Electric Strike Installation GuideBy Brian Rhodes, Published Jan 20, 2015, 12:00am EST
Follow this guide and you will install a strike correctly everytime. As we detail in this post, installing electric strikes successfully is mostly good preparation, but when done right provides years of trouble-free use. We use our test door to walk through the practical installation steps needed to get it right. Even if you never will install a strike in your life, do you know if your doors are right enough? In this note, we walk through the steps needed to get it right, everytime.
The process of installing strikes correctly is not complicated, but care should be taken to perform each step:
- Door/Frame Alignment
- Strike Box/Jamb Prep
- Strike Prep
- Power Connections
- Final Checks
If all the steps are followed, installing strikes can take minutes and involve minimal troubleshooting. We cover the steps in detail below:
Making sure the door and frame is aligned is a critical pre-requisite. See our door / frame alignment tutorial for background.
From this point forward, the tutorial focuses on frame prep and strike installation on a non-fire rated opening. While the fundamentals of operation are the same, maintaining an opening's fire rating limits strike selection and frame modification to a degree not covered here.
Strike Box Preparation
The next step is to cut the frame so the strike fits. Even 'zero cutting' surface mount strikes used with surface hardware may require frame modification, and it's a sure step when using mortise mount strikes. We break down these steps into two parts depending on the frame:
- Factory Notched Frames
- Field Notched Frames
Factory Notched Frames: The scenario requiring the least amount of prep work is a door frame factory notched to work with a certain strike, as was the case with our door. However, even a factory notched requires filing down sharp edges and bending or adjusting mounting tabs so they do not interfere with the strike.
In our door, the strike pocket was slightly undersized so we had to use a file to enlarge the opening. When performing this step, test fitting the strike to the frame is helpful, with attention paid to potential spots where the frame touches the strike. Any pressure or tight fit can warp the strike or cause it to bind, and the strike should fit easily into the pocket.
Field Notched Frames: However, many frames are not factory built to work with strikes, and more drastic modifications are required. In many cases, the existing strike box (called a dust box) needs to be cut out to make room for the new strike. The strike's installation manual generally includes specific instructions to take when modifying the frame, and the needed cuts can be made with a high-speed rotary tool (like Dremel) for steel frames or with chisels for wood. The image below is a standard example of the prep dimensions:
A good instructional video on how to cut out a mortise strike into a wood frame can be found below:
After the frame has been readied, fine tuning the strike for install is next. That process follows these points:
- Fail Safe Configuration
- Trim Plate Installation (optional)
- Power Cabling
We cover these steps in the video below:
Fail Safe Adjustment: Many electric strikes are 'field adjustable' for either power failure condition. (For background, see our Fail Safe vs. Fail Secure Primer) Changing from one state to the other usually entails changing position of springs, solenoids, or even small levers. In the case of our strike, you must change the position of two small screws hidden under a label:
Most strike installations will use a 'fail secure' position regardless of where they are installed, and this is the default condition most are shipped with. We confirmed our strike was configured correctly, and left it as shipped.
'Trim Plate' Installation: For sloppy cutouts that may be unsightly or slightly oversized, most mortise strikes ship with an optional trim piece that hides the cutout. This trim, called an 'enhancer' or 'skirt' provides no security or operational benefit, just serves to cosmetically improve sloppy preparation work.
Power Cabling: Many strikes ship as 'Dual Voltage' compatible, meaning they operate given either 12 VDC or 24 VDC supplies. Some models include a dual voltage transformer in the housing with a single pigtail , while others are sold with two different pigtails trailing from the case. After confirming which supply voltage is available, the strike can be configured for use, typically involving twisting or jumping certain wire pairs together. The image below is the example wiring diagram for our strike:
At this point most of the work is complete and the payoff is close. There are just a few more check to make as the strike is finally installed into the frame:
- Faceplate Selection
- Power Connections
- Final Function Checks
These final steps are covered in the video below:
Faceplate Selection: Strikes generally ship with two or more faceplates, and selecting the correct one is critical during use. The 'keeper' area of the strike is bigger than the door lock's latches, and the faceplate narrows down the opening to match the specific type of door lock. This increases the 'tamper resistence' of the installation by eliminating potential gaps to insert prying tools behind the keeper.
Other door lock features, like the deadlatch, need a positive surface to rest on when the door is closed, and the faceplate provides this surface. Our strike was furnished with two options, and because it will be installed with a mortise lockset, we will use the 'mortise faceplate':
Power Connections: Power cabling for strikes should be 'run-to' rather than 'run-from' the strike. This means that the power cablings are most easily routed from the source (typically a controller), through the frame, down into the strike box. Especially when mortar shields are prepped into the frame, the actual opening to run cable out of the box is likely difficult to find. When using a fishtape or glowrods, they can be driven up and out of the frame, taped to the end of the cables, and the power leads are drawn down into the strike area.
Once the leads are in the box, they can be connected to the strike's pigtails. The image below shows our strike, which included a factory snap-style connector for both ends of the power splice:
Installation/Shimming: After power connections are made, the strike body should be inserted into the strike box, being careful not to pinch or crimp the cabling. If the prep beforehand has been done properly, this should be one of the easiest steps in the process:
The strike itself is not ready for use without sandwiching the faceplate down on top of the strike. At this point, with the faceplate seated onto the strike, it should be secured into the frame with the included screws or bolts. The strike itself should be square in the pocket, with no parts of the frame touching the strike except for the mounting tabs.
If the strike appears to be too far forward or too far back into the frame, or if it can be 'wiggled' in the enclosure, then shims should be installed to take up the slack. Most strikes include shims and designate their installation locations without causing interference to the strike's action. The aim of shimming the strike is to give it a solid mount with the frame, not compensate for alignment issues. If those conditions are noted, then we recommend checking the squareness of the frame and alignment of the door.
Final Function Checks: At this point, the installer should check the strike's alignment with lock. Visually confirming the latches of the door lock are enclosed by the keeper is key. If the door latches do not physically make contact with any part of the strike when the door is shut, then the strike has been properly installed.
The goal of the installation is a strike flush mounted to the frame with no backpressure on the door's latches. If these situations are noted, the should be corrected before calling the job finished.
Most of strike installation is unglorious and even rough, but doing the basic prep work is necessary for trouble-free use. If the installer does a thorough job on the 98% preparation work, then actually installing the strike is an easy 2% effort.
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