Study Material

During a pressure relief inspection of a refrigeration system, a technician checks the setting of a safety relief valve. At what percentage of the maximum operating pressure should this valve be set to ensure compliance?

• 25% of the maximum operating pressure

• 50% of the maximum operating pressure

• 75% of the maximum operating pressure

• 100% of the maximum operating pressure

A technician is troubleshooting a make-up air rooftop unit and needs to understand the function of the isolation damper. What is its primary role in maintaining indoor temperature balance?

• To regulate combustion air flow

• To enhance exhaust efficiency

• To close the intake during combustion

• To prevent cold air from entering a warm building

An HVAC technician is diagnosing a thermostat issue. The system requires both heating and cooling functions. What distinguishes a heating/cooling thermostat from one that controls only heating?

• It uses a single control wire

• It requires four control wires

• It activates a delay start function

• It uses three control wires

A maintenance worker is replacing a fan in a power-assisted draft appliance. Which information must be provided to ensure the correct fan is ordered?

• Serial number of the appliance only

• Model and serial number of the appliance and fan

• Voltage of the fan

• Manufacturer of the fan

A technician is inspecting a forced draft appliance and is asked to identify where upshot burners are typically found. Which appliances use upshot burners?

• Residential air handlers

• Low-pressure steam boilers

• Chilled water plants

• Gas ranges, water heaters, and boilers

While servicing a steam system, the technician must identify the burner used in large water tube boilers. Which type is typically used?

• Upshot burner

• Closed burner

• Inshot burner

• Large water tube burners

An intermittent pilot spark system locks out. How can a technician reset the module to resume operation?

• Pressing the ignition button twice

• Turning the power off to the module

• Holding the gas valve reset

• Resetting the thermostat

While installing a make-up air unit, which safety device ensures the unit shuts down if airflow becomes excessive?

• Rollout switch

• High velocity air switch

• High limit thermostat

• High temperature limit switch

To determine the correct sequence of operation for a heating system, what should the technician consult first?

• Homeowner manual

• Wiring diagram

• Manufacturer’s literature

• Thermostat label

In an intermittent pilot spark sequence, what happens if the pilot does not light within the set time?

• The gas valve remains open

• The module shuts off the gas and spark

• The thermostat takes over ignition

• The blower fan starts regardless