Perhaps the best way to protect overhead door contacts from industrial motorized traffic like forklifts and large trucks is to recess or bury them into the concrete floor, allowing vehicles of this type to safely pass over them totally unaffected.
The G.R.I. 4510 switch series has been designed from the ground up, so to speak, for just such an application. The 4510 series features all stainless steel construction for maximum resistance to corrosion and has a wide working gap for those loose or badly worn overhead doors.
Name : GRI 4510AU Concrete Concealed Switch, 3 1/2" Gap, Open/Closed Loop, SPDT, C Reed Form, 5W , George Risk Industries
Category : Magnetic Contacts
UPC Code : 697625040841
Country of Origin : United States. Country of origin is subject to change.
ADI Part Number : GI-4510AU
Brand Name : GRI
Manufacturer : George Risk Industries
Manufacturer Part Number : 4510AU
Product Model : 4510AU
Product Name : 4510AU Magnetic Contact
Product Series : 4510
Product Type : Magnetic Contact
Product Material : Stainless Steel
Limited Warranty : Lifetime
Additional Information : <ul><li>Switch Protected From Heavy Equipment</li><li>Maximum Switching Voltage:175VDC</li><li>Maximum Switching Current:0.250A</li><li>Maximum Contact Rating: 5W</li><li>Electrical Configuration: N/O</li><li>Concrete concealed</li><li>S.P.D.T.</li></ul>
Country of Origin : United States
Package Contents : <ul><li>4510AU Magnetic Contact</li><li>Mounting Hardware</li></ul>