Electrifying an Aluminum Store Front Opening
Aluminum Storefront Doors and Frames
Aluminum doors and frame are used in many commercial applications. Usually they are exterior doors, but sometimes they are used in interior spaces as well. They are made of aluminum tubing and glass. Often these doors are ordered "standard" from the manufacturer. Ordered this way, they often come with an Adams Rite MS deadbolt (shown at right), otherwise known as a flip bolt because the 1-1/2 inch bolt flips up out of the lock body into a slot on the aluminum frame. This is a very secure lock, but difficult to electrify.
Electrification of an aluminum storefront door therefore often entails working around this lock or replacing it. This article will deal with this and other issues surrounding electric locking of aluminum storefront doors.
Aluminum storefront doors come in narrow stile, medium stile, and wide stile varieties. "Stile" refers to the piece of aluminum tubing into which the lock is installed. This tubing is usually 1-3/4 inches thick. Narrow, medium, and wide refer to the width of the tubing. Narrow stile is usually 1-3/4 to 2 inches wide; medium stile is usually around 3-1/2 inches wide; and wide stile is usually about 5 inches wide. Before you proceed with electrification you should know what stile width you have.
The Latch and the Paddle
The Paddle and the Strike
In the old days, the only ways to electrify an aluminum storefront were to replace the MS deadbolt with an Adams Rite latch, or install the latch in another location and keep the deadbolt, and cut an electric strike into the frame. These are still often the best and/or cheapest options.
It is possible to release the MS1850S deadbolt with an electric strike, but it is inadvisable because it creates egress and other problems.
To replace the MS deadbolt with a latch, you need to know the backset. The backset is the distance from the edge of the door to the centerline of the cylinder hole. An MS deadbolt will have a backset of 31/32 of an inch, 1-1/8 inches, 1-1/2 inches, or very rarely 7/8 of an inch.
You will also need to know the door thickness, the finish, the stile width, and whether it is a single or one of a pair of doors. Pairs of aluminum doors usually are radiused - that is, they each have a rounded edge where they meet. Radius face aluminum pairs of doors require locks and electric strikes with radius faceplates.
The Adams Rite 4900 deadlatch is designed to be installed in the same prep as the MS1850S. The Adams Rite 4591 paddle will interface perfectly with the inner cylinder hole that was cut for the MS1850S (provided you selected the right backset latch). If you like, you can reuse the cylinder that came with the MS1850S and keep the same key. All in all, the lock side of converting the MS deadbolt to a latch is no problem.
The strike side is a different story. The illustration below shows the door frame on the left prepared with the slot to accept the MS1850S deadbolt and the door frame on the right with the same prep with the electric strike cutout overlaid. As you see, there is a lot of cutting to do.
Electric Strike Preparation
The electric strike cutout shown above is for the Adams Rite 7130 series electric strike or similar with 6-7/8 inch faceplate. Since the latch of the 4900 is above the bolt of the MS1850, the strike installation must be offset upward as shown. That is why a faceplate at least 6-7/8 inches long is necessary.
In many cases it is necessary to retrofit an electric strike to an existing Adams Rite latch. The normal strike used with Adams Rite latches is a two-hole strike like the 4901. If that is the case, the Adams Rite FPK45-628 faceplate kit with an Adams 7100 series electric strike body requires minimal retrofit cutting, or you can use the Trine 3458 electric strike to fit the cutout exactly with a very minor amount of cutting.
Several manufacturers - Major and Keedex, to name two - offer installation router templates to aid in making cutouts in aluminum doors and frames.
Electrified Latch Options
An alternative to the classic approach discussed above is the Adams Rite 4300 Series electric latch lock. While significantly more expensive than the classic, installation is much easier, saving valuable labor and time. My experience with the Adams Rite 4200 is that it is a reliable alternative. It works with the same paddle and cylinder as the Adams Rite 4510, 4710, and 4900 series latches.
Many technicians opt to use an electromagnetic lock, sometimes called a maglock. Maglocks are easy to install, simple, and not very expensive. The disadvantages to an electromagnetic lock are:
- They are inherently fail safe. When the power goes out and the battery backup runs out, they are unlocked.
- They are usually installed at the top of the door. Since only the top is locked, the bottom tends to pull out a bit when someone tries the door, giving it an insecure, sloppy feel.
- Maglocks lock people in as well as out. That's why some inspectors hate maglocks. Special care must be taken so that the means of egress not only satifies local, state, and national code, but the local Authority Having Jurisdiction as well.
Click here to read my Basic Maglock System article.
Electrified Exit Devices / Panic Hardware
If you have an aluminum storefront door with an exit device on it, you may be able to replace it easily with a compatible model with electric latch retraction, or retrofit an electric latch retraction kit to your existing device. These are very good options since they preserve the functionality that the opening was designed to have. Here is a partial list of devices that have drop-in replacements with latch retraction or retrofit kits:
- Adams Rite - drop-in replacements
- Corbin - drop-in replacements
- Doromatic - some drop-in replacements, some retrofit kits
- Jackson - drop in replacements
- Sargent - some retrofit kits, some drop-in replacements
- Von Duprin - some retrofit kits
Instead of electric latch retraction, you can also get electrified outside trim. The advantages of electrified trim over electric latch retraction are low current draw and ease of installation. Electric latch retruaction devices often require special power supplies because of their excessive inrush current which often runs 12 amps to 16 amps at 24 volts DC depending on the manufacturer.
One notable narrow stile aluminum door exit device is the Adams Rite 8800EL series, which requires less than 1 amp at 24 volts DC. It is relatively inexpensive and installs in minutes, particularly if the applicaton does not require an emergency key override. On single doors, this exit device is a very good alternative to an electric strike when dealing with an Adams Rite MS1850S in a retrofit situation. In most cases you can just keep the MS lock and add the exit device.
Pairs of Doors
Existing pairs of aluminum doors can be challenging to electrify unless you have concealed vertical rod exit devices that can be retrofitted for electrification. If you have an MS1850S Adams Rite deadbolt on one side and flush bolts on the other, the architect's intent was most likely to have both the deadbolt and the flush bolts unlocked while the building is occupied. If we were to use the flush bolts to make the affected leaf the inactive leaf so that we could install an electric strike in it and a latch in the active leaf, we would effectively change the double opening to a single opening. A fire marshall might not like that. In such a case, we can install a double electromagnetic lock and deal with the egress and security concerns inherent with it, or we can install surface vertical rod exit devices with electric latch retraction or electrifiend trim. Surface vertical rod devices are problematic because the exposed rods take a beating, and then they don't work right.
If there are concealed vertical rod devices for which there are no retrofit electrification kits available, it is possible to release them with an electric strike. The result, however, is a door that does not feel securely locked even if it is. Between the wiggle-room in the electric strike and the fact that only the top of the door is locked, a person trying the door might be able to pull the bottom of the door out 6 or 8 inches. Not a good result.
Please feel free to contact me to answer any questions you might have at:
Aluminum doors and frames are made by many manufacturers. When installing retrofit hardware, be prepared for surprises. Sometimes there will be an extra rib inside the frame, taking up space where the electric strike would go. When installing an electromagnetic lock, watch out for aluminum doors that are held together with a threaded rod inside the horizontal top rail, right where the sex nut for the mag lock armature should go. It is best to be observant and go slowly and carefully.