Operating principles of the raw gas burner – I.C.E. 3 OSDs User Manual

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8. Burner on low fire only.

a) Check TD2 timer low fire timer should be set at 20 seconds.

b) Check DC volts on #55 and #57, if above 5 V.D.C. modulation valve may be defective, replace.

9. See Maxitrol literature to trouble shoot the system.

NOTE: On custom built units the number designation may change.

Carefully check wire diagram supplied with unit.


1. Purge light “off”, dry cycle light not “on”.

a) Check and replace.

2. Burner not on, no power on #40.

a) Check dry high limit (HL-B).
b) Check low exhaust inter lock.
c) Check high and low profile air switches.

d) Check profile damper should be closed below burner.

3. Power on #40 burner not on. See instruction spray mode 5, 6, 7, and 8.

4. Burner on, but will not operate up to selector set point.

a) Check to see if temperature delay timer TD4 is powered and switch over from #12 to #11, on the

Maxitrol, amplifier is completed.

b) Check discharge sensor.
c) Refer to Maxitrol trouble shooting guide provided with this manual.


The raw gas burner is designed to operate in a duct of flowing fresh air. Fuel gas is fed directly to the burners; kinetic
energy of the air stream furnishes combustion air. The burner must be installed to fire with, and parallel to, the air
flow. By virtue of velocity impact and suction generated by the diverging shape of the combustion baffles, air is
induced into the air ports in the combustion zone. The air supply is constant though only that which mixes with the gas
flowing from the burner ports, takes part in combustion.

When a very small quantity of gas is admitted to the burner, sufficient mixing takes place in the low fire slot within the
burner, casting and combustion takes place in this zone. Since the low fire zone is contained within the burner casting
it is effectively shielded from fire disrupting uncontrolled air entry.

As the gas is increased the flame progresses into the intermediate fire zone where an additional supply of air is
available. High or full capacity, mixing occurs at the larger air ports of the high fire zone augmented by air spilling
over the end of the baffles.

On a reduction of gas supply the reverse sequence takes place. The flame receding to a location of lesser air supply
until the low fire zone is reached. The system above is suitable for a turn down range of approximately 30 to 1.

With the suction by the blower there is a pressure in the gas manifold of less that zero at low fire. Therefore, when
checking the manifold pressure you will find that the pressure will range from approximately 4” W.C. to less than
zero, when the unit is modulating from high to low fire.

This manual is related to the following products: