1 HVACR214 – Electrical for Oil Oil Solenoid Valves

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HVACR214 – Electrical for Oil

HVACR214 – Electrical for Oil

Oil Solenoid ValvesOil Solenoid Valves

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The Solenoid ValveThe Solenoid Valve

• A solenoid valve is an electronic valve.• A coil of wire is energizes and creates

magnetism.• The magnetism either opens or closes a

valve.• A valve that is open when de-energized is

considered a normally open valve.• A valve that is closed when de-energized is

considered a normally closed valve.

• A solenoid valve is an electronic valve.• A coil of wire is energizes and creates

magnetism.• The magnetism either opens or closes a

valve.• A valve that is open when de-energized is

considered a normally open valve.• A valve that is closed when de-energized is

considered a normally closed valve.

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The Solenoid ValveThe Solenoid Valve

• Used in both older and newer high pressure burners.– Older burners this is a field installation– Newer burners this valve is included with the burner

• The valve has two purposes– Delay the flow of oil to the burner at startup– Provide a clean shutoff of the flow of oil at

shutdown.

• Used in both older and newer high pressure burners.– Older burners this is a field installation– Newer burners this valve is included with the burner

• The valve has two purposes– Delay the flow of oil to the burner at startup– Provide a clean shutoff of the flow of oil at

shutdown.

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Solenoid ValveSolenoid Valve

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Solenoid ValveSolenoid Valve

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Delay at startDelay at start

• The oil pump is set at 100psi or 140psi in most cases.

• This pressure is based upon the burner motor operating the pump at full RPMs.

• There is a brief period at the start of the burner cycle that the motor, pump, and air fan are not moving at full speed.

• Thus, the oil delivered to the combustion chamber would not be at the correct pressure or velocity.

• The oil pump is set at 100psi or 140psi in most cases.

• This pressure is based upon the burner motor operating the pump at full RPMs.

• There is a brief period at the start of the burner cycle that the motor, pump, and air fan are not moving at full speed.

• Thus, the oil delivered to the combustion chamber would not be at the correct pressure or velocity.

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• The oil solenoid valve remains closed until the burner motor, the burner fan, and the pump all reach the correct operating speeds.

• The solenoid then opens and allows the correct pressure and air mixtures to occur in the combustion chamber.

• This can also be used as a pre-purge in high efficiency boilers.

• If used as a pre-purge the primary control must be setup for this pre-purge or it will trip.

• The oil solenoid valve remains closed until the burner motor, the burner fan, and the pump all reach the correct operating speeds.

• The solenoid then opens and allows the correct pressure and air mixtures to occur in the combustion chamber.

• This can also be used as a pre-purge in high efficiency boilers.

• If used as a pre-purge the primary control must be setup for this pre-purge or it will trip.

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• If you are at a customers oil furnace or boiler and are not able to solve a rough ignition problem through setting of pressures, cleaning, and air adjustment install an oil solenoid valve and the problem will go away.

• If you are at a customers oil furnace or boiler and are not able to solve a rough ignition problem through setting of pressures, cleaning, and air adjustment install an oil solenoid valve and the problem will go away.

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Clean shutoffClean shutoff

• When the call for heat is complete the burner shuts down.

• There is a brief period of time where the pump is not delivering the correct oil pressure to the nozzle.

• The oil will “drip” out of the end of the nozzle and cause a buildup of carbon on the end of the nozzle and in the combustion chamber.

• When the call for heat is complete the burner shuts down.

• There is a brief period of time where the pump is not delivering the correct oil pressure to the nozzle.

• The oil will “drip” out of the end of the nozzle and cause a buildup of carbon on the end of the nozzle and in the combustion chamber.

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Clean shutoffClean shutoff

• The use of the oil solenoid valve causes a clean shutoff. The valve will close at the end of the call for heat and before the pump and burner loose pressure.

• The use of the oil solenoid valve causes a clean shutoff. The valve will close at the end of the call for heat and before the pump and burner loose pressure.

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Mechanical installationMechanical installation

• The oil solenoid valve is placed on the jet line between the oil pump outlet and the nozzle assembly.

• You will need a second ¼” line to complete this installation.

• The oil solenoid valve is placed on the jet line between the oil pump outlet and the nozzle assembly.

• You will need a second ¼” line to complete this installation.

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Electrical InstallationElectrical Installation

• For clean shutoff purposes the oil solenoid valve is wired to the burner motor line from the primary control.

• Do not wire to a the ignition transformer line if separate on the control as the ignition transformer may not be operational through the entire cycle.

• For clean shutoff purposes the oil solenoid valve is wired to the burner motor line from the primary control.

• Do not wire to a the ignition transformer line if separate on the control as the ignition transformer may not be operational through the entire cycle.

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• For a delayed ignition or pre-purge you must either:– Use a primary control that has a separate line for

the solenoid valve.– Use a solenoid valve with an internal delay

timer.

• Make sure you test any installation prior to leaving the job. Run it through several cycles to be sure the delay will not trip the CAD cell safety.

• For a delayed ignition or pre-purge you must either:– Use a primary control that has a separate line for

the solenoid valve.– Use a solenoid valve with an internal delay

timer.

• Make sure you test any installation prior to leaving the job. Run it through several cycles to be sure the delay will not trip the CAD cell safety.

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Documents

1 HVACR214 – Electrical for Oil Oil Solenoid Valves