I.C.E. BMA-136 HBR User Manual

Page 6

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6. The timers TD-1 - TD-5 are factory set but you should check them to ensure they have not moved during transit to job


6A. Normal setting of high limits are -165


7. Operate unit through paint mode by pushing in the system “on” push button. The unit should operate as per sequence of


7A. Pilot
The Protectorelay monitors the pilot flame through the flame rod. A minute current is sent from the relay through the

flame rod, and trough the pilot flame to “ground”. The relay detects the current flow and acts to open the safety valve as
required. When no flame exists, current cannot flow and the relay acts to close the valve. Current flow depends only on
flame contact on the rod: temperature of the rod is of no importance.

Since the flame rod is a current-carrying conductor, it must be free of any contact with conductive parts of the pilot
burner. Insulator must be clean, dry and free from cracks. While the flame rod is made of a heat resistant alloy it may,
after long service, deteriorate to the point of flame contact. Check for serious corrosion or loss of metal. It must be
tight enough in the insulator to maintain its position. Do not use too much force or the insulator may crack.

Proper operation of the flame rod can be checked by measuring the flame rod current; refer to flame safeguard
instruction sheet with unit. Lacking a micrometer, a check can be made with an operating burner through all its normal
phases. Relay response should be prompt with no chattering or drop out.

The spark rod (Midco Burner see figure 5 for gap setting, Maxon Burner spark ignitor No. 18075) produces a high
tension arc at the correct location for lighting the pilot. Ignition transformer must be rated for 6000 Volts, 20
Miliampers secondary, minimum.

The spark rod or spark ignitor, must be free of contact with conductive parts of the pilot burner. Insulator must be clean,
dry and free of cracks. Check the spark rod for serious corrosion or loss of metal. It must be held tightly enough in the
insulator to maintain its position.

Gap must be 1/16” to 3/32” ( see figure 5). Setting can also be checked by cycling the pilot. Ignition must be prompt
and positive. Do not allow careless positioning to cause arc of flame rod; serious relay damage would result.

If the spark ignitor on Maxon burners shows deterioration of ignitor points the complete spark ignitor should be
replaced (part No. 18075).

8. If pilot tries for ignition, but locks out, the air proving switches (high and low) that are mounted across the profile plate,

should be checked to make sure that the proper amount of air is flowing through the unit. Check to make sure blowers
are running in the proper direction. This can be checked by placing a differential gauge across the profile plate of the
burner section. If the pressure drop is between .30” W.C., and .95” W.C., these switches should be made, then check
pilot to ensure proper flame. Check instruction sheet for flame safeguard system.

Pilot adjustment screw is in the Thermax shut-off valve. When setting, adjust for the best reading, then open pilot set
screw slightly.

8A. Main flame supervision: With units that have more than three feet of burner from point or supervision, a second flame

rod will be on the main burner. This switching is done with a time delay relay (see wiring diagram). This can be
disconnected for testing for pilot, or you have to ensure main flame by opening up the firing valve within 15 seconds
after pilot solenoid is powered. As supervision will switch from pilot to main flame in that time. Check to ensure that
unit will lock-out in the event of main flame failure on low-fire by closing main firing valve.

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