Cambridge Engineering, Inc.
50
M-Series Technical Manual
BLOWER CLEANING
The blower wheel should be examined for accumulation
of dust on the blades. These surfaces must be kept clean.
Dirt accumulation will result in significant air flow
reduction and/or possible imbalance of the blower wheel.
Prolonged imbalance CAN result in catastrophic failure
of the blower wheel and other related components.
BURNER CLEANING
The Cambridge Engineering burner is for the most part
self-cleaning. However, if the application is extremely
dirty or dusty, it may become necessary to periodically
clean the burner. Remove and clean the burner in accor-
dance with the following recommended procedures.
1. Turn the heater disconnect switch off. Close the man-
ual gas supply shut-off valve.
2. Loosen the union in the gas train.
CAUTION:
The igniter is made of silicon carbide material and
should be handled with care to avoid breakage.
3. Disconnect the ignition cable from the burner and then
remove the flame rod and the igniter.
4. Examine the flame rod ceramic for cracks and replace
if necessary. Clean the flame rod element with emery
cloth to remove oxidation.
5. Remove the fasteners that secure the burner to the
housing. The burner will then be free to slide out.
m
CAUTION:
Be sure to take necessary safety precautions (such
as wearing eye protection, etc.) before attempting
this step.
6. Clean the burner by back-flushing using high pressure
air (40-80 PSI). Continue back-flushing until dust par-
ticles are completely expelled from the burner.
7. Re-install the burner using the above steps in reverse
order.
GAS VALVE CLEANING
All solenoid valves should be cleaned periodically.
The time between cleanings will vary depending on the
medium and service conditions. In general, if the voltage
to the coil is correct, sluggish valve operation, excessive
noise, or leakage will indicate that cleaning is required.
Refer to step 8, Gas Valve Leak Check, of the Start-up
Procedures (see page 32).
m
WARNING:
In the extreme case, faulty valve operation will
occur and the valve may fail to open or fully close.
IMPORTANT
It is not necessary to remove the valve from the gas
train for cleaning.
m
WARNING:
To prevent the possibility of severe personal inju-
ry or property damage, turn off electrical power,
close the upstream manual gas valve, depres-
surize
the
valve, extinguish all open flames and
avoid any type of sparking or ignition. Vent haz-
ardous or combustible fumes to a safe area before
servicing the valve.
