unit 14 automatic controls

A low pressure control has a "high event" and a "differential" setting. The technician wants the system to turn on at 28 psig and shut down at 2 psig. What would be the proper settings?

• high event: 28 psig, differential: 2 psig

• high event: 2 psig, differential: 2 psig

• high event: 28 psig, differential: 26 psig

• high event: 2 psig, differential: 28 psig

If the suction pressure of a system is 60 psig and the oil pump outlet is 85 psig, what is the net oil pressure?

• 60 psig

• 25 psig

• 85 psig

• 145 psig

Where would a water regulating valve that is controlling head pressure be installed?

• water circuit at inlet of condenser

• discharge line at outlet of compressor

• suction line

• liquid line close to the condenser

When a water regulating valve is used to control the head pressure of a water-cooled system, the valve's spring is acting against which pressure to modulate the water flow?

• head pressure of the system

• water pressure

• suction pressure

• atmospheric pressure

The purpose of a heat anticipator is to ____.

• anticipate a sudden rise in temperature

• keep the thermostat warm

• reduce the temperature swing of a conditioned space

• ensure that the system transformer does not overheat

The difference between system overshoot and system lag is called ____.

• room temperature

• temperature rise

• temperature drop

• temperature swing

Which of the following can cause a compressor's internal overload to open?

• system undercharge

• system overcharge

• faulty starting component(s)

• all of the above

The heat anticipator in the thermostat control circuit in the heating mode is active when the ____.

• heating contact is open

• heating contact is closed

• fan switch is open

• fan switch is closed

The heater in the thermostat control circuit in the cooling mode is active when the ____.

• cooling contact is open

• cooling contact is closed

• fan switch is open

• fan switch is closed

The thermostat heat anticipator is set ____.

• according to the current draw of the fan motor

• by the manufacturer

• according to the current draw of the gas valve

• according to the total amp load on the control circuit