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Cold Weather Modulator

Using a vacuum pump with gauge, apply 16 in. Hg of vacuum to motor side of modulator. Determine if modulator holds or leaks within the correct temperature range. See COLD WEATHER MODULATOR SPECIFICATIONS table.

COLD WEATHER MODULATOR SPECIFICATIONS

Modulator Color Holds Vacuum @ °F (°C) Leaks Vacuum @ °F (°C)
Black/Normally Open 20 (-6.7°C) 35 (2)
Blue/Normally Open 40 (4) 55 (13)
Green/Normally Open 50 (10) 76 (24)
Yellow/Normally Closed 65 (18) 50 (10)