Edwards TCU 40/80

Table 14 - Miscellaneous fault conditions (continued)
Indicator
Remote START/STOP
fail.
Hour counter fail.
Remote setpoint
enable fail.
Possible causes
Refrigerant leak.
Temperature controller
parameters are not set to
factory defaults.
Temperature controller is
not functioning properly.
J72J2 interface connector is
wired incorrectly.
Remote START/STOP
jumper not removed
Hour counter not recording
operating time.
Absence of 24 VAC supply
to interface connector J72J2
or interface connector is
wired incorrectly.
Relay board failure (CR14).
Temperature controller
parameters are not set to
factory defaults.
Temperature controller not
functioning properly.
Action
Visually check for signs of compressor oil on the
base, insulation, around the compressor service
valves, and on all refrigeration pipework.
Use a halogen leak detector to leak check all
accessible refrigeration pipework and the
compressor service valves.
If compressor oil is noted or a leak is located
remove all power to the unit and contact an
Edwards service representative.
Verify temperature controller PID settings.
Refer to the "Temperature controller" portion of
the System Check on page 21.
Verify that the OUT 2 lamp on the front of the
temperature controller is ON when the unit is in
cooling mode.
Replace the temperature controller if necessary
(EHVI part no. P43008000).
Verify proper wiring of connector J72J2.
Refer lo the "Remote Interface wiring
schematic " on page 56..
Verify that the remote START/STOP jumper
located across terminal TB1-I on terminal block
TB1 is removed. To do this, opening of the
electrical drawer is necessary. This will activate
the drawer interlock switch and shut the TCU
40/80 down.
Notify the tool operator prior to opening the
electrical drawer.
Verify 24 VDC across the wires connected to the
hour counter (wire #28 and wire #29). To do this,
removal of the front access panel is necessary.
Replace the hour counter if necessary (EHVI part
no. P43144900).
Verify the host 24 VAC supply to pin 3 and pin 4
on connector J72J2.
Refer to the "Remote Interface wiring
schematic" on page S6..
Verify that the remote setpoint enable relay (CR14)
is on.
Verify temperature controller PID settings.
Refer to the "Temperature controller" portion of
the System Check on page 21..
Verify temperature controller is in remote mode.
The AUX lamp on the front of the controller should
be ON.
Replace the temperature controller if necessary
(EHVI part no. P43008000).
Hazard
Type 2
Type 2
Type 4
Type 3
Type 4
Type 4
Type 3
Type 4
Type 2
Type 4
50
TCU 40/80 Temperature Control Unit