TYPE 956 FLAME DETECTORS
OLD STYLE | NEW STYLE |
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TESTING (cont’d)
NOTE
CELL SOCKET ASSEMBLY
CELL ASSEMBLY
Rotate Cell Assembly counter- clockwise to remove it. To replace it, insert end through notched open-
ing in bracket and rotate clock-
wise. NOTE: If bracket is ever re- BRACKET moved from burner, Cell Assembly
will not fit if bracket is reinstalled backwards.
If indicator of ohmmeter remains steady, read- ings up to 2000 ohms should also be acceptable. Generally, the lower the reading, the better the application, and less likely the chance of burner flame variation causing a safety
d. If resistance of flame detector is over 1000 ohms, it |
may not be able to see the burner flame properly. |
Check alignment of the flame detector through the |
hole in the static pressure disc. Clean this hole if it is |
blocked by foreign matter. Check for broken “F” wires. |
e. If flame detector alignment is good but resistance is |
PART No. OF REPLACEMENT PARTS
Cell only (Old Style) | |
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Cell assembly (New Style) | |
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still high, readjustment of burner flame and/or nozzle |
replacement may be necessary (according to burner |
manufacturer’s instructions). |
4.If safety lockout problem is of an occasional nature the following additional check may be made to insure that flame detector location is not a marginal one:
a.Disconnect flame detector leads from “F” terminals.
b.Attach a jumper wire to one “F” terminal. Start burner. Then immediately connect jumper wire to the other “F” terminal. Burner should continue to run.
c.With burner running, attach flame detector leads to an accurate ohmmeter. Reading of ohmmeter should be below 1000 ohms, and preferably as low as 500 ohms.
!WARNING
Be sure to remove wire jumper after finishing this flame detector check.
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