VL SERIES STEAMER - ELECTRICAL OPERATION
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e 41 of 88
Electro Mechanical - Auxiliary Low Level Cut-Off
This control serves as a safety backup to the main low level cut-off (LLCO) control to meet Cal-Code
requirements. The operation of the auxiliary control is identical to the main low level cut-off control but performs
a sin
le function: 1) Provide 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 sin
le LLCO probe identical to the LLCO probe on the
main low level cut-off control is connected to the auxiliary control.
The auxiliary control is powered by input volta
e (120VAC) on terminals 1 and 2 which also connect to the
primary side of the internal transformer. The transformer secondary windin
(300 VAC) will provide power to the
internal contactor coil throu
h a series path
oin
from one side of the secondary windin
, throu
h the contactor
coil, throu
h the water level control probe, throu
h the water in the boiler and to the boiler for
round. The other
side of the transformer secondary is attached to
round.
When the main power switch is turned ON, the auxiliary low level control is ener
ized but no switchin
occurs.
When the water level reaches the low level cut-off (LLCO) probe, the internal contactor coil on the low level
control is ener
ized, closin
the contacts on terminals 7 & 8. The internal contactor coil will remain ener
ized
until the water level in the boiler drops below the LLCO probe.
When the boiler stops fillin
, press the manual reset button on the boiler control box. This closes and locks the
manual reset switch contacts to ener
ize the heat source auxiliary control.
