Carrier 69NT40-541-001, Операция и обслуживание

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T-316 5–14
5.11 EMERGENCY OPERATION
Operation by the refrigeration controller may be overridden by use of the EMERGENCY BYPASS or by use of the
EMERGENCY DEFROST switch. The EMERGENCY BYPASS switch functions to bypass the controller in the
event of controller failure, The EMERGENCY DEFROST switch functions to bypass the controller and place the
unit in the defrost mode.
5.11.1 Emergency Bypass Operation
To place the unit in the emergency bypass mode, cut the wire tie installed at the switch mounting and place the
EMERGENCY BYPASS switch in the ON position which will in turn activate the Emergency Bypass System (EBS)
control module.
To operate the fans only the MODE switch must be in the FANS ONLY position and the EMERGENCY BYPASS
Switch must be in the ON position.
The EBS module uses the system's safety devices (high pressure switch, motor internal protectors, and heat termi-
nation thermostat) to protect the system while in Emergency Bypass Mode.
CAUTION
!
The unit will remain in the full cooling mode as long as the emergency bypass switch is in the
BYPASS position and the MODE SWITCH is in the FULL COOL position. If the cargo may be
damaged by low temperatures, the operator must monitor container temperature and manually
cycle operation as required to maintain temperature within required limits.
In the ON position the EBS will be enabled. With the MODE SWITCH in the FULL COOL MODE. The following will
occur simultaneously:
1. The EBS switch will enable EBS input.
2. The phase detection circuit will detect the phase rotation and close to provide power to the compressor contactor.
3. The condenser fan contact will close to energize the condenser contactor and provide power to the con-
denser fan motor.
4. The evaporator fan contact will close to energize the high speed evaporator contactor and provide power to
the evaporator fan motor.
5. The EBS electronic module will open the SMV to 100%.
To return the unit to normal operation, place the EBS switch in the NORMAL OPERATION position. When emer-
gency operation is no longer required, re-install the wire tie at the switch mounting.
5.11.2 Emergency Defrost Operation.
To place the unit in the emergency defrost mode of operation, cut the wire tie installed at the switch mounting (see
Figure 3.6 ) and place the switch in the EMERGENCY DEFROST position.
NOTE
1. If the unit is in the emergency bypass cooling mode, the emergency defrost switch will override this
mode and place the unit in defrost.
2. The IN-RANGE LIGHT is de-energized when in the emergency defrost mode.
The switch is a normally open four pole switch which is placed in the EMERGENCY DEFROST position to:
a. De-energize the compressor, condenser fan and evaporator fan contactors.
b. Illuminate the EMERGENCY DEFROST LIGHT.
c. Energize the heater contactor.
d. Illuminate the DEFROST LIGHT.
CAUTION
!
The unit will remain in the DEFROST mode as long as the emergency defrost switch is in the
DEFROST position. To prevent cargo damage, the operator must monitor container tempera-
ture and manually cycle operation as required to maintain temperature within required limits.
To return the unit to normal operation, place the switch in the NORMAL OPERATION position. When emergency
defrost is no longer required, re-install the wire tie at the switch mounting.