AGL_Unit_ZX_Small_E_Rev03
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2.10 Main control & safety features
Copeland ZX Small refrigeration units feature a whole range of control and safety components.
2.10.1 Suction pressure control
The unit is switched on and off by means of a PS1 low-pressure switch.
Caution:
The unit does not have any cycling protection. The adjustment of the low-pressure switch
must be done in such a way that the unit will not switch on and off more than 10 times per hour
during normal operation.
2.10.2 Motor current overload protection
No protection is installed in the unit. The installer has to choose an external current protection
device for the compressor motor based on motor characteristics and data.
2.10.3 Fixed high-pressure switch PS4
This is a non-adjustable protection device designed to prevent the compressor from operating
outside of its safe high-pressure range.
▪
ZXME with BOM 301:
Cut-out 26 bar, cut-in 20 bar
▪
ZXME with BOM 302 & ZXLE:
Cut-out 28 bar, cut-in 21 bar
The compressor is switched on automatically when the pressure falls below the cut-in value.
2.10.4 Adjustable low-pressure switch PS1
This device protects the system against low pressure operation. It must be adjusted depending on
running conditions and potential special requirements. The compressor envelopes published in
Select must be respected at all times.
2.10.5 Crankcase heater
A crankcase heater is provided with the Copeland ZX Small refrigeration unit. The crankcase
heater is automatically activated by reverse contact when the compressor is not running.
2.10.6 Liquid line assembly
The liquid line assembly includes a filter drier and a sight glass/moisture indicator.
2.10.7 Room thermostat
A dedicated electrical connection is pre-wired for operation with a room thermostat. The jumper
must be removed to activate the room thermostat
– see wiring diagrams in
Appendix 1
.
