VICI ITC - Manual (Page 19)

connected to AC ground. Failure to do so may cause a shock hazard, or controller
malfunction, or both.
Locate the ITC where it will not be subjected to abrupt changes in ambient
temperature. This will improve the controlled temperature stability.
When installing the thermocouple, be sure to observe electrical restrictions noted
in Section 2.2.
Actual installation consists of, first, thinking about what must be done, then
connecting the heater, and finally inserting the thermocouple. After this is done,
turn it ON and play with the system. Notice whether or not corrections need to be
made in such areas as thermocouple location, bandwidth adjustment, etc. Enjoy!
(If you’re not enjoying yourself, call us. We’ll try to help in any way we can.)
2.6 Troubleshooting and Schematic Diagram
Troubleshooting the ITC is straightforward, in most cases. The device can be
thought of as being divided into two sections; instrumentation and power circuitry.
Problems with the power circuitry are the most easily identified, and can be
handled with a minimum of electronics experience. Isolation and repair of mal-
functions in the instrumentation circuitry require sophisticated test equipment and
extensive electronics expertise. For this reason, it is recommended that the factory
be consulted when the following procedures are of no help.
2.61 Situation: PWR ON indicator fails to illuminate; instrument does
nothing.
A 1/2 amp fuse is employed to fuse the instrument’s DC power supply. If this fuse
is blown, the PWR ON indicator will not illuminate, and the instrument will not
perform any functions. The fuse is located at the left rear corner of the enclosure.
(Refer to Figure 6, Item 10.) If the ITC persists in blowing this fuse, consult the
factory.
2.62 Situation: TCPL indicator ON continuously; no power applied to
heater
When the TCPL indicator is ON continuously, the instrument thinks an open circuit
has developed in the thermocouple. As a consequence, the ITC will refuse to
apply power to the heater. The thermocouple is connected to the instrument by a
barrier strip, designated B1. (Refer to Figure 6, Item 9.) Be certain these connec-
tions are snug. As a second consideration, be certain that proper connection to
AC ground is made in any case where the thermocouple measuring junction
contacts metal. If this is not done, the TCPL circuit can sometimes be fooled into
believing there is a malfunction. As a final consideration, disconnect the thermo-
couple, and check it for electrical continuity. If the problem is not located, consult
the factory.
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