Det-Tronics U7602B-P Unitized UV Flame Detector/Controller - Manual (Page 17)

A coating of lubricant should also be applied to the
threads on the detector enclosure before re-assem-
bling the detector housing. This will both lubricate the
threads and help to prevent moisture from entering
the detector housing. Do not use silicon based lubri-
cant. Lubricant is available from Det-Tronics.
TROUBLESHOOTING
NOTE
When the U7602 is used with external monitoring
equipment, the equipment that monitors the Fault
relay contacts should have a 5 second time
delay during power-up to avoid nuisance fault
annunciation.
When a fault is indicated by the U7602, the first steps
that should be taken to correct the condition are:
1. Check to make sure that power is reaching the
unit.
2. Make sure that all optical surfaces (the viewing
window and oi ring on the detector housing) are
clean and in good condition. Clean these sur-
faces regardless of how they appear, as some UV
absorbing substances are not readily visible.
3. Check to make sure that there are no sources of
extraneous UV in the area that may be causing
problems.
If the problem is not in the wiring or power supply, all
optical surfaces are clean, and there is no extraneous
UV present in the area, then further troubleshooting is
necessary. The procedure below allows the defective
component (either the detector module or the con-
troller module) to be isolated. Table 3 contains a
description of conditions, and a corresponding expla-
nation and remedy to the problem. Knowing the cur-
rent output is a helpful tool when using Table 3 to
troubleshoot. The current output is available at termi-
nal 3 on TB3 (see Figure 11 or 12).
CAUTION
All fire protection equipment for extinguishing
systems controlled by the U7602 must be dis-
abled before beginning this phase of trou-
bleshooting.
In hazardous locations, input power must be dis-
connected before removing the U7602 housings.
For protection from shock hazards, always dis-
connect input power before removing or replac-
ing modules.
1. Perform the “System Startup/oi Test” procedure.
If the detector remains inoperative:
a. Remove input power to the U7602.
b. Remove detector housing and detector mod-
ule.
c. Install a known good detector module,
replace the detector housing and repeat the
“System Startup/Manual oi Test” procedure.
2. If the detector remains inoperative the controller
section should be checked.
a. Remove input power to the U7602.
b. Remove controller housing.
c. Remove controller module as follows:
1. Loosen four mounting screws holding
controller module.
2. Slide controller module from bulkhead,
disengaging the connector (see Figure 1).
d. Inspect for broken or loose wires. Correct
any faults and re-install the controller module,
making sure it is securely mounted in the
bulkhead and that the connector is engaged
(see Figure 1).
e. If no faults were found in step 2.d. above,
install a new controller module, making sure it
is securely mounted in the bulkhead and that
the connector is engaged.
f. Replace controller housing. Ensure that the
housing is tightened with the O-ring fully seat-
ed to maintain the watertight and explosion-
proof integrity of the detector.
g. Apply input power and repeat the “System
Startup/oi Test” procedure.
After troubleshooting and correcting any faults in the
detector or controller, the complete “System
Startup/oi Test” procedure should be performed
before returning the system to normal operation.
Do not attempt to repair the detector module or con-
troller module. Return all faulty modules to the factory
for repair.
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