassed?
condenser
The purpose of combustion testing is to perform all EXCEPT which of the following?
condition air through the air handler
The purpose of combustion testing is to perform all EXCEPT which of the following?
two dissimilar metals welded together
Which system component is used to prevent all strip heaters from energizing at the same time?
sequencer
What is the temperature rise across a warm air heat exchanger that is outputing 150,000 Btu’s with 2,000 CFM flowing across the heat exchanger?
69 Degrees
What is the acceptable voltage output of a thermocouple in a standing pilot boiler?
20-30 mV
. Which boiler can be brought through standard doorways and assembled in place?
cast iron sectional
What is needed in a hot water boiler to allow for the expansion of water?
a compression/expansion tank
To prevent priming in a steam boiler, the horizontal steam main should be a minimum of what distance above the NOWL?
24 inches
Normal maintenance of a gas fired burner includes all EXCEPT which of the following?
drilling out gas orifices
The boiler should____while testing low water cutoff safeties
automatically shut down
Follow which of these methods when adjusting a gas regulator to increase outlet pressure?
adjust clockwise to increase
When starting a boiler, the technician finds that the burner mainfold pressure is below normal, but with the burner “off’ the gas supply pressure is normal. What may be the problem?
a clogged regulator vent line
What is the kW rating of the following heating element?
3.8 kw
Volts2/ohms
Which of the following components is used to prove fan operation before electric duct heaters are energized?
sail switch
Which of the following is NOT a benifit of using an SCR type electric resistance heater controller?
reduced installation cost
Which of these instruments is used to measure the pressure in a naturally vented stack?
draft gauge
In starting up a chilled water system, which should be the first piece of equipment to start?
chilled water pump
What is the proper fill pressure for a system that is 100 ft above the PRV?
47 psig
.47 per ft
What is the purpose of adding glycol to a solar heating system?
Allow adequate freeze protection
Which of these is the part of the centrifugal pump that spins and forces water through the system?
impeller
Which of these is NOT a step that should be taken before starting a pump?
remove coupled guard
Which of the following is not a symptom of a water logged expansion tank?
erratic burner operation
On centrifugal pumps, if it is necessary to reduce pump flow temporarily, do so using which method?
throttle the discharge
Which instrument is needed to check the freeze protection level of a solar hydronic system?
refractometer
The water loop on a water-to-ground geothermal loop is typically made out of which type of material?
PVC
Basic types of heat pumps, classified as their heat source and the medium being heated, include all EXCEPT
water to air to water
On a water source heat pump, the refrigerant circuit has a lower than normal discharge pressure and a higher than normal suction pressure. Which is most likely the defective part?
reversing valve
Higher than normal water loop temperature would lead to which of the following conditions?
high subcooling
Higher than normal water loop temperature would lead to which of the following conditions?
boiler to ignite
A system containing one cooling tower, one water cooled condenser, and one pump is classified as which
type of system?
closed
A water coil generally should be piped to provide flow.
counter
If the water flow to a water cooled condenser is reduced, what will happen to the temperature difference across the condenser?
it will increase
A thermostatic steam strap that fails in a closed position may cause which problem to a heating unit?
water logged
Thermostatic traps are opened and closed by which device
flexible bellows
Which of the following is not a type of steam trap
mechanical
what is the purpose of a bypass on a steam regulator
maintains steam pressure if the regulator fails
which of the following is not a type of steam regulator
electric
Which of these conditions could result from condensate in steam lines?
water hammer
What is the purpose for installing a vacuum breaker valve in an automatically controlled steam heating system?
it limits the vacuum to the pump and prevents vacuum to the system