Edwards TCU 40/80 - Page 55

Table 14 - Miscellaneous fault conditions
Indicator
Host fail signal.
Supplies fail signal to
the host interface
when any of the
following occur:
Host wam signal.
Supplies wam signal
to the process tool
when any of the
following occur:
Temperature
controller process
value blinks.
Failure to cool.
Possible causes
Unit in STOP mode
FACILITY POWER Fail
FACILITY WATER Fail
CIRCUIT BREAKER Fail
COMPRESSOR Fail
TEMPERATURE Fail
FLOW Fail
Coolant LOW LEVEL
FAULT
Coolant NORMAL
LEVEL OVER-FILL
Coolant LOW LEVEL
RTD wired incorrectly to
the interface connector
J72J3.
Terminals 4 and 5 are not
linked on the interface
connector J72J3.
Incorrect RTD type being
utilized.
Temperature controller
parameters are not set to
factory defaults.
Main cooling solenoid valve
(SVl)fail.
Relay board failure.
Moisture is in the system.
Action
Refer to the "Faults indicated by the front panel
LED indicators" on page 44.
Refer to the "Faults indicated by the front panel
LED indicators" on page 44
Verify that the remote RTD is wired correctly.
Refer to the "Remote Interface wiring
schematic" on page 56.
Verify that terminals 4 and 5 on connector J72J3
are linked.
Refer to the "Remote Interface wiring
schematic" on page 56.
Verily that the RTD is 100 ohm European.
Verify temperature controller PID settings.
Refer to the "Temperature controller" portion of
the System Check on page 21.
Verify 24 VAC is present between wire #16 (J4-5)
on the relay board and wire #4 (TB1). 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 current draw of the solenoid is not above 1
amp.
Verify that the resistance of the coil is about 8 Q.
If necessary, replace the coil (EHVI part no.
P3303O3OO).
Verify that the main cooling relay (CR15) comes
on when the unit is in cooling mode.
Verify that the moisture indicator in the sight glass
is green. If it appears yellow in color remove power
from the unit and notify an Edwards service
representative.
Hazard
Type 3
Type 3
Type 2
Type 4
Type 3
Type 2
TCU 40/80 Temperature Control Unit
49