Burnham K50 manual Normal Operation Sequence

thermocouple proves pilot flame and, in the absence of such, will cool and, within 45 to 90 seconds, will cause the L62GB-3C Pilot Safety Switch to which it is connected, to break the electrical circuit to the main gas valves as well as shut off the flow of gas to the pilot. Thus, 100% shut-off is achieved.

The 5015B thru 5024B boilers utilize two Thermocouple Control Systems that are interconnected electrically thru all operating and safety controls. Should any of the aforementioned controls break the power supply circuit, both Thermocouple Control Systems would be de-energized. The proceeding paragraph describes the function and operation of each Thermocouple Control System. Should a pilot failure on one Thermocouple Control System occur, the other Thermocouple Control System would not be affected. Thus main burners on the unaffected side would ignite on a “call for heat” and would continue to operate until the operating control was satisfied.

a.LIGHTING INSTRUCTIONS

(1)Make sure that all main manual and pilot valves have been off for at least five (5) minutes.

(2)Set operating and limit controls to desired setting.

(3)Open pilot valve.

(4)Depress button on pilot safety switch to which it is connected and hold lighted match on pilot. Hold button in for at least one minute, or until the pilot burner remains lit after the button is released. Repeat for second pilot when boiler is so equipped.

(5)Open manual main shut-off valve(s).

(6)Turn on main electric switch.

NORMAL OPERATION SEQUENCE

5006B thru 5013B, see Fig. 55

5015B thru 5024B, see Fig. 56

When operating control (A) calls for heat, it energizes main gas valves (B), starting burner operation.

The burners will operate until operating control (A) is satisfied. The high limit control (C), will stop burner operation in case of excessive steam pressure (steam boiler) or excessive boiler water temperature (water boiler).

Low water cut-off (D) will stop burner operation if the water level in boiler drops below the lowest safe level.

The pilot safety switch (E), connected to main gas valve (B), prevents operation of the main burners in case the pilot flame becomes extinguished. Pilot safety switch (E) provide for 100% shut-off of gas supply.

Fig. 55

WIRING DIAGRAM - 6 THRU 13 SECT. BOILERS

THERMOCOUPLE CONTROL SYSTEM

CANADA ONLY

69