1640-1

1640-1 is a series 1640 floating contact null switch for high and low actuation. The Dwyer® Model 1640 differential pressure switch resembles the high precision large diaphragm series 1630 switches. However, the Model 1640 is equipped with a single pole, double throw floating contact switch (not snap acting) so it functions as a null switch. As the diaphragm moves in response to pressure changes, it moves the floating contact to cause switching action at two pre-set points with no switching action between these points. The “high” circuit will be closed when rising pressure differential reaches the pre-set level. The “low” circuit will be closed when falling pressure differential reaches the pre-set level. Typical applications include damper positioning and duct air control.

• Range 0.2-1.0" w.c.
• Adjustable null span, minimum set point is .02, maximum set point is .06
• Floating null switch supports applications requiring 2 set point actions(open, close damper control)
• Visible set point indicator simplifies operation and trouble shooting
• Large diaphragm provides low range accuracy providing precise control
• Temperature limit range from -30 to 110°F (-34.4 to 43.3°C)
• Pressure limit of 10psig (68.95kPa) continuous, 25psig (172.4kPa) surge
• 3 screw type electrical connection
• 1/8" female NPT process connection
• Diaphragm in vertical position