Det-Tronics R7404 - Troubleshooting; Device Repair and Return

7.1 22 95-8242
Det-Tronics window cleaning solution (part number
001680-001) is designed specifically for cleaning
the optical surfaces of the detector. Avoid the use of
commercial cleaners, since many of them can leave a UV
absorbing residue on the surface.
NOTE
Remove power to the controller or switch the unit to
the Test mode when cleaning the detector windows
to avoid the possibility of false actuation.
Rubber O-rings are used on the detector housings
to ensure the watertight integrity of the detector. The
housings should be opened periodically and the O-
rings inspected for breaks, cracks, or dryness. To test
them, remove the O-rings from the detector housing and
stretch them slightly. If cracks are visible, the O-ring
should be replaced. If they feel dry to the touch, a thin
coating of lubricant should be applied. When re-installing
the O-rings, be sure that they are properly seated in the
groove on the housing.
It is imperative that these O-rings be properly installed and
ingoodcondition.Failuretoproperlymaintaintheserings
can allow water to enter the detector and cause premature
failure. The life expectancy of rubber O-rings can vary
considerably, depending on the amount and nature of
contaminants that are present in the environment. The
person responsible for maintenance of the system must
rely on experience and common sense to determine how
frequently the rings should be inspected. A coating of
lubricant should also be applied to the threads on the
detector enclosure before reassembling the detector.
This will both lubricate the threads and help to prevent
moisture from entering the detector housing.
CAUTION
The O-ring should be lubricated with polyalphaolen
grease, such as GRS-450 made by CPI Engineering.
Silicone based lubricants should never be used if
catalytic type combustible gas sensors are being
used in conjunction with the UV detectors, since
inadvertent use of a silicone lubricant on or near
the combustible gas sensor will cause irreversible
damage to the sensing element.
A test form is supplied at the rear of this manual for
recording maintenance performed on the system.
TROUBLESHOOTING
The Automatic o
i
feature continuously checks the system
for various faults that can occur. If a fault should be
detected, the FAULT LED will turn on.  If the fault is in
the detector or wiring, the upper displays will indicate
which zone and detector is affected. The lower display
will indicate by code number the type of fault. If the fault
isinthemicroprocessorcircuitry,theFAULTLEDwillturn
on, but the displays will remain blank. See Table 5 for a
detailed explanation of the status/fault code numbers on
the lower digital display, and the corresponding detector
identification numbers on the upper digital display.
The R7404 is not designed to be repaired by the
customer in the field. If a problem should develop, first
carefully check for proper wiring and programming. If it
is determined that the problem is caused by an electrical
malfunction, the unit must be returned to the factory for
repair.
RecordallfaultsontheFaultRecordSheetatthebackof
this manual.
DEVICE REPAIR AND RETURN
Prior to returning devices, contact the nearest local
Detector Electronics office so that a Service Order
number can be assigned. A written statement describing
the malfunction must accompany the returned device or
component to expedite finding the cause of the failure.
Pack the unit properly. Use sufficient packing material
in addition to an antistatic bag or aluminum-backed
cardboard as protection from electrostatic discharge.
Return all equipment transportation prepaid to the factory
in Minneapolis.