Dwyer Photohelic (Magnehelic) Pressure Switch/Gage A3000-0-TP-24V
Item Description, Features, and Specifications
This is a new in the unopened box (one box opened for photos only...), Dwyer Photohelic (Magnehelic) Pressure Switch/Gage model A3000-0-TP-24V.
The range on this model is 0~0.5 inches of water.
According to Dwyer...
Photohelic Switch/Gages function as versatile, highly repeatable pressure switches combined with a precise pressure gage employing the time-proven Magnehelic gage design.
The Photohelic switch/gage measures and controls positive, negative or differential pressures of air and compatible gases.
Two phototransistor actuated, DPDT relays are included for low/high limit control. Easy to adjust setpoint indicators are controlled by knobs located on the gage face. Individual setpoint deadband is one pointer width - less than 1% of full scale.
Setpoints can be interlocked to provide variable deadband - ideal for control of fans, dampers, etc. Gage reading is continuous and unaffected by switch operation, even during loss of electrical power.
Photohelic Sensing - How It Works
In typical applications, these Dwyer switch/gages control between high and low pressure set points. When pressure changes, reaching either set point pressure, the infrared light to the limiting phototransistor is cut off by the helix-driven light shutter.
The resulting phototransistor signal is electronically amplified to actuate its DPDT slave relay and switching occurs. Dead band between make and break is 1% of full scale or less - just enough to assure positive, chatter-free operation.
Range: 0~0.5" water column
Supply Voltage: 24v DC
Specs for the Series 3000 switches here.
Surplus, new in the box
Item is sold "as is"
No testing done
You will Receive:
(1) Dwyer Photohelic (Magnehelic) Pressure Switch/Gage A3000-0-TP-24V
Item weight is approximately 4.4 pounds.