A. Basic Temperature Control Module At the centre of the System 350, the A350 temperature control has remote sensing capability up to 800 feet. Sensor #SET189A-600R is included for immersion, outdoor air, room temperature and duct applications. The A350 controls the temperature to with in +/- 1°F. A heat/cool switch makes it easy to field select either the heating or cooling mode of operation. The A350 is powered by 24VAC and features a wide differential range that can be adjusted from 1°F to 30°F. Temperature range: -30°F to +130°F. SPDT enclosed relay. Contacts rated at 10 amp, 1/2 HP, 120/240VAC. Temperature Module 2.4" x 2.4" x 5"