5C: Sequence Of Operation; 5C.1: Start Up; 5C.2: Shut Down - Quantum 67ACW2-134 Owner's Manual

Owners Manual
The superheat is calculated as the difference between the temperature of the suction refrigerant
and the saturated temperature corresponding to the suction pressure, as illustrated below:
Suction temperature (measured) t: _____________ °C
Suction Pressure (measured): _____________ kPa
Saturated temperature (property table) t
Superheat (calculated) t-t

5c: Sequence of Operation

The following sequence of operation is typical. It can vary depending upon options.

5c.1: Start Up

With the control circuit supply on, 220-240V power is applied through the control circuit fuse to
the compressor crankcase heater (if applicable), the compressor motor protection and the primary
of the 24V control circuit transformer. The 24V transformer provides power to the microprocessor
controller. When a remote time clock, manual switch or the unit controller turns on the hot water
pump, the flow switch will close once satisfactory flow rate is achieved. If the hot water
temperature is below the stage-on temperature, and all equipment protection devices are closed,
the unit will start. The controller will operate the unit in response to the water temperature, any
reset signals that may be present and any equipment protection signals that may occur.

5c.2: Shut Down

When the controller senses that the correct water temperature has been reached, the liquid line
solenoid valve will be de-energized. The compressor, liquid injection solenoid valve 1, and the fan
will be de activated, and the machine will be in the hysteresis state. The compressor crankcase
heater will energize when the compressor is shut down (if applicable).
The Machine can also be turned off via the on/off switch mounted on the left side of the cabinet.
The digital controllers display will be off. Please be aware that turning the on/off switch to the
position OFF does not cut the power to the unit. Be sure to isolate the unit from the power supply
should any work be required inside any enclosure of the unit.
Document Number : QDC0049PD-5
Quantum Energy Technologies
: _____________ °C
g
: _____________ °C
g
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