Fig. 18. Replacing the plug-in electronics chassis in the C7076 Flame Detector.
REPLACING THE PLUG-IN ELECTRONICS CHASSIS IN THE C7076D
NOTE: Removing and replacing the plug-in electronics
chassis in the C7076D is identical to the procedure
for the C7076A, above, with the exception of steps 2,
8 and 9, below.
1. Open the master switch to interrupt all power to the
2. Remove the six screws securing the cover plate to the
rear of the housing and remove the cover plate.
3. Remove the four screws securing the plug-in electronics
chassis and pull the chassis out from the housing.
4. Align the slot in the top of the new chassis with the key
in the housing.
Make sure the part number and the voltage rating of
the new chassis are correct.
5. Insert the new chassis in the housing and firmly push it
all the way in Make sure the octal plug on the chassis is
securely seated in the socket in the housing.
6. Reinstall the four screws that hold the chassis in the
housing and tighten them securely.
7. Close the master switch and perform the Adjustment
and Checkout procedures previously specified.
8. Replace the rear cover plate on the detector. Make sure
that the tips of the sensitivity control extensions on the
rear cover are positioned properly to engage the slots of
the respective sensitivity controls on the rear of the
electronics chassis without altering their adjustments.
C7076A,D ADJUSTABLE SENSITIVITY ULTRAVIOLET FLAME DETECTORS
1 C7076D HAS SCREWS, NOT STANDOFFS.
PLUG-IN ELECTRONICS CHASSIS
(CHECK VOLTAGE RATING)
9. Reinstall the six screws in the cover plate and tighten
REPLACING THE ULTRAVIOLET SENSING TUBE
1. Open the master switch and remove the plug-in
electronics chassis as specified in Replacing the Plug-in
Electronics Chassis, above.
2. Locate the sensing tube near the top of the chassis.
(See Fig. 19.)
3. Gently push the alignment guide away from the tube
until the tip of the tube is free.
4. While holding the alignment guide away from the tube
tip, grasp the tab on the tube bracket and swing the tube
out from the chassis.
5. Pull the tube out of its socket.
6. Align the three pins on the new tube with the holes in
7. Push the new tube firmly into the socket. Make sure it is
8. Swing the tube back into place in the chassis. The
alignment guide will snap into place around the tip of the
9. Reinstall the plug-in electronics chassis as specified in
Replacing the Plug-in Electronics Chassis, above.
10. Close the master switch and perform the adjustments
Be very careful not to kink or otherwise damage the
shutter (Fig. 19).