Symptom
Indicator
Possible Cause
Remedy
Frequent Watch
Dog Failures or
Chirping Flame
Relay
Flame Relay chirps
or Watch Dog LED
Flash Slowly
Detector not properly
grounded
Ground the detector to a clean
ground (instrument ground if
possible).
Frequent
system reset
(Brown Out)
ALL LEDS Resets
together frequently.
High AC / Inductive Load
on Alarm or Flame relay
contacts
Install Surge suppressor across
relay contacts.
Radio Frequency by a
cable of a Motor/Switch/
Noise-Source
Install Detector away from any
possible noise source
Isolate & eliminate sources of
electrical noise
4-20mA Signal
Loss
Steady 4mA output
15VDC (LED11) off.
No Feedback to DCS
System / PLC Monitoring
System.
Check 15VDC using DVM @J3
connector with respect to GND.
Remove external wiring from
terminals and measure mA current.
Check 4-20 ma return wire is not
grounded at DCS end or DCS is
not providing 24 VDC on these
terminals.
No Change in
Profile
No change in Profile
LEDs status of P1
& P2.
External PLC System
and Amplifier GND not
common.
Check connection with J12.
Verify control system contacts
wired to P1, P2 terminal are
potential free when disconnected
from IDDX.
Manually Connect P1 / P2 signal to
GND and Check Profile Status on
Termiflex / LEDs.
BMS system
Fails
for Flame
Detection
Flame LED On
& Flame Relay
Contact Open
Input Power not sufficient
to pick up relay.
Check for Loose wiring.
Check Input power using DVM.
It should be >21VDC.
BMS system
Fails
for Alarm
De
tection
Alarm LED Off &
Relay Contact Open
Input Supply not sufficient
to pick up relay.
Check for Loose wiring.
Check Input power using DVM.
It should be >21VDC.
IDDX Amplifier
Non-operational
WDT LED OFF
All power LED ON.
Firmware suspended.
Manually Reset / Power ON-Off
Amplifier.
Firmware Not Loaded.
Contact Forney Service/Support
team
All LEDs Off.
24VDC Supply is
disconnected.
Check Input supply Voltage using
DVM. Verify Polarity
26
372001-24 Rev. A
IDDX Flame Detector Amplifier Manual
