Honeywell 951WG Recessed Magnetic Contact – White

3/8″ Diameter Miniature Press Fit Magnetic Contact

• With a 3/4″ long magnet, the 951WG is ideal for double-hung windows, casement windows, sliding windows, doors and other thin frame applications
• Standard gap: 1-1/4″– the largest gap of any mini 3/8″ contact
• 12″ leads are standard
• Normally Closed (NC) when the reed relay is aligned with magnet

Specifications:

Switch Type: Form A (SPST) Reed
Contact Rating: 300ma @ 30VDC

This recessed contact will work with any brand panel with a “wired” zone.  Perfect for windows or doors where wiring is not an issue (especially during pre-drywall construction). Since the contact is recessed the device is completely hidden when the door or window is in the closed position which is why they are so popular.  When the entry is open, only the small 3/8″ top of the magnet and reed switch is visible and you can choose white or brown colors to minimize that visibility even further.

Installation example:  Finished home the (typical case where the walls are already up and painted or wallpapered) where you want to install a concealed magnetic contact in a first floor double-hung window where there is an unfinished basement or crawlspace or accessible ceiling in a finished basement.

We suggest purchasing a long drill bit such as the Klein Tools 3/8″ x 72″ flex auger bit available at stores such as Home Depot as well as a simple stud finder.  First decide where the magnet (sash side) and reed relay (sill side) will be installed in the window frame.   Since you will be fishing the wiring through the wall below the window into your basement/crawlspace its important to make sure the location you choose is not aligned with a stud in the wall below the window frame.  TIP:  Use a stud finder to make sure you are not lined up with a stud holding the window up!  If so slide over a few inches and double-check to make sure you will really be drilling into a hollow space.

Next drill a 1″ deep, 3/8″ wide hole for the magnet that goes into the bottom of the window sash.  While the magnet will slide in after a few slight hammer taps and hold snug we recommend adding a little Elmer’s Glue to the magnet barrel to make sure it never comes loose as the wood expands and contracts over time.

Before securing the magnet into the sash however, slide a pencil (point stick out of the hole) and slowly close the window marking the spot on the bottom sill which perfectly lines up with the location of the magnet when the window is closed.  This is where the reed relay (the part with the wires) will be installed.  Drill a 3/8″ hole deep enough to break through the window frame itself and into the hollow in the wall (between the window and floor).  Next slide the 72″ long bit into the 3/8″ hole in the sill and let it drop to the floor plate.  Attach your drill and slowly advance until breaking through the floor into the basement.  Make sure there are no wires, pipes etc. in the basement ceiling that could be damaged when drilling through.

There is usually a small fish hole on the end of the auger bit to pull wire up from the basement and through the sill hole above.  If not tape wire to the other end (drill end) of the bit and pull the bit and wire down to the basement instead.  Attach the contact leads to the wire you just fished through the wall and push securely into the sill.  Again, recommend using glue to make sure the relay (and/or magnet) doesn’t come loose over time.

NOTE: The above example works well for securing the bottom sash of a double-hung window but NOT the upper sash.  This is where a wireless transmitter placed on the top of the bottom sash aligned with a surface magnet placed on the bottom of the top sash really shines.  Protection for both openings!  The downside is higher cost and possible aesthetics issues, but its a five minute install.