6--19
T-334
c. There is no internal protector for this transformer
design, therefore, no checking of the internal protec-
tor is required.
d. Using a voltmeter, and with the primary supply circuit
ON, check the primary (input) voltage (460 vac). Next,
check the secondary (output) voltage (230 vac). The
transformer is defective if output voltage is not avail-
able.
6.20 CONTROLLER
6.20.1 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 per-
forming arc welding on any part of the con-
tainer.
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 dissi-
pate any potential buildup on the body. The dissipa-
tion 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.
6.20.2 Controller Trouble-Shooting
A group of test points (TP, see Figure 6--19) are
provided on the controller for trouble-shooting electrical
circuits (see schematic diagram, section NO TAG). A
description of the test points follows:
NOTE
Use a digital voltmeter to measure AC voltage
between TP’s and ground (TP9), except for
TP8.
TP1
This test point enables the user to check if the controller
unloader solenoid valve relay (TU) is open or closed.
TP2
This test point enables the user to check if the high
pressure 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.
TP 6
This test point is not used in this application.
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 enables the user to check power to the
suction modulator valve.
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
termination thermostat (HTT) contact is open or closed.
1
2
3
4
1. Controller Software Programming Port
2. Mounting Screw
3. Controller
4. Test Points
Figure 6--19 Controller Section of the Control Box
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