Chapter 6 77
Maintenance
Testing and Replacing the Ignitor Assembly
This section describes how to test and replace the ignitor assembly (Part #282624) if
the PFPD does not ignite when appropriate gas flows and the ignitor current have
been set. Figure 6.2 shows the part of the ignitor assembly housed in the detector cap.
1. Remove the flame arrestor. Look down through the vent and verify that the
ignitor coil is not glowing when the ignitor current is off.
2. Using WinPulse, note the current PFPD ignitor current. Set the ignitor current
to zero. Disconnect the ignitor cable from the Detector Controller.
3. Allow the detector cap to cool to room temperature.
4. Use the ohm scale on an ohm-volt meter to determine if the ignitor is open.
Measure the resistance between the leads on the ignitor cable by inserting the
probes into the 3-pin connector that connects to the Detector Controller. If it
is open, showing very large resistance, replace the ignitor assembly.
5. Using the ohm-volt meter, measure the resistance between one lead and the
top of the detector cap to see if it is shorted to the detector cap. If it appears
shorted, look through the exhaust vent hole on the detector cap and verify that
the ignitor is centered in the exhaust vent hole. If it is not centered, the ignitor
may be shorting to the wall of the ignitor cap. If possible, loosen the ignitor
assembly to center the ignitor in the exhaust vent hole. Recheck to see if it is
still shorting. If it is still shorting out, replace the ignitor assembly.
6. To replace the ignitor assembly, detach it from the detector cap using a U/qy"
wrench to loosen the attachment nut.
7. Install the ignitor, tightening the attachment nut until the coil can be seen
centered in the exhaust vent hole. Verify that the ignitor is not shorting to the
detector cap and that the ignitor assembly is not “open.”
!
WARNING:
Handling the
PFPD while it is
hot can cause
serious burns.
Exhaust Vent Hole
Detector Cap
#246900
Figure 6.2. Ignitor Assembly
Detector Cap
Mounting Screws
#295287C
Ignitor Assembly
#282624
Attachment Nut
Flame Arrestor
#286393
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