Honeywell 940
Magnetic Door Contact and Window Contact
Description
The Honeywell 940 is a magnetic door contact and window contact that can be used with any wired alarm control panel. The 940 contact used to be available in (2) colors, but Honeywell discontinued the 940BR brown contacts so you can only get the 940WH white contacts.
The 940 is a surface mount magnetic contact that you can use to protect your home’s door and windows. You can even use the 940 contact to protect other openings like a liquor cabinet or an office drawer with important documents inside. When the magnet is close to the contact, the alarm control panel is in a normal, ready to arm state. When you open the door or window protected by a 940 contact while your security system is armed, an alarm will be triggered. You will not be able to arm your alarm control panel if you have open windows or doors. Your alarm keypads will display a fault when any of your 940 contacts are separated from their magnet.
The Honeywell 940 contact is very small so it is ideal for homes or offices where decor is a concern. The aesthetically pleasing cover even hides all unsightly mounting screws and terminals screws. Each 940 includes spacers and mounting screws to go along with the contact and magnet. You can use adhesive tape or the mounting screws to secure the contact and magnet to your door or window. The spacers are used for unusual door and window frames so that you can get the contact flush with the magnet when the door or window is closed. The magnet gap is 3/4” so you must ensure that the contact is within 3/4” of the magnet when the door or window is closed. The 940 contact uses a Form A, SPST, normally closed internal reed switch that has a rating of 100mA at 28VDC. If you choose to use an end-of-line resistor (EOLR) to supervise your contact loop, you can install the EOLR under the cover of the 940 contact or you can put it at the wired zone within the alarm control panel.
The 940 is super small. The exact dimensions are 1.52 inches in length by 0.53 inches in width by 0.47 inches in height.
Brand: Honeywell
Honeywell 940 Compatible Products
Reviews
Submitted on 09/23/2020 Alarm Grid
The Honeywell 940 is a popular hardwired door and window contact sensor. This sensor has stood the test of time due to its simplicity and effectiveness. It is a very simple door and window contact that does pretty much exactly what you would expect. The magnet goes on the moving portion of the door or window, while the sensor goes on the door or window frame. Opening the door or window causes the magnet to separate from the sensor, which triggers and alert on the security system. We think that the Honeywell 940 is a great sensor, and we give it a perfect 5-Star score.
Sometimes the best sensors are the ones that are the most straightforward. And that is clearly the case with the Honeywell 940. It is a very compact sensor, which means that you are unlikely to notice it on the door or window. It allows for a surprisingly large magnet spacing gap of 3/4", which is 50% larger than the standard 1/2" gap that most door and window sensors provide. The necessary mounting hardware for the sensor comes included, so you will have no trouble getting started with the Honeywell 940. We also like the fact that a cover hides the resistor for the resistor. This helps to maintain aesthetics.
The downsides for the Honeywell 940 are pretty standard. As a hardwired door and window sensor, you will need to run a wire from the panel to the sensor. This may be a bit tricky if you are not used to wiring. But that comes with the territory when setting up a wired alarm system. The fact that this sensor is Form A could be considered a small downside, as it will not allow Normally Open (NO) wiring. But really, these downsides are extremely minor, and honestly, they are to be expected from a basic wired door and window sensor like the Honeywell 940. This simple and effective sensor will serve your home or business quite well for a very long time. It gets a well-deserved 5-Star rating from Alarm Grid.
Good: Compact, 3/4" Magnet Spacing Gap, Mounting Hardware Included, Cover for Resistor
Bad: Requires Wiring, Form A
Bottom Line: 5 Stars
