Hayward HeatPro Heat Pro Owners Operations & Parts Manual - Page 7

Page 7 of 22 HEATPRO HEAT PUMP High / Low Refrigerant Pressure Switches HP13023772 Rev: D • The high-pressure switch senses the refrigerant pressure in the sealed refrigeration system and turns the heat pump off if the operating pressure exceeds the acceptable range. The heat pump will automatically reset the switch after the system pressure returns to normal operating conditions. The display will show "HI", if this switch is tripped. • The low-pressure switch senses the refrigerant pressure in the sealed refrigeration system to protect against certain conditions that could be detrimental to compressor life. The switch turns the heat pump off in the event of loss of refrigerant, fan motor failure, evaporator freeze-up, or airflow blockage. The heat pump will automatically reset the switch after the system pressure returns to normal operating conditions. The display will show "LP", if this switch is tripped. Water Pressure Switch Adequate water flow through the heat pump causes the Water Pressure Switch contacts to close. Insufficient water pressure will allow these contacts to open, and turn the heat pump off. The display will read "PS" if the water pressure is not sufficient. Time Delay All models use a 5-minute time delay. Any interruptions, outside of power loss, will result in a 5-minute time delay. Low Ambient Temperature If the air outside the heat pump is too cold, the heat pump will not operate. The actual point at which the unit will cease operating due to low temperature varies. Current weather conditions, the amount of sunlight reaching the heat pump, and the installation quality are primary contributors to this event. The shutdown will occur near 50°F (10°C). This is not a "fixed" range. Low outside air temperatures will activate the systems defrost function by lowering the evaporator's outlet temperature. The fan motor will operate independently for 15 minutes in attempts to raise the evaporator coil temperature, at which time the heat pump's control system will check the temperature to see if the coil has warmed up sufficiently to return to normal operation. The control system will run through three 15 minute cycles checking the coil temperature. In the event that the coil does not return to normal operating temperature following the three 15 minute cycles, the heat pump's control system will shut the unit down completely for 2 hours (display will show "dEF"). After the 2-hour period, the unit will restart to check the evaporator temperature and try to resume normal operation. The heat pump control will continue this cycle until the evaporator temperature returns to normal. USE ONLY HAYWARD GENUINE REPLACEMENT PARTS Pomona, CA Clemmons, NC Nashville, TN Tel: 908.351.5400 www.haywardpool.com