Cleveland SteamCraft V, Service Manual

Page: 63 / 96

CET-16 Service Manual Page 61
For WYE connected units, contacts LI, L2, and L3 close to complete the
circuits to the two 2.56 kW heaters, the right side 5.3 kW heater, and the
300 W fan motor heater. Both front and rear contactors must energize to
operate these heaters.
During steaming cycles, both the front and rear contactors operate. The
front contactor remains energized to operate one 5.3 kW heater and the
fan motor. The rear contactor cycles to operate all other heaters. See
Temperature Control Circuits on page 67.
When measurements are completed, remember to slide the connectors
fully onto the solenoid terminals. Replace the base plate and secure with
the front base plate nut.
LOW VOLTAGE CIRCUITS and CONTROL BOARD
Low voltage components, energized by the 12 VDC power supply,
control an steamer functions through circuits on the control board. As the
wiring diagram (see Table 6-1) shows, temperature sensors and level
probes connect through CON 2
.
The user input switch pad connects
through CON 1
.
CON 3, as described in previous sections, connects the
120 VAC relay control circuits to the contactors and solenoids.
CON 1 Connections
As illustrated in Figure 5-2, the flat cable from the membrane touch pad
panel connects to CON 1 of the control board. Conformal coating
encapsulates this connection to protect it from moisture, and to maintain
its secure contact with the control board. If CON 1 must be disconnected
to test the switch panel, take care when reinserting the connector so that
the pins are not bent and that all seven pins mate correctly with female
connector. Repair the conformal coating with Cleveland Range approved
coating material.
CON 2 Connections
CON 2 provides the connection point for all low voltage functions. The 18
VAC secondary of the transformer supplies power to the control board.
Proper operation of the 18 VAC supply can be noted by illumination of
any of the indicator lights on the front of the control panel.
The 12 VDC power supply, located on the control board, provides
regulated DC power to the generator temperature and drain temperature
thermistors, to the compartment temperature switch, and to the timing,
display and safety circuits. A high frequency (15-20 kHz) section supplies
0.6 VAC to the water level probes.
Printed 4/90
Color Coded Wiring Harness
All lines connecting to CON 2 are bundled in a color coded wiring
harness. Refer to the wiring diagram (see Table 6-1) for a complete
guide to the color code. Note the common ground connection (green
wire) for the three water level control probes. The compartment
temperature switch, generator temperature thermistor, and the drain
temperature thermistor connect to CON 2 with individual wire pans. Both
wires of each pair share the same color. Except for the 18 VAC input,
inadvertent cont.