Basic Operation

19

 

 

 

SAFETY CONTROLS

AIR PRESSURE (FAN) SWITCH

The air pressure switch is a safety device used to insure that the blower (fan) is operating and has been designed to monitor the vacuum (negative) pressure within the blower housing. The air pressures switch is factory set and is in the ignition module circuit—the ignition module does not operate unless the air pressure switch and all safety switches are closed.

Figure 18.

AIR PRESSURE SWITCH

 

WATER PRESSURE SWITCH

The water pressure safety switch closes when there is a sufficient flow of water to the heat exchanger to safely operate the heater. The switch operation must be verified during initial operation of the heater after installation— the switch is set at 1 PSIG and the switch contacts must not be closed in the absence of water flow. NOTE: See, Below Pool Level Installation instructions on page 11. The switch may remain closed with no water flow if there is more than a 3 feet elevation difference between the heater (heat exchanger) and the pool water line— if this is the case, the water pressure switch must be reset to maintain open switch contacts with no water flow.

NOTE

If the pool is more than one floor above or one floor below the heater, the pressure switch may have to be replaced with a flow switch.

Figure 19.

Adjustment Knob

Typical Water Pressure Switch

Rev. A 1-2-02

P/N 472032

Page 19
Image 19
Pentair NT Standard Series installation manual Safety Controls, AIR Pressure FAN Switch, Typical Water Pressure Switch