CleaverBrooks WB, Owner'S Operation And Maintenance Manual

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Operating Instructions
4-2 750-136
Model WB Electric Boiler Manual
FIGURE 4-1.
Temperature Controls
4.
Close the main power switch. Turn the pilot switch on to energize the boiler control circuit. The white pilot
light will light. If both temperature and water level are within limits, the red pilot light or lights will not light
and you will hear the contactors begin to close.
5.
To assure all limit circuits are operational, individually test each high temperature limit control by lowering its
setting momentarily. All contactors should drop out and the red “high temp” light should light. Then return the
setting to the desired limit setting.
6.
Monitor the temperature rise through the boiler. If a bypass piping arrangement is used, adjust the flow
through the boiler to obtain the desired temperature rise detailed in Chapter 3.
7.
Monitor the boiler operation to see that the control functions at the desired temperature setting. If the control
cycles on and off on the proportional type controller, widen the proportional range (about 5º at a time) until
the system is stable.
8.
If the contactors cycle too rapidly even after increasing the proportional band, the step control may have to be
adjusted to increase span, proportional band, or time delay, depending on the step control supplied.
Proportional Control On/Off Control