El Oído Interno

The Fulton motorised high/low control is designed to improve the efficiency of the boiler by switching the firing rate from high fire (when there is low steam pressure in the boiler) to low fire

(when the boiler reaches a high steam pressure).

The systems major components comprises; two stage gas valve, motorized air damper unit and two stage steam pressure switch.

CAUTION

The adjustment of the air gate control motor or the two stage gas valve should only be carried out by qualified personnel, incorrect adjustment could result in damage to the pressure vessel and/or the production of harmful combustion gases.

1.2 Operation

With the steam pressure switch preset to the high and low fire operational requirements of the system, and the boiler operating normally, steam pressure will gradually increase until the high pressure limit is reached, the pressure switch will then switch the two stage gas valve and the air damper motor to the low fire position.

The boiler will continue to operate at low fire until the steam pressure falls to the low pressure limit setting on the pressure switch, at this point, the gas valve and the air damper will switch the boiler into high fire mode, the sequence of high fire / low fire is regulated automatically with no routine

maintenance required.

Note: Should the boiler attain the off setting of the on/off control pressure switch, the burner will switch

off on low fire and then restart in the normal way on high fire.

1.3 Additional Controls

Air Damper Motor High / Low Fire Cams Air Damper Housing

2.2 Air Damper Motor - Factory Cam Settings (see 2.3 Setup procedure)

Terminal Position Degrees

N1 High Fire Motor Cam 45O

N2 Low Fire Motor Cam 10O N5 High Fire Interlock Cam 40O N6 Low Fire Interlock Cam 15O

2 Commissioning

(commissioning should only be carried out by a qualified Fulton Service Engineer).

To achieve the ideal combustion efficiency and gas input rates, a gas flow rate meter is required to measure the fuel input to the boiler.

2.1 Fuel Input Rates

Model 6 8 10 15 20 30 40 50 60 Low Fire m3_{/h 3.5 4.7 5.8 8.7 11.6 11.6 23.2 29.0 34.8} ft3_{/min. 2.1 2.8 3.4 5.1 6.9 10.3 13.7 17.1 20.5} High Fire m3_{/h 7.0 9.3 11.6 17.4 23.2 34.8 46.4 58.1 69.6} ft3_{/min. 4.1 5.5 6.8 10.2 13.7 20.5 27.3 34.2 41.0} Note: Boilers are pre-commissioned before leaving the factory to ensure optimum gas input rates and com-

bustion values.

Note: The high fire interlock cam should always be set approximately 5O _{lower than the high fire cam posi-} Motorised High/Low Control. continued.

Blue cam N7 not used Red cam N6

Red cam N5

Red cam N4 not used

Red cam N3 not used

Yellow cam N2

Yellow cam N1

2.3 Setup Procedure

1. Set the cams on the air damper motor to the initial position.

Start the boiler and wait until the motor and gas valve have driven to high fire.

Adjust the main (primary) air gate to achieve the best combustion with the least buffeting in the furnace.

2. Using the low fire hold switch, hold the boiler in low fire.

The air damper motor should move to its low fire position and the high fire light on the control panel extinguish, indicating the gas and air input rates have been reduced to approximately half the high fire input rate.

Note: If gas flow rate equipment is available, the low fire gas input rate should be adjusted to the correct

value (see fuel input rates table) by rotating the black 1st stage partial adjustment ring located below the 2nd stage solenoid.

3. The ideal low fire CO2 constituent of the flue gases is 8 - 10.5%.

Place an exhaust gas analyser into the flue, reduce or increase the amount of air entering the boiler as required, by adjusting the low fire cam (N2) position.

Note: The reaction of the motor to a change in cam positions is:

Reduced air: adjust the cam to reduce the amount of air entering the boiler, the reaction of the

motor will be immediate.

Increased air: adjust the cam to increase the amount of air entering the boiler, switch the low fire

hold switch off. When the motor has driven back to high fire turn the low fire hold switch on, the damper will drive back to its new low fire position.

Adjust the cams until the correct CO₂ figure is achieved.

Note: any adjustment to the cam positions requires an adjustment to its interlock cam position.

4. Switch off the low fire hold switch.

Note: if gas flow rate equipment is available, the high fire gas input rate can now be set (see fuel input rates

table) by adjusting the pressure control screw located under a protective cover on the black electrical con- nection block. 5. The high fire CO2 constituent of the flue gases is 10 - 10.5%. Place an exhaust gas analyser into the flue, reduce or increase the amount of air entering the boiler as required, by adjusting the high fire cam (N1) position. To reduce the amount of high fire air, the damper will have to be driven to its low fire position and back again, before it takes up its new position. Ensure that the high fire interlock cam N5 is always set approximately 5O _{below the high fire motor position cam N1.} Record all cam settings and the high and low fire final gas elbow pressures for future reference. 6. Adjust the pressure switch (PS2) to the high/low switch over point.

Motorised High/Low Control. continued.

5.0 Spare Parts

Part No. Description Qty Model

10366 Casting, scroll 1 6 - 15 13195 Transformer, TRK2P COFI 1 15 14437 Switch, air pressure, DL5A 1 15 14485 Motor, damper, A30 045Y 1 15 14486 Inlet, scroll 1 15 14487 Fan, 200x40x16 1 15 14489 Coupling, air gate 1 15 5-10-000480 Airgate, high/low 1 15 11327 Switch, low fire hold 1 15 14493 Valve, gas, MB-ZRD(LE)410 B01 1 15

Motorised High/Low Control. continued.

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