Timed Mode Circuit Operation - Cleveland steamcraft 21-CET-8 Service Manual

TIMED Mode Circuit Operation

3. Provides power to relay K1.
Contacts of relay K1 close to energize the drain solenoid and open the drain
valve. Another set of relay K1 contacts close to supply power to the fill solenoid
valve through the high level switch of the float. The fill valve opens to fill the
steam generator.
4a. (Electronic key pad timer units only) Supplies power to one side of the
condenser solenoid and heater contactor.
After approximately 15 minutes , the water level rises to cover the heater
elements. The float low level switch doses and completes the circuit to energize
the condenser solenoid and heater contactor. The contactor closes its contacts
to supply line power to the heater and dryer elements. The unit begins to heat
the water in the generator.
4b. (Mechanical timer units only) Completes the circuit to the condenser solenoid.
The condenser valve doses and supplies water flow to cool the steam-water
drainage from the steamer compartment.
After approximately 15 minutes, the water level rises to cover the heater
elements. The float low level switch doses and completes the circuit to energize
the heater contactor. The contactor doses its contacts to supply line power to the
heater and dryer dements. The unit begins to beat the water in the generator.
5. The water level in the generator continues to rise until the float high level switch
opens. This opens the circuit to the 511 solenoid. The £11 valve doses and the
generator stops filling After 4 to 5 minutes, the generator produces steam, and the
water level in the generator drops. As the water level drops, the high level float
doses the high level switch. The high level switch reenergizes the fill solenoid.
The float and high level switch cycle the fill valve to maintain the proper water
level for steaming.
The heater remains energized and the unit continuously produces steam until the
operator sets the TIMED/MANUAL switch to TIMED or turns the steamer OFF with
the ON/OFF switch.
• Circuit operations with the TIMED/MANUAL switch set to TIMED are described in
the TIMED Mode Circuit Operations section.
• Circuit operations with the ON\OFF switch set to OFF are described in the
Shutdown Circuit Operations section.
Circuit operations in timed mode are s imilar to those in MANUAL mode. The major
difference between the two modes is control of the heater contactor and condenser
solenoids. With the TIMED/MANUAL switch in the TIMED position, the timer circuits
control power to the heater contactor and condenser solenoid. There are differences
between the timed mode circuit operations in units with key pad timers, and units
with dial timers.
Model 21 -CET-8 Service Manual Page 67
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