Emerson Copeland EazyCool ZX Series - 2.10 Compressor motor protection; 2.11 Compressor pressure protection

C6.1.6/1108-0509/E 9
2.10 Compressor motor protection
The electronic board protects the compressor motor against the following:
 Over current
 Loss of any one phase
 Incorrect phase rotation
If the compressor motor current exceeds a pre-defined current limit (non-adjustable), then the
electronic board shuts down the unit and generates an error signal to the LED’s on the board.
For this function to operate, two of the main phase supply lines to the compressor (compressor
via the contactor) are routed through the current abnormality coils.
2.11 Compressor pressure protection
2.11.1 High pressure
A sensor is registered by the electronic board. The sensing device is a non-adjustable, high-
pressure switch that will open in the event of an abnormally high discharge pressure (above
28 bar).
 The unit will stop and then restart automatically after a 3-minute delay and after unit
pressure has decreased to 24 bar.
 After 5 successive HP cut-outs over 1 hour, the unit will lock-out.
2.11.2 Low pressure
In a similar way to the high-pressure sensor, the electronic board registers the switching action
of a non-adjustable, low-pressure switch that will open in the event of an abnormally low suction
pressure (below 1 bar).
 The unit will stop then restart automatically after a 3-minute delay and when unit
pressure attains 2 bar.
2.12 Other inputs to the board
2.12.1 Customer-supplied control (thermostat)
The electronic board accepts a normal 220 volt AC input On/Off signal (such as the switching
action of a normal commercial thermostat) and relays a similar action as an output to the
compressor contactor in the case of a thermostat-controlled system (refer to the wiring diagram
in section 3.2.2). If the system is controlled by low-pressure cut-out for a multiple evaporator
system and/or pump down system, the electronic board accepts signals directly from an
adjustable low-pressure switch (optional).
Safety
instructions
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