Maintenance - Honeywell U2 User Manual

CAUTION
ALL ADJUSTMENTS SHOULD BE CARRIED OUT
BY A QUALIFIED PERSON.
BMS interlock(s) may require temporary bypass during
configuration. This operation should be carried out
under supervised conditions and limited to minimum
time. Remove bypasses as soon as configuration and
setup is completed.
1. Adjust all sensor gain settings to 50.
2. Go to Flame ON menu. Set this to 800.
3. Go to Flame OFF menu. Set this to 600.
4. Go to the AUTO GAIN menu, tap enter, scroll to "yes"
then tap enter again.
5. Wait as instructed by the display.
After the burner is in service and boiler load is above 90%,
perform the following for discrimination tests and adjustments.
6. Go to the AUTO FILTER menu, tap enter.
7. Turn off the burner being monitored as instructed by the
display.
8. Tap enter, scroll to "yes" then tap enter again.
U2 COMBINATION VIEWING HEAD AND SIGNAL PROCESSORS
HIGH FREQUENCY
FLICKER ZONE
LOW FREQUENCY
FLICKER ZONE
Fig. 6. IR viewing head location.
9. Ensure the current flame count is less than the FLAME
OFF value.
10. Restart the burner being monitored.
11. Ensure the current flame count is greater than the
FLAME ON value.

MAINTENANCE

The UV tube 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 tube sensor
is considered terminated when the sensitivity becomes lower
then 50% of the initial value.
A monthly sensitivity check is suggested to determine if the
UV tube sensor's life is terminated. The reading of the U2
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 are used
during each sensitivity check. If it is determined that the
sensitivity is below 50% of the initial value (terminated life of
sensor), the sensor should be replaced.
DETECTOR IN POOR
SIGHTING POSITION
15
DETECTOR IN GOOD
SIGHTING POSITION
(PARALLEL SIGHTING)
BURNER NOZZLE
CENTERLINE
M33285
66-2071—02