3.4.6.15. Door Release Hardware (1) Except for dwelling units, and except for devices on doors serving a contained use area or an impeded egress zone designed to be released in conformance with Article 3.3.1.12., and except as permitted by Sentence (4), locking, latching and other fastening devices on every exit door shall permit the door to be readily opened from the inside with not more than one releasing operation and without requiring keys, special devices or specialized knowledge of the door opening mechanism. (2) If a door is equipped with a latching mechanism, a device that will release the latch and allow the door to swing wide open when a force of not more than 90 N is applied to the device in the direction of travel to the exit shall be installed on (a) every exit door from a floor area containing an assembly occupancy having an occupant load more than 100, (b) every door leading to an exit lobby from an exit stair shaft, and every exterior door leading from an exit stair shaft in a building having an occupant load more than 100, and (c) every exit door from a floor area containing a high hazard industrial occupancy. (3) Except as required by Sentence 3.8.3.3.(7), every exit door shall be designed and installed so that, when the latch is released, the door will open under a force of not more than 90 N, applied at the knob or other latch releasing device. (4) Electromagnetic locks that do not incorporate latches, pins or other similar devices to keep the door in the closed position are permitted to be installed on exit doors other than doors described in Sentence (5) provided (a) the building is equipped with a fire alarm system conforming to Subsection 3.2.4., (b) the locking device, and all similar devices in the access to exit leading to the exit door, are installed as ancillary devices to the fire alarm system and release immediately upon activation of (i) the alarm signal where a single stage fire alarm system is installed, (ii) except as provided in Subclause (iii), the alert signal where a 2 stage fire alarm system is installed, or (iii) the alarm signal of a 2 stage fire alarm system installed in a care or detention occupancy, (c) the locking device releases immediately upon loss of power to the fire alarm control panel or loss of power controlling the electromagnetic locking mechanism and its associated auxiliary controls, (d) the locking device releases immediately upon actuation of a manually operated switch readily accessible only to authorized personnel and located near the main entrance of the building or in the central alarm and control facility of Sentence 3.2.6.12.(1), (e) the locking device releases immediately upon a fault being detected in the electrical circuit between the fire alarm control panel and the controller of the locking device, (f) the locking device releases immediately upon the operation of a manual pull station for the fire alarm system located on the wall not more than 600 mm from the door, (g) a legible sign having the words EMERGENCY EXIT UNLOCKED BY FIRE ALARM is permanently mounted on the door, (h) the lettering on the sign required in Clause (g) is at least 25 mm high with a 5 mm stroke, (i) upon release, the locking device must be reset manually by the actuation of the switch referred to in Clause (d), (j) the operation of any by-pass switch, where provided for testing of the fire alarm system, causes an audible signal and a visual signal to be indicated at the fire alarm annunciator panel and at the monitoring station of Clauses 3.2.4.7.(4)(a), (b) or (c), and (k) emergency lighting is provided at the doors. (5) Except as permitted in Sentences (6) and (6.1), electromagnetic locks are not permitted to be installed on exit doors (a) described in Clauses 3.4.6.15.(2)(a), (b) or (c), (b) serving an elementary or secondary school, or (c) leading directly from a high hazard industrial occupancy. (6) Electromagnetic locks are permitted to be installed on an exterior door leading from an exit stairway in a building serving only a Group B, Division 2 major occupancy or a Group B, Division 3 major occupancy. (6.1) Electromagnetic locks are permitted to be installed on an exit door that serves only a gaming premise if (a) the gaming premise is located within a sprinklered floor area, (b) smoke detectors are installed in each room and each corridor accessible to the public, (c) a force of not more than 90 N applied to the door opening hardware initiates an irreversible process that will release the locking device within 15 s and not relock until the door has been opened, and (d) a legible sign conforming with Clause (4) (h) is permanently mounted on the exit door to indicate that the locking device will release within 15 s of applying pressure to the door release hardware. (7) Door hardware for the operation of the doors referred to in this Section shall be installed at a height not more than 1 200 mm above the finished floor.