Vulcan-Hart VL2GPS, VL3GMS, VL2GMS, VL3GAS, VL2GAS, VL2GSS Solid State - Auxiliary Low Level Cut-Off

VL SERIES STEAMER - ELECTRICAL OPERATION

Solid State - Auxiliary Low Level Cut-Off

This control serves as a safety backup to the main water level control (WLC) board to meet Cal-Code and CSD-1 code requirements. The auxiliary control provides auxiliary low level cut-off protection to shut off the heat source in case the water level drops below the low level cut-off (LLCO) probe. A single LLCO probe is connected to the auxiliary control.

The auxiliary water level control (WLC) has input voltage (120VAC) across terminals L1 and L2 to power the transformer primary. On one side of the transformer secondary, power is provided to the control by a series path through chassis ground. The other side of the transformer secondary (12VAC) supplies power to one side of the internal relay LLCO. As water enters the boiler, it becomes part of the auxiliary water level control’s circuit. When the water level in the boiler reaches the LLCO probe, the circuit is completed.

When the main power switch is turned ON, power is supplied to the auxiliary WLC board but no switching occurs. On CSD-1 models, the low water level indicator light (amber) on the boiler control box comes on.

When the water level reaches the low level cut-off (LLCO) probe, the LLCO relay is energized and illuminates the LLCO LED. With the LLCO-2 contacts closed the auxiliary heating control is then energized. The LLCO relay will remain energized and its LED will stay lit until the water level in the boiler drops below the LLCO probe.

When the boiler stops filling, press the manual reset button on the boiler control box. On CSD-1 models, this energizes the low water relay, turns off the low water light and energizes the heat source auxiliary control. On Cal-Code models, this closes and locks the manual reset switch contacts to energize the heat source auxiliary control.

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