Installation / Operation Instruction Manual

23
Servicing Guide continued-
The following unusual situations will give reason for the alarm to sound:
 If a High Pressure Control is installed, upon installation of the water
heater or occasions of re-starting water heater operation, if the inlet
supply line is closed (i.e. a shut-off valve), the high pressure may be
exceeded due to reasons of thermal expansion of the water.
 If a Low Pressure Control is installed and if during the operation of
the water heater the inlet line is closed (i.e. a shut-off valve), a low
pressure condition can develop when water is allowed to exit
through the outlet connection.
 If a Low Pressure Control is installed and if during the operation of
the water heater the inlet line is closed (i.e. a shut-off valve), a low
pressure condition can develop when water is removed through the
water heater drain valve.
Heating Element Sequencers:
Heating element sequencers are available in order to stage the activation of
the heating elements thereby, reducing the inrush current to the water
heater. The sequencers will control one or two contactor coils depending
upon the water heater voltage, phase, and KW.
One contactor will be energized immediately when there is heating demand,
the second contactor, controlled with a sequencer, will be activated
approximately 20 seconds later, and the third contactor will be activated in
another 20 seconds thereby, staging the three contactors over the 40
second time period. The staging occurs in a similar manner for applications
having more than three contactors.
Refer to the Control Circuit Wiring Diagram for the specific application being
serviced.
Note: On the occasion of servicing the water heater where frequent restarts
in a short time interval are encountered (i.e. on, off, on, etc.), the timing
sequences will not begin until the sequencers have experienced a time
interval to reset.