Troubleshooting; Maintenance - Honeywell 700 User Manual

TROUBLESHOOTING

Lockout or Faulty VH Indication
If the viewing head produces any pulses during the last one
third of the self-check time, the relay will immediately de-
energize, the display will show "LO" (lockout), and the FAULT
LED will flash on and off rapidly. Exit lockout by pressing
RESET.
If a pulse or pulses come in during the last one third of the
self-check time while the automatic data sampling is taking
place, the automatic process will be aborted, the relay will be
de-energized if it was energized, the display will show "LO"
(lockout), and the FAULT LED will flash on and off rapidly.
Press RESET to exit this.
If a viewing head is disconnected, the display will show "L1."
Reconnect the viewing head and press RESET.
If the signal processor displays "EE" upon power up, it is an
indication that the EEPROM stored data for the viewing head
does not match for the currently connected viewing head. For
further information on this condition, refer to the Parameter
Match Error Section below.
Parameter Match Error
If the signal processor displays "EE" upon power up, it is an
indication that the EEPROM stored data for the viewing head
does not match for the currently connected viewing head. This
error can occur when a different model viewing head is
connected to the signal processor than was previously
connected. As a result, the signal processor discards the
previous stored parameters and loads factory defaults, except
the RELAY ON SETPOINT is set to 31.
Setpoint values and other parameters plus error-checking
codes are stored in EEPROM (Electrically Erasable
Programmable Read Only Memory) in the signal processors.
This data is then error-checked when it is read at power up. If
the data does not match exactly what was previously stored,
the signal processor discards all data, displays "EE", and
loads factory defaults. The RELAY ON SETPOINT is set to 31.
HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD
Since the flame count cannot go this high, the flame relay
cannot be energized. The signal processor can be reset by
changing the RELAY ON SETPOINT to a reasonable value or
by pressing LOAD FACTORY DEFAULTS.
Panel Lock with No VH Connected
The signal processor requires continuous communication with
the connected viewing head. If the viewing head is
disconnected, communication will be lost and the display is
made inoperative where no settings can be examined or
changed. To correct this condition, reconnect the viewing
head to the signal processor and cycle power.
Grounding and Shielding
See "Grounding and Shielding" on page 3 for further
troubleshooting help in regards to proper grounding and
shielding techniques.

MAINTENANCE

(UV tube models Only)
The UV sensor has a limited lifespan. Under extreme
conditions, the lifespan can be as low as 10,000 hours.
However in the most favorable conditions, the lifespan is
50,000 hours or more. The service life of the UV sensor is
considered terminated when the sensitivity becomes lower
than 50% of the initial value.
A monthly sensitivity check is suggested to determine if the
UV sensor's life is terminated. The reading of the signal
processor digital display should be compared to the initial
reading of the unit when it was installed. Ensure similar burner
fire conditions of the application, and that the same gain
settings of the viewing head, are used during each sensitivity
check. If it is determined that the sensitivity is below 50% of
the initial value (terminated life of the sensor), the sensor
should be replaced.
19 66-2069EP—04