David Price, vice president of communications and corporate development at Camden Door Controls, is understandably proud of his company’s latest electric strike.
The CX-EPD1289L, released in September 2022, is the first surface-mounted rim strike that has preload mitigation built into it. That it would be the first of its kind is surprising to Price, however.
“The cart was kind of put in front of the horse on the preload [issue], because it’s not the mortise strikes that are the biggest problem,” he says. “Rim strikes actually have a much, much harder time with any pressure on the jaws of the keeper.”
That’s a Relief
Preload, or the pressure that builds up on a door and, thus, the locking mechanism, typically is more prevalent on exterior doors. When enough pressure is built up on a door, preload could cause binding between the latch and the strike keeper and result in the door failing to open electrically.
Preload has a number of causes, but the most common is operating HVAC systems. Because of a desire to control heating or cooling costs, buildings have become increasingly airtight, including the installation of weatherstripping around door gaps to keep cool air in when it’s hot outside (or vice versa during heating season). With no escape, the air puts pressure on the door. This typically isn’t a problem on interior doors, where, presumably, temperatures are constant on both sides of a door.
Another problem that typically produces preload pressure is misaligned door hardware. This can happen on any door, of course, particularly as it ages, but it’s a more typical problem on exterior doors, Price says.
“It’s a very common situation where a rim exit device on a door is not aligned properly, which means the locksmith is faced with having to reposition that rim exit device on the door,” he says. “We hear that all the time. So, these issues of preload actually apply much more to a rim [strike] than they do an ANSI strike.”
The CX-EPD1289L aims to rectify that in a couple of ways. The first is its design, which includes two independent cams. Solenoids working with the cams release the strike’s keeper after a request-to-exit switch is triggered, and it will do so even if up to 15 pounds of preload pressure is put on the strike.
It’s a patented design that Price says has been in development for three years.
“We always felt strongly about the design,” he explains. “But as we were going through it, we found that we needed to beef parts up, change the material that we’re using [and] change the actual physical design in some way so the strike would work flawlessly across the board.”
The second way is in the nature of its operation as a preload electric strike. Because it can operate with a substantial amount of preload pressure placed on it, Price says installation of the CX-EPD1289L doesn’t have to be as precise as it does for a standard electric strike, where even slight misalignment can result in preload and failure to open.
“The door doesn't have to be perfect; the crash bar doesn't have to be perfect; you have some flexibility in that,” Price says. “So, it makes installation better.”
Installation was an important consideration for Camden in the development of the CX-EDP1289L. In fact, the electric strike includes a metal marking template. All you have to do when installing the strike with, say, an exit device is line up the template with the latch, make your marks and drill the necessary holes. That’s the advantage of a surface-mounted strike, Price says.
“You don’t have to cut into the door frame, which is really huge,” he says. “You’re just drilling holes and bringing your wires in, so that’s much faster.”
Another feature of the CX-EDP1289L that should appeal to locksmiths is its “universal” design, he adds.
The stainless steel strike has field-selectable fail-safe or fail-secure operation and includes a removeable latch-monitoring switch. It also has dual 12- or 24-volt AC or DC power and nonhanded assembly. (Camden notes that AC operation will produce a buzz, while DC will be silent.)
The “universal” nature of that package means you don’t have to stock different models for different applications. The only available option for the CX-EDP1289L is a one-eighths-inch space plate for horizontal adjustment. That also means that every model comes with the same ANSI/BHMA Grade 1 rating and 3-hour UL fire rating (when in fail-secure mode).
But any discussion of benefits comes back to the strike’s preload capability, and Price suggests that it’s ultimately a time-saver for the locksmith and money-saver for the customer.
“If you have a rim strike that has no preload, you’re going to be sometime faced with having to go back to do a service call on that rim strike,” he says. “It won’t function after either the crash bar moves a little bit or the door itself becomes out of alignment. When you think of the cost of a service call, whatever it is, that’s much more money than the cost of the strike.”
The CX-EPD1289L is desinged for use on high-traffic perimeter doors in commercial, retail, institutional and multifamily-residential doors.
More info: www.camdencontrols.com