Installation / Operation Instruction Manual

19
Servicing Guide continued-
Optional Components
High and Low Water Pressure Controls
These controls interrupt the electrical current to the contactor coil when the
pressure settings are exceeded. The operation and setting of these controls
are described in the manual provided by the control manufacturer. This
manual is included with the water heater Installation and Operating
Instruction manual provided by the manufacturer.
The pressure settings for these controls are adjustable. These controls are
specified for use when the install
ation has unique pressure requirements that
must be safeguarded. Therefore, before adjusting the pressure values, it is
recommended that you consult the person responsible for the facility that the
water heater is servicing.
The electrical connections are referenced in the Control Circuit Wiring
Diagram and in the pressure control manual provided by the control
manufacturer. Refer to these instructions when servicing the controls.
The following unusual situations will give reason for the pressure controls to
int
errupt the electrical current to the coil of the contactor:
 Upon installation or occasions of re-starting heater operation, if the
inlet supply line is closed (i.e. a shut-off valve), the high pressure limit
may be exceeded due to reasons of thermal expansion of the water.
 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 during the operation of the water heater t
he 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.
Low Water Level Control
This control will interrupt the electrical current to the contactor coil when a low
water level condition is sensed inside the water heater tank. When the low
water level condition is corrected the control will automatically sense the new
situation and electrical current will again energize the contactor coil. Normal
water heater operation will be resumed.
To remove the low water level control from the tank you must first loosen the
control by un-threading it from the tank fitting and then rotating the control
until the arrow printed on the side of the hex fitting is pointing downward.
Refer to Figure 6 for clarification. This will enable the float orientation to align
itself with the opening in the tank-fitting.