Carrier 69NT40-561-300, Operation And Service Manual

Page: 145 / 174

7–29 T-365
Figure 7.20 Autotransformer
7.24 CONTROLLER
7.24.1 Handling Modules
CAUTION
!
Do not remove wire harnesses from module unless you are grounded to the unit frame with a
static safe wrist strap.
CAUTION
!
Unplug all module connectors before performing arc welding on any part of the container.
The guidelines and cautions provided herein should be followed when handling the modules. These precautions
and procedures should be implemented when replacing a module, when doing any arc welding on the unit, or when
service to the refrigeration unit requires handling and removal of a module.
1. Obtain a grounding wrist strap (Carrier Transicold P/N 07-00304-00) and a static dissipation mat (Carrier
Transicold P/N 07-00277-00). The wrist strap, when properly grounded, will dissipate any potential static
buildup on the body. The dissipation mat will provide a static-free work surface on which to place and/or ser-
vice the modules.
2. Disconnect and secure power to the unit.
3. Place strap on wrist and attach the ground end to any exposed unpainted metal area on the refrigeration unit
frame (bolts, screws, etc.).
4. Carefully remove the module. Do not touch any of the electrical connections if possible. Place the module on
the static mat.
5. The strap should be worn during any service work on a module, even when it is placed on the mat.
7.24.2 Controller Troubleshooting
A group of test points (TP, see Figure 7.21 ) are provided on the controller for troubleshooting electrical circuits
(see schematic diagram, Section 8 ). A description of the test points follows:
NOTICE
Use a digital voltmeter to measure AC voltage between TP’s and ground (TP9), except for TP8.
Dual Voltage
Modular
Autotransformer
Circuit Breaker (CB-2)
230-Volt
460 VAC Power
Receptacle