Nortec Industries GS Series manual Servicing The Unit, Service Checks Combustion Blower, Burner

The switch board must be replaced into the same position as before cleaning and the tie -wrap must be used to hold the float chamber in position.

SERVICING THE UNIT

Caution: Disconnect power before servicing this appliance.

Caution: Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation.

The combustion chamber, heat exchanger and flue baffles are all fabricated from stainless steel and do not require internal cleaning.

Should the main burner fail to light, or flame is not detected during the first trial for ignition period, the gas valve is de-energized and the control goes through an interpurge delay before another ignition attempt. The control will attempt two additional ignition trials before going into lockout. The valve relay will be de-energized immediately, and the combustion blower will be turned off.

SERVICE CHECKS

COMBUSTION BLOWER

The combustion air blower motors are permanently lubricated and do not require lubrication. Clean out any dust that has accumulated in the blower housing using an air gun.

BURNER

The burners are made of ceramic fabric material and operate in the infrared mode. Depending on the environment, the burner(s) may require removal of lint or grease-laden dust periodically. This may be achieved by removing the burner and applying pressurized air to the external surface of the material. Refer to the Servicing Section related to burner removal.

Flame Sensor

Flame current is the current which passes through the flame from the sensor to ground. The ignition module must detect a minimum flame current of 0.7 microamps or a flame proving lockout will occur. To measure flame current, connect an DC micrometer to the FC- FC+ terminals on the module. Meter should read 0.7 uA or higher. If meter reads below “0” on scale, meter leads are reversed. Disconnect power and reconnect meter leads for proper polarity.

NOTE: Proper polarity of supply voltage to the unit is necessary for flame sensing to occur. Oxidation on flame sensing rod can reduce measured current. The oxidation can be cleaned from the sensing rod using steel wool or an emery cloth.

Igniter Check

If the igniter is suspected of being defective then the following test may be carried out;

1.Ensure that the power and gas is switched off before servicing.

2.To test the igniter, disconnect the igniter leads from their terminal connections.

3.Using a multimeter set the Ohm’s scale and place one of the meter leads on one of the igniter wire ends and the other meter lead on the end of the other igniter wire.

Gas Valve Setting

The gas valves used in the GS series humidifier are negative-pressure-regulated valves. The valve setting listed on the product rating plate is shown relative to atmosphere – this setting will always remain constant.

The valves come preset from the factory for the correct gas type. If an adjustment is required, use the following steps:

1.Remove the screw from the pressure port marked “out” on the back side of the gas valve.

2.Connect a hose from a digital manometer (or an inclined manometer capable of reading below 0.1”w.c.) to the “out” pressure port.

3.Activate the humidifier and measure the gas valve pressure once the valve is energized and a flame is established in the combustion chamber. Verify this pressure to the pressure listed on the unit specification label.

4.If the pressure needs adjusting, remove the locking cap on the top of the gas valve.

5.Below the locking cap is an adjustment screw. Increase the pressure by turning the adjustment screw clockwise, decrease by turning counter-clockwise.

NOTE: The pressure will fluctuate slightly as the unit operates, especially with very sensitive measuring devices. Use the mean pressure value as the set pressure.

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