W973 Logic Panel

W973 solid state energy management systems control heating, cooling, and economizer operation in commercial air conditioning equipment. The logic panels are compact to fit easily in air conditioning equipment control panel. Panels can be used with staged gas, oil, or electric heat; modulating gas, hot water, or steam heat; and direct expansion or modulating chilled water cooling. The positive modulating low limit starts to close the economizer motor to minimum position if the discharge air temperature drops below factory-set temperature of 62 °F (17 °C). The motor will be at minimum position when discharge temperature is 50 °F (10 °C). W973 logic panels balance system output against space load demand to maintain stable room temperature with minimum temperature swing. The systems recycle to all stages off-on power interruption. When power is restored, the systems sequence stages back on with a time delay between stages.

• Integrated economizer provided as the first stage of cooling in all models
• Load reactive time delays provided ensure stable system performance
• 1/4 inch male quick-connect terminals provided for wiring connections
• Pilot duty SPDT relays control on-off heating and cooling stages
• Modulating DC current signal controls economizer and valve motors
• Solid state dual set point thermostat located in the controlled space provides heating and cooling input signals
• Up to six W973 panels can be controlled from one thermostat
• Secondary sensor located in discharge air duct provides anticipation and a positive economizer modulating low limit signal

• Canadian Standards Association: File No. LR95329-3
• Underwriters Laboratories, Inc: Component Recognized, File No. SA481