Thermo King 098916, Руководство по обслуживанию

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Electrical Maintenance
124
Reversing Power Phase on
MAGNUM Units
Use the incoming power cable leads to reverse the
power phase. This is recommended on
MAGNUM units because the Jumper J18 does not
reverse power to the scroll compressor. This
protects against the possibility that the compressor
will be out of phase with the condenser and
evaporator fans when the unit is plugged into a
new power supply.
To reverse the Power Phase Complete complete
the following steps:
1. Turn the unit 460/380V main circuit breaker
off.
2. Disconnect unit power cord from power
supply.
3. Relocate the position of the white and black
incoming power cord leads at the 460/380V
main circuit breaker.
4. Connect unit power cord to proper power
supply.
5. Start the unit again by turning the unit
460/380V main circuit breaker on and the Unit
On/Off switch On.
6. Check condenser airflow again to confirm
correct fan rotation.
Electric Heaters Malfunction
Six electric heater elements are located
underneath the evaporator coil. If a heater element
is suspected of malfunctioning, check the
resistance of each individual heater element by
performing the following procedure:
1. Turn unit power supply off.
2. Remove unit power plug from power supply
receptacle.
3. Open the control box door.
4. Test the insulation of each individual heater
element.
a. Test all 3 legs of the heater circuit to a
good ground connection. Connect a
calibrated 500 Vdc insulation tester
between each outgoing heater contactor
terminal and ground.
b. If the resistance between any contactor
terminal and ground is below 0.8 meg
ohms, isolate and check the resistance of
each individual heater element.
5. Check the resistance of each individual heater
element.
a. Disconnect and isolate each heater from
the circuit in the control box.
b. Check resistance of each heater with an
insulation tester between each heater and
ground. If the resistance between each
heater and ground is below 0.8 meg ohms,
the heater element is defective. On a
loaded container, remove the defective
heater from service by disconnecting at the
control box. If the container is empty,
remove the evaporator cover from the rear
of the unit and replace the heater or correct
any defective wiring. Repeat step 5a.
NOTE: When repairing heater connections,
protect the new connections from the ingress
of moisture with heat shrink tubing. All
heaters should be secured to prevent contact
with sharp metal edges.
WARNING: The unit will automatically
start and operate if 460/380V power is
present at the main relay board when the
controller is disconnected. To prevent
personal injury from rotating machinery
or dangerous electrical shock from high
voltage controls, disconnect the supply
power to the unit before preparing the unit
for manual emergency mode operation.