KeepRite K40-CU-IM-13, Инструкция по установке и обслуживанию

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7
Electrical Information
WARNING
All wiring and connections to the unit must be made in accordance with national as well as local electrical codes
and by-laws.
Electrical wiring should be sized in accordance with the minimum circuit ampacities shown on the unit
nameplate and applicable electrical codes. The unit power connections are approved for copper wire only.
Connect the field power supply through a fused branch circuit disconnect switch. The entering service fuse must
not exceed the maximum overcurrent protection (MOP) value on the unit data plate.
Field connected control circuit wires are terminated directly at the control circuit terminal block in accordance
with the appropriate wiring diagram.
Voltage at the unit terminals must not vary more than the allowable variation during start-up and while under full
load. If the voltage is normal at the supply with the compressor not running and drops considerably when the
switch is closed and the motor is trying to start, there is a high resistance due to undersized wires or faulty
connections. Voltage drop between inoperative and full load must not exceed 3% of line voltage. In addition, the
phase imbalance at the motor terminals should be within 2% on three phase units.
60 Hz Supply 50 Hz Supply
Power Allowable Variation Power Allowable Variation
115-1-60 103-127 V 100-1-50 90-110 V
208/230-1-60 197-254 V 200/220-1-50 190-242 V
208/230-3-60 187-254 V 200/220-3-50 180-242 V
460-3-60 414-506 V 380/400-3-50 342-440 V
575-3-60 518-632 V
All systems should use a liquid line solenoid valve (installed at the evaporator) and should be energized by the
room or fixture thermostat. For systems with a defrost time clock, the liquid line solenoid and thermostat should
be energized by the time clock. Initially set the defrost time clock (model 8145) as follows:
Air defrost evaporators; 3 per day (every 8 hours) with the time termination at 45 minutes.
Electric defrost evaporators; 4 per day (every 6 hours) with time termination set (Fail Safe) at 30 minutes.
Check that the wiring from the defrost termination thermostat is wired to terminal “X” on the clock and terminates
the defrost cycle when the evaporator coil reaches approximately 55
o
F. The fan delay thermostat wiring should
also be checked for proper operation. This ensures that all water droplets have been refrozen to the coil before
the evaporator fan starts back up.
Note: The above settings are guidelines only and must be re-adjusted to suit local field conditions and actual
evaporator equipment specifications.
Refer to the evaporator installation manual for further information.
An evaporator airflow interlock is recommended on some installations so that the compressor will pump down
and shut off in the event that the evaporator fan is off for any reason. This is wired into the control circuit in
series with the thermostat and solenoid valve.
Refer to the following wiring diagrams for typical air defrost and electric defrost wiring arrangements.
WARNING
Any deviation or change to the electrical components or wiring as supplied on the original equipment, or
noncompliance with the voltage and phase balance requirements without written authorization will void the
warranty.