FAQ – dormakaba Door Closers for Fire Rated Glazed Doors

Variable power type door closers

1. In BS8300 it states that the door closer should be of a variable power type. Can a fixed size door closer be used on fire doors?

In general a fixed powered closer with a typical efficiency of 60-65% (BS EN1154 requires a minimum of 55% at EN3) would be unlikely to comply with the 30N opening force. Similarly, door closers with power adjustable only by template (selectable power) are not recommended.

However, very high efficiency fixed power closers such as the TS91 Cam Action Closer can comply with the required opening forces on certain door widths. A variable power closer however is a more flexible solution as it allows for
on-site adjustment to site conditions and can be adjusted to ensure minimal opening force.

2. BS8300 states that “in general” fire doors should be of
a width greater than 900mm. Why have dormakaba
offered solutions at lower widths?

We have based the solutions on the minimum requirements of BS8300/ADM*, starting with a typical 826mm wide door and have then gone up in
approximately 25mm increments. A number of dormakaba high efficient door closers are capable of coping with doors at these and smaller sizes.

3. BS8300 refers to electrically powered hold open
devices. Which suitable products are available from

electrically powered hold open devices

dormakaba offer the following electrically powered hold open door closers: ITS96 EMF, TS93 EMF, TS92 EMF, TS91 EMF and TS73 EMF. We also offer the BTS80 EMB floor spring (see above photo) and the RTS 80 EMB hold open
double-action transom closer.

Alternatively any dormakaba door closer can be used in conjunction with independent hold open magnets (EM). When using electrically powered hold open devices the door closing device is not required to comply with the opening force of less than 30N (when the electrical supply has been cut through activation of the alarm or power failure). However certain buildings may benefit from having electromagnetic devices that, when the power is removed, they still comply with the 30N maximum opening force. Here the use of Cam Action EMF Door Closers, or Cam Action Door Closers used with EM magnets will provide opening forces of 30N or less when fitted at size EN3 on door widths as detailed earlier.

4. BS8300 refers to “swing free” controlled door closing devices. Which suitable products are available from dormakaba?


“Swing free” door closers operate without the resistance of a door closer; the closer is only activated in the event of a fire or power failure making them most suitable for door access to individual rooms rather than part of a circulation route. dormakaba offer: TS99 FL and TS73 EMF Free Swing option, RTS80 FLB and BTS80 FLB floor spring.

5. BS8300 talks about lower power sizes for non-fire
resisting doors in comparison to fire doors using a door closer. What if a higher power size is required?


As there is no legal requirement for a minimum closing force on non-fire doors the door closer can be adjusted below size EN3 (18Nm, as required for fire doors). However the door closer should always be adjusted to successfully close the door. If this increases the force to exceed BS8300/ADM* requirements, for example to overcome heavy duty seals on an acoustic door, dormakaba can supply a supplement to an access statement detailing the measures taken to ensure opening forces have been kept to a minimum.

*Section 3 in Scotland, Part R in Northern Ireland

Force Graphic for Standard rack and pinion closers

6. BS8300 mentions avoiding door closers
where the maximum closing force is not between 0-15
degrees. What type of closers exhibit these properties?

BS8300 mentions avoiding door closers where the maximum closing force is not
between 0-15 degrees. What type of closers exhibit these properties?

Force Graphic for Cam Action closers

dormakaba’s unique cam action closer combined with a slide arm and channel do not experience an increase in the opening resistance but a rapid fall in opening resistance on operation of the door.

As opening and closing forces are directly proportional, Cam Action closers exert their maximum closing force between 0-15 degrees of final closure as required in the guidance to ensure the correct latching action.

7. Why should Cam Action closers be
preferred over standard rack and pinion closers?

Cam Action closers provide greater benefit to any user when operating a door fitted with a closing device. BS8300 and ADM requires the opening resistance to drop to 22.5N by 30 degrees, and although Rack and Pinion mechanisms with scissor arms can achieve this, a Cam Action mechanism achieves it far easier and much more quickly, resulting in easier access for all.

full opening backcheck facility

8. Can full opening of the door be achieved when using
the backcheck facility?

BS8300 details minimal resistance on a door when opened slowly. However this is only possible when using door closers with ‘thinking backcheck’. With ‘thinking backcheck’ as opposed to ‘fixed or standard backcheck’, the backcheck facility only engages fully when the door is opened with great force or speed, if the door is opened slowly then the backcheck will not engage. All dormakaba
overhead door closers with backcheck facility have ‘thinking backcheck’.

9. How important is regular maintenance?

BS8300 notes that without regular maintenance of all door fittings, the resistances to opening and closing can increase to an extent that the ability of disabled people to pass through the door can be affected therefore building owners and users must check doors regularly to ensure they meet the opening force requirements. Independent studies by PSA Research showed that where
doors and ironmongery represent as little as 1% of a building’s cost, they can account for 80% of the total maintenance bill in use. dormakaba Service division offer a full maintenance package for manual, automatic andindustrial doors.

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