Frequently Asked Questions
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Protectowire PLR models are manufactured with special low resistance tri-metallic inner conductors that enable the use of longer detector zone lengths on most types of fire alarm panels including addressable.
The maximum length of Protectowire Digital Linear Heat Detector that will be compatible with a manufacturers fire alarm control panel is determined by the initiating device circuits maximum loop resistance and the per unit length resistance of the linear heat detector. Lower per foot resistance allows for longer detector lengths on the same circuit.
Protectowire’s PHSC digital linear heat detectors have an approximate resistance of 0.185 Ohms per foot (0.607 Ohm per Meter).
Protectowire’s PLR digital linear heat detectors have an approximate resistance of 0.058 Ohms per foot (0.191 Ohm per Meter).
PLR models will allow for installed detector lengths approximatly 3x longer on the same initiating device circuit.
Yes, the electrical characteristics of the Protectowire Linear Heat Detector are compatible with most manufacturers control panels. The system designer should confirm Protectowire Linear Heat Detector compatibility with the panel manufacturer. Limitations in the length of Protectowire per zone must be determined due to the resistance of the conductors. Protectowire Control Panels are specifically designed and approved for use with Protectowire Linear Heat Detectors and are recommended to insure compatibility and provide sole source system responsibility.
The listed spacing shall be used as a guide or starting point in detector installation layout. Reduced spacing is required based upon factors such as ceiling height and construction, physical obstructions, air movement, or the Authority Having Jurisdiction (AHJ).
The maximum listed spacing for each type of Protectowire Linear Heat Detector is as follows:
Factory Mutual Listed Spacing for 155°F and 190°F rated Types EPC, EPR, XCR, and XLT – 30 feet (9.14m) on center, Type TRI – 15 feet (4.6 meters) on center. Protectowire 220°F and 280°F Types EPC and XCR – 25 feet (7.6m) on center. Protectowire 356°F Types EPC and XCR rated for proximity detection only and do not have a rated spacing.
Underwriters Laboratories Listed Spacing, for all models (except Type TRI) – 50 feet (15.24 meters) on center. Type TRI is FM approved only and not UL Listed.
Zone length is dependent upon the Protectowire FireSystem Control Panel model series being used. Maximum lengths for current production models are as follows:
– FireSystem 2000 Series Control Panels – 5,000 Feet (1,524m) maximum per zone.
– FireSystem 2600HD Series Control Panels – 5,000 Feet (1,524m) maximum per zone.
– SRP-4×4 Control Panels – 10,000 Feet (3,048m) maximum per zone.
The beginning of the Fiber Optic Linear Heat Detection Cable is fusion spliced to an E2000 pigtail for connection within the controller enclosure. For single ended configurations (Similar to Class B) the end of the Fiber Optic Linear Heat Detector is terminated with a 65 Foot (20M) service loop and then capped. For double ended configuration (Similar to Class A) the end of the Fiber Optic Linear Heat Detector is fusion spliced to a second E2000 pigtail for connection within the controller.
No. Digital linear heat detectors require interposing copper cable to traverse non-protected areas. For Fiber Optic Linear Heat Detectors this is not the case. The same Fiber Optic Linear Heat Detection Cable is run from the controller, through non-protected areas into the protected area. In programming the Fiber Optic Linear Heat Detection Cable in the non-protected area can be configured as a non-detecting section of the overall loop.
The Underwriters Laboratories (UL) listed spacing for the Fiber Optic Linear Heat Detector is 50 Feet on center.
No. The FiberSystem 8000 controller is a detector only. It can be part of a releasing system when monitored as a detector by a fire alarm control panel with releasing capability.
Yes. Splicing of the Fiber Optic Linear Heat Detector requires fiber optic fusion splicing equipment and persons performing splices must be trained in their use.
The same hardware used for digital PHSC type Protectowire Linear Heat detectors is used for installation of the PFS series Fiber Optic Linear Heat Detector.
Provided the detector is not exposed to temperatures exceeding 302 degrees F (150 Degrees C) for a period of over 60 minutes, the detector does not require replacement. Should the maximum exposure temperature be exceeded or is unknown, then replacement of the exposed section is recommended. The replacement fiber optic detector must be fusion spliced to the unaffected existing fiber optic detector.
Commissioning requires programing of the FiberSystem 8000 controller using the specific configuration software. Installers need to attend a custom two day factory training program prior to shipment of the purchased controller. Installers work with the actual unit to be field commissioned.
Unlike standard Protectowire Linear Heat Detectors which operate on a fixed temperature alarm principle, the PFS Series Fiber Optic Detectors are user programmable by zone to operate on any one of the following alarm criteria:
- Maximum temperature per zone.
- Temperature difference between a measurement location and the zone average (zone differential).
- Temperature development per zone in terms of time (time differential / rate-of-rise).
In a conventional fire alarm system, a zone is usually defined as an area which is served by a single initiating device circuit that typically contains multiple detectors. In a fiber-optic based system such as the FiberSystem 8000, a single length of sensor can be partitioned into different segments or “zones” as desired based upon the specific hazard. Zones are defined in system software making it easy to customize zone specific outputs and even overlap them thereby increasing system control capabilities.
Yes, Protectowire Linear Heat Detectors (Excluding Tri-Wire) have the same internal construction and can be spliced directly together on the same initiating device circuit. This allows a single Protectowire Linear Heat Detector zone to protect multiple areas with different ambient temperatures.
All Protectowire FireSystem Control Panels can be provided with our unique Alarm Point Location Meter. This feature allows the control panels to digitally display the linear distance (feet / meters) to the point of overheat.
All Protectowire FireSystem Control Panels can be provided with our unique Alarm Point Location Meter. This feature allows the control panels to digitally display the linear distance in feet or meters to the point of the overheat.
Fire alarm cable variation in gauge size and resistance will affect the allowable run length from the panel to the start point of the zone. Protectowire panels are designed to accommodate up to 100 ohms of feed or interposing cable. The allowable length = 100 ohms divided by the number of ohms per unit length (feet or meters) of feed cable. The maximum allowable feed cable length is typically reduced to 18 ohms when the Alarm Point Location Meter is utilized in the control panel.
The functional operation of Protectowire Linear Heat Detectors is not affected by EMI/RFI. However, initiating device field wiring can act as a pathway for the transmission of EMI/RFI to associated control equipment. Protectowire FireSystem Control Panels have been designed to tolerate most occurrences of EMI/RFI. Installation environments subject to lightning strikes or extreme sources of EMI/RFI should be protected similar to computers and other electronic systems with supplemental commercially available (e.g. Ditek) surge and filter protection.
Yes, the SRP-4×4 can be configured or “programed” into any one of sixteen standard operating programs. The programs are field selectable by utilizing a set of simple to operate dip switches. These preconfigured operating programs will accommodate most, but not all commonly used system operating requirements. Customers with unique or complex releasing requirements should consult the Factory or review the standard program descriptions outlined in the SRP-4×4 Operating Manual available in the Product Section of this website.
The optical detector is an electronic detector containing electro-optical sensors that are sensitive to electromagnetic radiation in the Ultraviolet (UV), Visible (VIS), Infrared (IR) spectral light bands. The optical detector “sees” the fire by detecting the electromagnetic radiation emitted by the combustion products.
Every combustion process emits three types of energy:
- Heat energy – detected by heat detectors
- Radiation energy – detected by optical detectors
- Product energy – contained in unburned products and unstable products of combustion.
The fastest detection method is the Optical analysis of the radiation emitted from a combustion process.
Optical detectors can “see” a fire from a long distance without the need for smoke or heat to get to the detector. Light travels extremely fast so the detector “sees” (reacts) extremely fast to flaming fires that can be up to 215 ft. (65m) away and only 1 ft.2 (0.3m2) in size. This feature makes optical flame detectors very effective in large open or critical areas where other fire detection methods would not work.
All flame detectors have between 90° and up to 120° cone of vision. One can assume that the wider the cone of vision, the more area the detector can cover. However, this is both misleading and in many cases totally incorrect.
In the case of the IR3 detector which has a 100° cone of vision, but can see a 1 ft.2 (0.3m2) fire at a distance of 215 feet (65m), the area the detector can cover is far greater (four times) than that of a detector with a 120° cone of vision which can only see the same size fire at 50 ft. (15m).
Most flame detectors are placed in the corner of a structure so as to get maximum coverage along both walls and into the area. In this scenario the additional 30 degrees is meaningless as it is outside the walls of the building.
When deciding installation locations, The Protectowire Company offers a Laser Detection Area Coverage Pointer that can assist by defining the 90° cone of vision on site.
Since both sensitivity and range are related to fire size, if the detector is placed further away from the fire source, the detectable fire size will vary according to the Inverse Square Law. Therefore, doubling the detection distance results in only 25% of the radiant energy reaching the detector. As a result, in order to retain the same response time, the surface area of the fire then needs to be four times larger.
For example, if a standard UV/IR detector, capable of detecting a 1 ft.2 (0.3m2) fire at 50 ft. (15m), is located at 100 ft. (30m) detection distance, the minimum size fire then needs to be 4 ft. 2 (1.2m2).
The main benefit of CTI technology is short circuit discrimination or the ability to distinguish between thermal activation of the detector and a mechanical short caused by physical damage. This feature greatly reduces the potential for false alarms. Along with this unique feature our CTI linear heat detectors also afford all the benefits of our standard Digital Linear Heat Detectors such as…
Line coverage provides superior sensitivity.
- Compatible with virtually any fire alarm control panel.
- Alarm Point Location.
Suitable for installation in severe environmental conditions.
Easy to install, test, and splice.
CTI technology is an enhancement to standard digital linear heat detection operation. Where traditional digital linear heat detectors have a single mode of detection, CTI digital linear heat detectors add a second mode of detection. This second mode of detection utilizes the thermo-electric effect to measure the temperature at the short circuited point of the detector to confirm a true alarm condition exists.
CTI digital linear heat detectors are constructed of a twisted pair of dissimilar metal spring conductors coated with a thermoplastic coating designed to soften at a specific temperature. An initiating device circuit monitors a length of this detector installed in the area to be protected.
When a short occurs at a point along the detectors length the initiating device circuit of the CTM-530 Interface Module detects the short and then automatically switches to a thermocouple measurement mode. The shorted portion of the detector forms a thermocouple junction and it’s temperature can be measured. The thermocouple measurement represents the current temperature of the shorted portion of detector. If the short is below the pre-set alarm threshold for the installed detector, a short fault is reported instead of an alarm condition. If the short is above the pre-set alarm threshold for the installed detector an alarm condition is reported immediately.
Currently the CTI product line carries Factory Mutual Approval, Underwriters Laboratories Listing & California State Fire Marshal (CSFM) Approval.
Yes. CTI linear heat detectors are constructed using “T” type thermocouple conductors which require all terminations be made via “T” type thermocouple terminals. This is to ensure the temperature measurements made by the CTM-530 which provide short circuit discrimination are as accurate as possible. The Protectowire Company provides a full line of splice terminals and junction boxes specifically designed for compatibility with our CTI linear heat detectors.
Yes. All Protectowire CTI linear heat detectors are compatible with the same mounting hardware and fixings used for our standard digital linear heat detectors. The only exception is that all terminations must be made using “T” type thermocouple terminal blocks. The Protectowire Company provides a full line of splicing terminals and junction boxes specifically designed to be compatible with our CTI linear heat detectors.
Yes. Typically the CTI Linear Heat Detector will connect directly to the CTM-530 Interface Module, when this is not possible, “T” type extension cable can be used to connect the CTI Linear Heat Detector to the CTM-530 Interface Module. For all CTI type detectors, twisted “T” type extension grade thermocouple wire is required for use as interconnecting wire on the detection circuit. Minimum conductor size is 20AWG (0.812mm), or as required by local code.
Explanation: CTI linear heat detectors are constructed using “T” type thermocouple conductors which require all wiring between the CTM-530 Interface Module and the CTI Linear Heat Detector be made with compatible “T” type extension grade thermocouple wire. This is required to ensure the temperature measurements made by the CTM-530 which provide short circuit discrimination are as accurate as possible. Please read the CTM-530 Installation & Operation manual for more information.
No. Unlike our standard Digital Linear Heat Detector which is compatible with any normally open switch type initiating devices, CTI Linear Heat Detectors are not. Only CTI Linear Heat Detectors can be monitored by the CTM-530 Interface Module.