Timed/Manual Switch (11, Figure 6-5); Relay - Cleveland steamcraft 21-CET-8 Service Manual

Page 72 Model 21 -CET.8 Service Manual
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Figur 5-4. ON/OFF Switch
TIMED/MANUAL Switch
(11, Figure 6-5)
Relay K1
(9, Figure 6-5)
Setting the ON/OFF switch to ON supplies power to relay K1 and power to one side
of the:
- heater contactor
- heater condenser
- fill solenoid
- drain solenoid
- rinse solenoid
These components can be activated by control components:
- relay K1
- TIMED/MANUAL switch
- timer control
- high level float switch
- low level float switch
• In units with the electronic key pad timer, the ON/OFF switch in the ON position
supplies power to one side of the timer countdown circuits through the
compartment thermal switch. The ON/OFF switch also supplies power to the 24-
volt transformer which provides control power to the key pad timer.
• In units with the mechanical dial timer, the ON/OFF switch set to ON supplies power
to one side of the 3-second timer and buzzer for operation by the timer control.
Setting the ON/OFF switch to OFF removes power from the 120 VAC components
that control the steaming cycles, and starts the 3-minute timer circuit, which starts
steam generator blowdown and float cylinder rinse.
Setting the ON/OFF switch to ON supplies power to the center terminals of the
TIMED/MANUAL switch. In the TIMED position (Figure 5-5), the TIMED/MANUAL
switch energizes the timer control circuit In the MANUAL position, the
TIMED/MANUAL switch energizes the heater contactor and condenser solenoid,
unless either the float low level switch or the high temperature limit switch is open.
• When electronic key pad units are in MANUAL mode, the opening of either the float
low level switch or the high temperature limit switch interrupts power to the
condenser solenoid and heater contactor.
• When mechanical timer units are in MANUAL mode, the opening of either the float
low level switch or the high temperature limit switch interrupts power to the heater
contactor only, the condenser solenoid remains energized.
Setting the ON/OFF switch to ON energizes relay K1, dosing the contacts of the
relay. This energizes the drain solenoid dosing the drain valve. Energizing relay K1
also energizes one side of the fill solenoid. The fill solenoid can be activated by the
high level float switch.
Setting the ON/OFF switch to OFF deenergizes relay K1, opening its contacts. This
prevents power from the 3-minute timer circuit from energizing the drain solenoid,
and dosing the valve, during generator blowdown.
Printed 12/90