Exit Devices: Dogging Options
When we refer to dogging an exit device it means holding the latching mechanism retracted. There are several methods to “dog” an exit device, but they can be divided into two groups: Mechanical dogging and Electrified Dogging. The level of security that is wanted at the opening is one of the main factors to determine which method of dogging should be used. Fire ratings will limit dogging options.
There are several benefits to dogging an exit device. It allows the doors to be used as a push/pull operation which reduces the wear and tear on the exit device and lever trims. Dogging exit devices allows traffic to flow much easier, especially in high traffic areas.
Mechanical dogging is the most common way exit devices are supplied. The dogging mechanism is usually going to be installed internally somewhere along the body of the device. The mechanical dogging options include:
- Hex key dogging
- Cylinder dogging
For Hex key applications there will be a hole somewhere along the body of the exit device where the hex key can be inserted. While the push pad is depressed, turning the hex key will lock the dogging mechanism to hold the latchbolt retracted.
When an exit device is fire rated it cannot have mechanical dogging capability. This would prevent proper latching in the event of a fire.
One caution is advised when using hex key dogging: any matching hex key that fits in the exit device can be used to dog the exit device. In some instances (such as in schools) someone may be able to dog the device when you don’t want them to. In this case you may want to use cylinder dogging that requires the security of a cut key.
For Cylinder dogging there will be a cylinder installed where a key must be inserted. As the key is turned, the cam on the cylinder turns and engages the dogging mechanism to hold the latchbolt retracted. The cut key allows security personnel to be the only ones with the ability to dog the exit devices. A thumbturn cylinder can also be used if keyed cylinder security is not necessary.
Von Duprin offers a dogging kit that includes a security indicator showing if the door is dogged or not. This is helpful in emergency situations because it provides an immediate visual to security personnel letting them know if they need to un-dog the exit device so that it will latch.
Electrified exit devices can have dogging as part of the access control system. In this case, the exit device will need to be programed so that it can be dogged for a certain period of time. A schedule can even be set up so that the exit devices are automatically dogged during a certain time and will be released automatically when needed.
Electrified dogging on exit devices prevents the need for personnel to manually dog every single device, which can be time consuming if your building has many devices to be dogged such as schools, hospitals, or shopping centers. You can also be assured that all the exit devices are un-dogged and secure at closing time.
If an exit device is fire rated, it can be electrically dogged if it is tied into the fire alarm system and automatically releases upon receiving the fire alarm signal. This allows the exit device to be used as a push/pull device and still be able to latch in the event of a fire.
When dogging is not needed on an exit device you can request that the exit device be supplied “less dogging”. This removes the mechanism that holds the latchbolt retracted. On an electrified device, it needs to be programmed so that the access control system does not dog the exit device at any time.
When an exit device does not have the capability of dogging, be advised that there is likely a reason the device cannot be dogged. Any method used to hold the latchbolt retracted that are not part of the device’s typical functionality or mechanics is not recommended (i.e. duct taping the latchbolt so that it does not latch).
Life safety and other building codes may restrict when and where dogging can be used. Therefore the exit device should not be dogged in these circumstances. If there is any question the Authority Having Jurisdiction should be consulted.
Exit devices are available with the dogging option to allow for the convenience of push/pull operation. It can be accomplished in a few ways and at times it is restricted so be aware of the application and limitations that may be involved.
Many manufacturers, such as Von Duprin, offer kits that can convert existing exit devices from one style of dogging to another style. For example, an exit device that is currently capable of Hex key dogging can be modified so that it has Cylinder dogging to provide more security. Beacon Commercial Door & Lock can help you with these and many more exit device needs.
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