Thermo King CRR-40 119, Руководство пользователя

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121
Electrical Maintenance
Unit Wiring
Inspect unit wiring, wire harnesses, and the
controller during pre-trip inspection and every
1,000 operating hours to protect against unit
malfunctions due to open or short circuits. Look
for loose, chaffed or broken wires on the unit;
open or short circuits and damaged components
on the controller printed circuit board.
Inspect electrical contactor points for pitting or
corrosion every 1,000 operating hours. Repair or
replace as necessary.
High Pressure Cutout Switch
A high pressure cutout switch is located on the
compressor discharge service manifold of the
compressor. If the discharge pressure becomes too
high, the switch opens the ground circuit to the
compressor contactor coil:
• Compressor STOPS immediately.
Evaporator and con-denser fans continue
normal operation.
• Controller determines that a high pressure
cutout switch or compressor motor
internal overload protector is open when
the unit current draw during compressor
operation is normal and then decreases by
7 amps for more than 3 seconds.
• After 1 minute, the controller LCD display
shows a High Pressure Cutout message
after 1 minute:
- High Pressure Cutout Check Condenser
Probe: Condenser Fan On/Off switch is
ON and the condenser temperature is low.
- High Pressure Cutout Check Condenser
Fan: Condenser Fan On/Off switch is ON
and the condenser temperature is high.
- High Pressure Cutout Check Water
Cooling: Condenser Fan On/Off switch is
OFF.
• After 1 minute, the controller also
energizes the compressor contactor so the
compressor will restart when the over-load
condition is corrected (switch resets) if
power is available.
• If the switch remains open for 5 minutes,
the controller also turns ON the Alarm
LED and records Alarm 37, Total Power
Consumption Too Low.
High Pressure Cutout Switch:
Opens: 2240 +/- 70 kPa, 22.4 +/- 0.7 bar, 325
+/- 10 Psig
Closes: 1590 +/- 70 kPa, 15.9 +/- 0.7 bar, 230
+/- 10 Psig
To test the switch, rework a gauge manifold per
“High Pressure Cutout Manifold” illustration.
1. Relief Valve, P/N 66-6543
2. O-ring, P/N 33-1015
3. Adapter Tee (Weather Head No.552X3
Figure 28: High Pressure Cutout Manifold
AJA1434