Kidde KI-HFD Intelligent Fixed Temperature Heat Detector

Key Features:

  • Next generation heat sensing technology
  • 135 °F (57 °C) fixed temperature alarm point
  • Uses existing wiring
  • Automatic device mapping
  • Sensor Markings provide easy testing identification
  • Up to 250 total devices per loop
  • Non-volatile memory
  • Electronic addressing
  • Bicolor (green/red) status LED
  • Has cover marking for easy identification during testing
  • Standard, relay, fault isolator, and audible mounting bases
  • 50 foot (15.2 meter) spacing

Note: Some features described here may not be supported by all control systems. Check your control panel’s Installation and Operation Guide for details.

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The KI-HFD is an intelligent fixed-temperature heat detector that contains a fixed-temperature heat sensor rated at 135 °F (57.2 °C). It does not have a rate-of-rise function. The heat sensor monitors the temperature of the air in its surroundings and the detector analyzes the data to determine when the air temperature near the detector exceeds the device’s alarm point.

The KI-HFD fixed temperature detector provides a 135°F (57°C) fixed temperature sensor for slow building-fires.

KI Series detector bases mount to North American 1-gang boxes, 3-1/2 inch or 4-inch octagon boxes, and to 4-inch square electrical boxes 1-1/2 inches (38 mm) deep. They mount to European BESA and 1-gang boxes with 60.3 mm fixing centers. See mounting base installation and wiring for more information.


Sensing and Reporting Technology
The microprocessor in each detector provides additional benefits – Self-diagnostics and History Log, Automatic Device Mapping, and Fast, Stable Communication.

Self-diagnostics and History Log – Each KI Series detector constantly runs self-checks to provide important maintenance information. The results of the self-check are automatically updated and permanently stored in the detector’s non-volatile memory.

Automatic Device Mapping – The loop controller learns where each device’s serial number address is installed relative to other devices on the circuit. The mapping feature provides supervision of each device’s installed location to prevent a detector from being reinstalled (after cleaning etc.) in a different location from where it was originally.

Fast Stable Communication – On-board intelligence means less information needs to be sent between the detector and the loop controller. Other than regular supervisory polling response, the detector only needs to communicate with the loop controller when it has something new to report.


Detector mounting bases have wiring terminals that are accessible from the “room-side” after mounting the base to the electrical box. The bases mount to North American 1-gang boxes and to 3½ inch or 4-inch octagon boxes, 1½ inches (38 mm) deep. They also mount to European BESA and 1-gang boxes with 60.3 mm fixing centers. The KI-SB4, KI-RB4, and KI-IB4 mount to North American 4-inch sq. electrical boxes in addition to the above boxes. They include the GSA-TS4 Trim Skirt, which is used to cover the “mounting ears” on the base. The KI-ABST mounts to a 4-inch square box only.

Remote LED GSA-LED – The remote LED connects to the KI-SB or KI-SB4 Standard Base only. It features a North American size 1-gang plastic faceplate with a white finish and red alarm LED.

GSA-TS4 Trim Skirt – Supplied with 4-inch bases, it can also be ordered separately to use with the other bases to help hide surface imperfections not covered by the smaller bases.

Sounder Bases – KI Series sounder bases are designed for use where localized or group alarm signaling is required.

  • KI-ABST bases provide sounder capability to KI Series to heat and smoke detectors. They are not intended for use with combination carbon monoxide detectors in Fire-plus-CO mode.
  • KI-ABDT bases provide sounder capability to KI Series smoke and heat detectors, as well as carbon monoxide detectors when used with a GSA-T3T4 Temporal Pattern Generator.
  • KI-ABLT bases provide 520 Hz low frequency sounder capability to KI Series smoke and heat detectors, as well as carbon monoxide detectors when used with a GSA-T3T4 Temporal Pattern Generator. The KI-ABLT is suitable for applications requiring low frequency audible tones.


Warnings & Cautions

  • This detector does not operate without electrical power. As fires frequently cause power interruption, discuss further safeguards with the local fire protection specialist.
  • This detector does not sense fires in areas where heat cannot reach the detector. Heat from fires in walls, roofs, or on the opposite side of closed doors may not reach the detector.
  • This heat detector by itself does not provide life safety protection. Use this detector with ionization and/or photoelectric smoke detectors.
  • This detector does not detect oxygen levels, smoke, toxic gases, or flames. Use this device as part of a broad-based life safety program which includes a variety of information sources pertaining to heat and smoke levels, extinguishment systems, visual and audible devices, and other safety measures.
  • Independent studies indicate that heat detectors should only be used when property protection alone is involved. Never rely on heat detectors as the sole means of fire protection.


Typical Wiring
The detector mounting bases accept #18 AWG (0.75mm2), #16 (1.0mm2), #14 AWG (1.5mm2), and #12 AWG (2.5mm²) wire sizes. Sizes #16 AWG (1.0mm2) and #18 AWG (0.75mm2 ) are preferred for ease of installation.

Standard Detector Base, KI-SB, KI-SB4
This is the basic mounting base for Kidde KI Series detectors. The GSA-LED Remote LED is supported by this base.

Isolator Detector Base, KI-IB, KI-IB4
This base includes a built-in line fault isolator for use on Class A circuits. A detector must be installed for it to operate. The isolator base does not support the GSA-LED Remote LED.

The isolator operates as follows:

  • a short on the line causes all isolators to open within 23 msec
  • at 10 msec intervals, beginning on one side of the Class A circuit nearest the loop controller, the isolators close to provide the next isolator down the line with power
  • when the isolator next to the short closes, it reopens within 10 msec.

The process repeats beginning on the other side of the loop controller.

Relay Detector Base, KI-RB, KI-RB4
This base includes a relay. Normally Open or Normally Closed operation is selected during installation. The dry contact is rated for 1 amp (pilot duty) @ 30 Vdc. The relay’s position is supervised to avoid accidentally jarring it out of position. The KI-RB can be operated as a control relay if programmed to do so at the control panel. The relay base does not support the GSA-LED Remote LED.

Audible Sounder Bases, Fire Mode
ABDT, ABST, ABLT sounder bases

Technical Specifications

Operating voltage 15.20 to 19.95 VDC
Normal operating current 51 µA
Alarm current 68 µA
Vibration level 10 to 35 Hz, with an amplitude of 0.01 in.
Rate-of-rise rating NA
Fixed temperature rating 135°F (57.2°C). Actual alarm point 129 to 141°F (53.9 to 60.6°C).
Maximum spacing 50 ft. (15.2 m) centers
Compatible detector testers Testifire 2000
Operating environment 32 to 100°F (0 to 38°C), 0 to 93% RH, noncondensing
Construction High Impact Engineering Polymer, White
Storage temperature -4 to 140°F (-20 to 60°C)
Agency Listings CAN/ULC-S530-M91, UL 521
Weight .4 lbs
Construction Polymer
Programming Electronic
Material Qualities High Impact Resistance
Series KI Series
Thermal Rating 135°F
Condition New
Detection Method Fixed Temperature