Cleveland SteamCraft V, Service Manual

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CET-16 Service Manual Page 65
circuit. The nominal set point resistance for all water level probe func-
tions is 12,000 ohms. Because the measured resistance includes both
AC and DC components, the measured resistance through water (probe
to tank) may be higher than the set point resistance. The measured
resistance may be as high as 17,000 ohms without significant effect on
performance.
Flood Probe Control Circuit
Water Level Probe Control Circuit
1. Shut off water supply fines and drain the steam generator.
2. Refer to the wiring diagram (see Table 6-1). Disconnect the blue wire
from the water level probe (probe nearest front).
3. Using a meter, set the resistance of the potentiometer to 20,000
Ohms.
4. With the probe disconnected, connect the potentiometer between the
common (green) wire and the blue wire that leads back to CON 2 (see
Figure 5-7).
5. Turn on the unit by pressing the POWER touch pad and begin timing.
The water fin solenoid should energize in 5 to 8 seconds.
Printed 4/90
Water Level Control Testing
To test the operation of water level sensing functions, use a multimeter
or ohmmeter and a 100,000 ohm potentiometer to check resistance.
Refer to test procedures below for function to be tested.
1. Refer to the wiring diagram (see Table 6-1). Disconnect the red wire
from the flood probe (small probe near top center of tank).
2. Using the meter, set the resistance of the potentiometer to 20,000
Ohms.
3. Refer to Figure 5-6. With the probe disconnected, connect the poten-
tiometer between the common (green) wire and red wire that leads
back to CON 2.
4. Turn on unit by pressing the POWER touch pad. The ON indicator
will light.
5. Allow 1 minute of operation for the flood shut down circuit to enable.
6. Remove potentiometer and change resistance to 5,000 ohms.
7. Reconnect the potentiometer. If the circuit is functioning properly:
• The FLOOD alarm light will begin to flash after 3 to 5 seconds.
• The POWER on/off touch pad will not function.
8. Remove the potentiometer and reconnect the probe. This will not
restore the unit to normal operation. Remove all power from the
steamer at the disconnect switch and then re-energize to reset the
FLOOD circuit for operation.
Figure 5-6. Flood Probe Test Connection