C7076A,D ADJUSTABLE SENSITIVITY ULTRAVIOLET FLAME DETECTORS
6. Secure the swivel mount (if used), or tack weld the sight
pipe. Do not weld the sight pipe permanently into place
until you have accomplished the spark hold-in and pilot
7. Remove the plug from the Flame Current meter jack.
8. Replace the rear cover plate and tighten the four screws
Multiburner System Using C7076A Detector (Flame
1. Complete steps 1 through 8 under Single Burner
System above for each burner.
2. With all A sensitivity controls set to MAX position and all
burners firing at full load, select one burner and proceed
a. Shut down the chosen burner, then note the flame
b. Loosen the locking nut on Sensitivity Control A.
c. Gradually reduce the sensitivity by turning Control A
counterclockwise until the flame relay (in the flame
safeguard control) drops out.
Fig. 17. Set up for Sensitivity Controls A and B adjustments, C7076A Detector.
For multifuel systems, use one sensitivity control for each fuel.
Follow steps 2 and 3 above for each fuel.
W136A TEST METER
(SET AT SPL)
d. Relight the burner and note the flame signal
reading. The difference between the new reading
and the initial reading in step a represents the
degree of flame discrimination.
e. Repeat the run-shutdown-dropout procedures
(steps 2a-d) until the optimum setting has been
Hand tighten the locking nut on Sensitivity Control
A, then tighten another 1/4 turn, but do not
NOTE: If the sensitivity control on a detector is reduced to
MIN position and flame discrimination cannot be
achieved, insert an orifice plate in the sight pipe. An
orifice of the proper diameter will reduce the
ultraviolet radiation reaching the detector so that the
sensitivity can be adjusted to effect flame
3. Repeat step 2 for Sensitivity Control A on each burner.
4. Repeat step 2 for Sensitivity Control B (if used) on each
burner. Verify that Sensitivity Controls A and B on each
detector are properly indexed by the system fuel
selector, firing rate switch, etc.