7.17 Controller; Handling Modules; Controller Troubleshooting - Carrier 69NT40-561-019 Operation And Service Manual

7.17 CONTROLLER

7.17.1

Handling Modules

Do not remove wire harnesses from module unless you are grounded to the unit frame with a
static safe wrist strap.
Unplug all module connectors before per forming 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.
a. Obtain a grounding wrist strap (Carrier Transicold part number 07-00304-00) and a static dissipation mat
(Carrier Transicold part number 07-00277-00). The wrist strap, when properly grounded, will dissipate any
potential buildup on the body. The dissipation mat will provide a static-free work surface on which to place
and/or service the modules.
b. Disconnect and secure power to the unit.
c. Place strap on wrist and attach the ground end to any exposed unpainted metal area on the refrigeration
unit frame (bolts, screws, etc.).
d. Carefully remove the module. Do not touch any of the electrical connections if possible. Place the module
on the static mat.
e. The strap should be worn during any service work on a module, even when it is placed on the mat.
7.17.2

Controller Troubleshooting

A group of test points (TP, see
schematic diagram, Figure
Use a digital voltmeter to measure AC voltage between TP's and ground (TP9), except for TP8.
TP1
This test point is not used in this application.
TP2
This test point enables the user to check if the high
pres sure switch (HPS) is open or closed.
TP3
This test point enables the user to check if the water
pressure switch (WP) contact is open or closed.
TP 4
This test point enables the user to check if the internal
protector for the condenser fan motor (IP-CM) is open
or closed.
TP 5
This test point enables the user to check if the internal
protectors for the evaporator fan motors (IP-EM1 or
IP-EM2) are open or closed.
T-359
CAUTION
!
CAUTION
!
Figure 7.13) are provided on the controller for troubleshooting electrical circuits (see
8.2). A description of the test points follows:
NOTE
TP 6 (IF EQUIPPED)
This test point enables the user to check if the
controller liquid injection valve relay (TQ) is open
or closed.
TP 7
This test point enables the user to check if the
controller economizer solenoid valve relay (TS)
is open or closed.
TP 8
This test point is not used in this application.
TP 9
This test point is the chassis (unit frame) ground
connection.
TP 10
This test point enables the user to check if the heat ter-
mination thermostat (HTT) contact is open or closed.
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