Honeywell C7076D Product Data page 20

C7076A,D ADJUSTABLE SENSITIVITY ULTRAVIOLET FLAME DETECTORS
REPLACING THE COIL AND SHUTTER ASSEMBLY
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 coil near the bottom of the chassis (Fig. 22).
3. Cut the two white coil wires as close to the coil as
possible.
4. Remove the mounting screw from the base of the coil
and shutter assembly.
5. Turn the chassis over and locate the sensing tube.
6. Gently push the alignment guide away from the tube
(just enough to free the tip of the sensing tube) and
swing the tube out from the chassis as far as it will go
(Fig. 21).
7. Remove the other mounting screw from the base of the
coil and shutter assembly (Fig. 22).
8. Carefully slide the coil and shutter assembly out of the
chassis.
NOTE: It may be necessary to move some of the
transformer leadwires out of the way in order to slide
the coil and shutter assembly past them.
95-8269—1
ALIGNMENT GUIDE
OCTAL PLUG
Fig. 19. Replacing the ultraviolet sensing tube.
191053
TAB ON
ULTRAVIOLET
TUBE BRACKET
SENSING TUBE
TUBE SOCKET
9. Slide the new coil and shutter assembly into place.
Make sure its part number and voltage rating are
correct.
10. Remove about 1/4 in. (6 mm) of insulation from each of
the two short, white leadwires still connected to the octal
plug.
11. Using wire nuts, connect one of the coil wires to one of
the short, white leadwires on the plug and connect the
other coil wire to the other short, white leadwire.
12. Insert the two mounting screws in the base of the coil
and shutter assembly and tighten them securely.
13. Swing the sensing tube back into place in the chassis.
The alignment guide will snap into place around the tip
of the tube.
14. Reinstall the plug-in electronics chassis as specified in
Replacing the Plug-in Electronics Chassis, above.
15. Close the master switch.
IMPORTANT
Be very careful not to kink or otherwise damage the
shutter.
20
PLUG-IN ELECTRONICS
CHASSIS
M20764