Cleveland SteamCraft V, Service Manual

Page: 61 / 96

CET-16 Service Manual Page 59
Control Circuits
Relays (K1, K2, K3, K4) mounted on the control board use normally open
contacts to control 120 VAC power to the front/rear contactors and the
water flow solenoids. One side of each contactor or solenoid connects
directly to one side of the 120 VAC secondary of the transformer. Power
to the other side of the contactors and solenoids comes from the control
board through CON 3 with a separate wire to each contactor or solenoid.
Refer to the wiring diagram (see Table 6-1) for the tracer colors of these
wires. One wire (white with black tracer) from the transformer feeds
power through CON 3 to the one side of the contacts of relays K1-K4 on
the control board. When K1, K2, K3, or K4 energizes, its contacts close
to complete the circuit through CON 3 and energize the associated
contactor or soleniod. In turn, contacts of the engerized contactor close
to turn on the heaters and fan motor. Solenoids, when energized, open
the water flow valves.
NOTE
False digital multimeter (DMM) voltage readings will result
from improper test connections. DO NOT disconnect CON
3 from the control board when checking voltage output
from CON 3 to solenoids or contactors. The load (CON 3)
must remain connected to the board for accurate results. If
the load is not connected to the board, the DMM gives a
false reading.
To check power from the control board to the front or rear contactors
(energized), measure the voltage (120 VAC nominal) across the ter-
minals at the contactor. The exposed contactor terminalsor the capacitor
leads provide convenient hook-up points. For ease of access, the
solenoids mount on removable base plates. Remove the nut (Figure 5-3)
from the front end of the plate. Lift the front edge of the plate and slide it
toward the front. The rear base plate nut may need to be loosened to
allow the plate to slide freeiy.
To check power to the water flow solenoids, slide the connectors about
1/8-inch or less from the solenoid terminals. The connectors must remain
firmly attached to the solenoid terminals. Move the connector only
enough to allow the voltmeter probes to contact the metal solenoid
teminals. Measure the voltage (120 VAC nominal) across the terminals
of the energized solenoid. When measurements are completed, remem-
ber to slide the connectors fully onto the solenoid terminals. Replace the
base plate and secure with the front base plate nut.
Figure 5-3. Removable Base Plates
Water Fill Solenoid Valve
The water level control for the steam generator activates whenever the
steamer is on. During normal operation, the water fill solenoid energizes
(valve open) if the resistance between the water level probe and the
steam generator ground has been higher than the set point (12,000
Ohm) continuously for more than 5 seconds. This indicates that the
water level i
n the steam generator is below the flag welded to the tip of
the probe.
Printed 4/90