Repair manual

STEAM COIL WIRING DIAGRAM
HOW THE ELECTRIC LOW WATER SAFETY SHUT-OFF OPERATES ON STEAM
COIL (ELECTRIC OPERATED) STEAM GENERATORS
Operation — Low Water Safety Shut-Off
When Switch S is closed the following operations occur:
1. The primary circuit of Transformer T is energized.
2. When the water level reaches the low water safety cutout
probe extension and the momentary reset switch is
manually closed, Relay Coil RC is energized.
3. When Relay Coil RC is energized, the normally open
contacts close, completing the low water safety circuit
through Contacts 7 and 6. and completing the circuit
through Contacts 3 and 4, energizing Solenoid SV2,
allowing steam to flow into the boiler's steam coil.
If the water level drops below the Low Water Safety Cutout
probe extension, the following occurs:
1. The secondary circuit of Transformer T is broken and the
Relay Coil RC is de-energized. Contacts 7 and 8 and 3 and
4 open, breaking the circuits to Solenoid SV2, thereby
shutting off the flow of steam to the boiler's steam coil.
The steam Solenoid SV2 will not operate until water level in the
boiler is normal and the reset switch is operated.
Operation — Boiler Drain Condenser
To activate the Boiler Drain Condenser System close Switch S
by placing toggle in the down position.
To drain the boiler, open the boiler drain ball valve. The heat
from the boiler drain water will close the normally open Thermal
Switch TS and energize the condenser Solenoid Valve SV3. To
deactivate the Boiler Drain Condenser System open Switch S
by moving toggle to the center off position.