Thermo King KD-II SR, Manual

Page: 11 / 182

Safety Precautions (Rev 04/03)
iii
8. Never use testers consisting of a battery and a light bulb
to test circuits on any microprocessor based equipment.
9. Before connecting or disconnecting the battery, the
microprocessor switch must be turned OFF.
NOTE: The following T.I.P. Procedures may be found in
Operation and Diagnosis Manual TK 41087.
• Replacing and calibrating the return air and discharge
sensor.
• Replacing the µP-T microprocessor.
• Welding on the unit or truck.
Welding of Units or Truck Bodies
When electric welding is to be performed on any portion of
the temperature control unit, truck or truck chassis when the
temperature control unit is attached, it is necessary to ensure
that welding currents are NOT allowed to flow through the
electronic circuits of the unit.
These procedures must be rigidly adhered to when servicing
units to avoid damage or destruction of the controller.
1. Disconnect all power to the unit.
2. Disconnect all wire harnesses from the controller.
3. Switch all of the electrical circuit breakers in the con-
trol box to the OFF position.
4. Weld unit and/or container per normal welding proce-
dures. Keep ground return electrode as close to the area
to be welded as practical. This will reduce the likeli-
hood of stray welding currents passing through any
electrical or electronic circuits.
5. When the welding operation is completed, the unit
power cables, wiring and circuit breakers must be
restored to their normal condition.
High Voltage
When servicing or repairing a temperature control unit, the
possibility of serious or even fatal injury from electrical
shock exists. Extreme care must be used when working with
a refrigeration unit that is connected to a source of operating
power, even if the unit is not operating. Lethal voltage
potentials can exist at the unit power cord, inside the control
box, at the motors and within the wiring harnesses.
Precautions
1. Be certain the unit On/Off switch is turned OFF before
connecting or disconnecting the standby power plug.
Never attempt to stop the unit by disconnecting the
power plug.
2. Be certain the unit power plug is clean and dry before
connecting it to a power source.
3. When working on high voltage circuits on the tempera-
ture control unit, do not make any rapid moves. If a tool
drops, do not grab for it. People do not contact high
voltage wires on purpose. It occurs from an unplanned
movement.
4. Use tools with insulated handles that are in good condi-
tion. Never hold metal tools in your hand if exposed,
energized conductors are within reach.
5. Treat all wires and connections as high voltage until a
meter and wiring diagram show otherwise.
6. Never work alone on high voltage circuits on the tem-
perature control unit. Another person should always be
present to shut off the temperature control unit and to
provide aid in the event of an accident.
7. Have electrically insulated gloves, cable cutters and
safety glasses available in the immediate vicinity in the
event of an accident.