Tech Tips: The Humble Keyswitch, The Sensible Keypad & The Mighty Maglock

Dec. 4, 2017

A client called with a big problem. The fire marshal made his annual inspection of the facility and took exception to two exterior gates on the premises which had electromagnetic locks and egress-only keyswitches. The maglocks were also connected to the fire alarm so power to them was cut when the fire alarm was activated.

These gates had operated like this for more than five years, and had not been cited previously. However, there was a different fire marshal each year.

The objection was that in an emergency where the fire alarm was not activated, there could be an extensive delay for a person with a key to get to the gate and open the gates.

These gates were on opposite ends of a fenced courtyard which was roughly the shape of a quadrant of a large circle with the building’s sides forming the two straight sides and a high chain link fence around the rest of the circumference. There were many alternate exit points from the three story, two winged building.

The fact that these gates were not cited previously is difficult to explain. Perhaps that they were previously overlooked, there were code revisions or this particular AHJ has his own point of view on areas of refuge and patient safety.

The immediate stated requirement was that the keyswitches were to be replaced with keypads like the ones which we had provided at virtually all patient accessible exits about four years ago when another AHJ threw the book at the facility’s management.

Actually the exits are equipped with a variety of solutions because there are many areas within the facility, and different levels of patient needs and healthcare staffing. There are numerous delayed egress doors, where patient elopements had occurred, injuries had resulted and actions by management were implemented.

Keyswitches are a bridge between mechanical keys and electric door control. A while back, keyswitches were used in alarm systems. The cylinder would mount on the door frame on the outside of the premises and would be used to shunt out the alarm to get through the door. Those were cylindrical keys in special keyswitch units. Cylindrical keys are still use for vending machines and other specialty applications. Most keyswitches these days use a “standard” mortise cylinder and the rotation of the tail piece on the cylinder actuates one or two microswitches.

Interest in keyswitches has declined. As is the case with my client’s door, using a key is less convenient as a keypad and low-end keys and cylinders are too easy to pick. Putting a keyway that is not restricted, or is not ‘high security’ is not recommended if there are any concerns about  security.

But for certain applications, keyswitches are appropriate. The contacts and switch functions for keyswitches are consistent with contacts and functions for other switching devices such as pushbuttons and relays.

Here is a description and explanation for the terms used to describe and identify them.

SINGLE GANG: A plate designed to fit on a single gang electrical box. The depth of the backbox may be an issue with certain keyswitches.

NARROW STILE: Used for narrow stile door mullions typically used on storefronts.

DOUBLE GANG: Aa plate designed to fit on a double gang electrical box. These are good for applications where you want to mount a keyswitch along with an annunciator, or visual indicators.

MOMENTARY: A switch contact which actuates for only as long as the key is turned, or the button is pressed, then returns immediately to it “Normal” state.

ALTERNATE ACTION (sometimes also referred to as toggle): These switches maintain the contact change indefinitely once they are actuated, until the next actuation. A typical l wall switch is an example of an alternate action switch. With a keyswitch, you may not be able to necessarily tell the state of the switch by the position of the key in the switch.

NORMALLY CLOSED: A contact which is ‘closed’ (conducting) in its normal state. Actuating a normally closed switch will momentarily “open” the circuit.

NORMALLY OPEN: A contact which is ‘open’ (not conducting) in its normal state. Actuating a normally open switch will momentarily “close” the circuit.

SPDT (also referred to as a form ‘C’ type contact): Single Pole Double Throw. This controls a single circuit and connects one of two poles depending on the state of the switch. A SPST (aka on-off) controls one circuit and is either on (conducting) or off (not conducting) This type of configuration is used for a simple on off light switch. Normally closed version is a type “B” (could be used to unlock a failsafe electric lock). Normally open version is a type “A” (could be used to control a failsecure type electric lock.)

DPDT: Two sets of SPDT contacts in a single housing controlled in tandem

Mortise Keyswitch: A keyswitch that utilizes a mortise cylinder

The Humber Keyswitch

Securitron has an extensive line of keyswitches. Shown in the job site picture is the Model MK. By using the normally open side of the SPDT switch, the LED on the faceplate can be controlled giving a handy illumination for when the switch is providing power to the electromagnetic lock and when the keyswitch is being actuated to unlock the electromagnetic lock. The single LED is referred to as bi-color; it has a wire lead for the red indication and another wire lead for the green indication Besides signaling the locked and unlocked status of the switch, the LED provides easy indication that there is voltage to the keyswitch.

MODEL MK features include:

  • Bi-color LED which can be field configured to operate at either 12 or 24 VDC
  • Backing bracket permits integration with any 1-1/4" [32mm] or 1-1/8" [28mm] mortise cylinder (not included).
  • Additionally the bracket will hold an additional microswitch for special applications which would  be activated by turning the key in the opposite direction
  • 5 Amp rated plunger switch
  • Includes anti-tamper screws
  • Cylinder available for use in the MK

    1-1/8" Length, 26D Finish

    SC Keyway

More Info:

The Sensible Keypad

ESSEX manufacturers a variety of versatile and rugged door control accessories. They are suitable for outdoors and harsh environments; they can be adapted to a wide variety of applications, and they can be configured so that end-users can usually reprogram them without problems.

The SKE-34 (3 X 4 style keypad) and SKE-26 (Narrow Mullion two rows of 6 buttons) are heavy duty self-contained access control keypads with many features that make them suitable for use in residential, institutional and harsh environments.

These devices have an integral Form C 2A main output relay, as well as two .25A open collector outputs which can operate exterior relays and be controlled in a variety of ways.

It may be configured to operate at 5 VDC or 12/24VDC.

The keyboard is laser etched Stainless steel piezio actuated with no moving parts, and weather/vandal resistant. They are available in several finishes. With accessories that include illuminated spy-proof rim and card reader interface, the unit can be adapted for relatively sophisticated door control operating as a standalone requiring only power and a lock to control.

This client observes a very good security practice. For most of the doors which have these keypads, they reprogram the code every month. With a moderate turnover of staff, and many outside contractors, changing the code makes perfect sense, and I have it set up so the client can reprogram the keypads without taking the keypad off the wall or using any tools. If (or more accurately for when) they mess up, I have given them a short write up on how to default the keypad and start over. They misplace it and I email copies.

I sold them spare units. This is all so they can undertake managing their doors by themselves and save emergency service calls, since if a keypad will not unlock a door, that door is disabled until the issue is resolved which might take a while. Of course they frequently mess up while reprogramming. Then they mess up while trying to default the keypad to the point where the keypad is blown, or cannot be revived by a civilian. So this is recurring revenue for me.

ESSEX SKE 34 & 26 self-contained access control features include:

  • 3 progammable outputs
  • Up to 500 user codes (plus master and temproary code)
  • Laser marked keypad graphics
  • Weatherproof -40c to +70c
  • Waterproof 100% relative humidity
  • Draws only 35Ma at idle
  • 1 billion cycle switch life
  • REX input
  • Anti-Tailgate feature
  • Door forced/AJAR alarm
  • Programmed at keypad, no computer or programmer required
  • Limited lifetime warranty
  • More Info:

The Mighty Maglock

The Securitron M680E SERIES is at the other end of the scale of security technology. Securitron made an electromagnetic lock with everything.

=M680E Product Features

  • 1200 lbs. Holding Force
  • Efficient, low power usage. The M680E with EcoMagTM technology from Securitron® delivers the same unsurpassed intelligence, style and convenience as the previous M680 series, but with up to 80% reduction in energy consumption.
  • Built-in door prop sensing allows the magnet to de-energize the coil when the door is held open for extended periods, dropping the power draw as low as 20mA at 12V.
  • Strike plate mounting template and bracket mounting for easy installation. This lock uses the same templates and mounting hardware as most of the Securitron line, so you can use existing tool kits and mounting accessories, the Innovative install templating  provides for effortlessly accurate alignment between magnet and armature plate
  • Patented BondSTAT lock bond sensor: Consistent with the trend towards remote management, the BondSTAT reports the security level of the lock and door. LED Indicator shows the lock is secure, open, or has an incomplete bond. LED visual locked status with configurable red/green color output are appreciated by security management who can easily visually assess the status of the maglock.
  • Testing the installation is possible performing the Calibration Button using the LED error codes for troubleshooting.
  • NO or NC configurable Tamper Switch sends an alarm output if the cover is removed.
  • No jumpers required to set voltage Autosensing dual voltage with microprocessor technology
  • Built-in Adjustable automatic relock timer (0 to 30 seconds)
  • Wire chamber anti-tamper switch
  • Size optimized for use with door closers allowing room for the maglock AND the closer.
  • MagnaCare® lifetime replacement, no fault warranty

Product Options:

M680EBD: Built-in smart voltage sensing microprocessor controls Securitron’s integrated patented BondSTAT, tamper sensor as well as door position status monitoring.

M680EBDX: Everything included in the M680EBD model plus integrated request to exit (REX) provides optimum coverage for detecting an approaching person so the door unlocks for egress.

M680EBDCX: Everything included in the M680EBDX model plus optimal coverage with the integrated passive infrared (PIR) request to exit (REX) and analog CCTV camera that allows for video surveillance.

More Info:

About the Author

Tim O'Leary

Tim O'Leary is a security consultant, trainer and technician who has also been writing articles on all areas of locksmithing & physical security for many years.