Product Specification Sheet APS278

Rev. 01/2014

SF118/3B Emergency Call Switch

This Specsheet is for a product which is discontinued. Please contact us for alternative products.
Architects' And Engineers' Specifications

The Emergency Call switch shall be Alpha Communications® / TekTone model SF118/3B or approved equal with pull cord operated switch, mounted on a durable ABS plastic faceplate, marked "EMERGENCY". Canceling the call shall be possible only at the point of origin. Unit shall mount on single-gang electric "gem" box or plaster ring. Unit shall feature a mechanical 'call placed' Red indicator, that activates when the cord is pulled, as well as a Red L.E.D. call-placed indicator. 

The Emergency Call switch may be used with the CM800 series annunciator(s), on systems that require the interfacing to form 'C' relays from customer provided smoke detectors.

Contractor shall observe all local and national electrical and building codes.


The Alpha Communications® / TekTone SF118/3B Emergency Switch is designed for emergency-call systems that need to interface to a customer supplied smoke detector (form 'C') relay output, and features a rugged, long-life, positive acting switch mounted on a durable ABS plastic faceplate. Signaling an emergency requires just a short pull on the 6' long nylon cord, in any direction. The signal cannot be canceled except at the point of origin.

The SF118/3B provides the circuits to operate signaling devices, such as a remote annunciator lamp, a corridor dome lamp, floor bell(s), individual apartment electric door openers, and smoke detector relay interfaces, as needed.

A unique feature of the SF118/3B series pull cords is that it has a mechanical indicator window that turns 'Red' when the pull station is activated. This provides a 'call placed' or 'call assurance' capability without the need for any lamp indicators, additional power supplies, or additional wiring.

The SF118/3B features a rugged, long-life, positive-acting switch mounted on a flame retardant type ABS plastic faceplate marked "EMERGENCY" that includes a red call placed LED., with a special diode network to allow for the smoke detector relay interface.


Dimensions: Height: 4.50" (114mm) (less cord)
Width: 2.75" (70mm)
Depth: 1.50" (38mm) (into wall)
Faceplate: White ABS plastic.
Switch: SF118/3B - 4PDT with special diode network for smoke detector interface
Positive screw terminals
Mounting: Standard single-gang electrical box
Marking: "EMERGENCY" in Black Letters 
Indicators: Mechanical 'Red' window AND Red call-placed L.E.D. indicator
Wiring Requirements
Refer to system wiring diagram IL514 for more complete wiring information.
Alpha Communications
42 Central Drive • Farmingdale • NY • 11735-1202 • Phone: (631) 777-5500 • Fax: (631) 777-5599
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Due to continuous product improvement, all colors, sizes, materials, finishes and specifications are subject to change without notice.