Frequently Asked Questions

Protectowire PHSC series is manufactured using spring steel conductors, while the PLR series is manufactured with low resistance tri-metallic conductors that are engineered to enable longer detector zone lengths on other manufacturers' control equipment. The amount of Protectowire (PHSC or PLR series) that can be installed on another manufacturers' control equipment is directly determined by the maximum loop resistance of the equipment’s initiating device 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). The PLR series detectors allow for approximately 3x longer lengths on the same initiating device circuit.

Yes. Protectowire linear heat detectors are resistive normally open contact devices that are compatible with most manufacturers’ control panels. The system designer should confirm Protectowire Linear Heat Detector compatibility with the panel manufacturer. Maximum zone lengths are determined by the resistance of the conductors. Protectowire Control Panels and interface modules are specifically designed and approved for use with Protectowire Linear Heat Detectors and are recommended to ensure compatibility and provide sole source system responsibility.    

The listed spacing should be used as a guide or starting point in the 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, XCR, and XLT: 30 feet (9.14m) 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 are rated for proximity detection only and do not have a rated spacing
• Underwriters Laboratories Listed Spacing for All Models: 50 feet (15.24 meters) on center

Zone length is dependent on the Protectowire control equipment being used. Maximum lengths for current production models are as follows:

• PIM-530 Interface Module: 6,500 feet (2,000m) maximum per zone
• 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

Yes. Protectowire offers two series of detectors capable of supporting different activation temperatures on the same series initiating device circuit. This allows a single Protectowire Linear Heat Detector zone to protect multiple areas with different ambient temperatures. The PHSC Series can support 135°F, 155°F, 190°F, 220°F, 280°F and 356°F being spliced into the same initiating device circuit. The PLR Series can support 155°F and 190°F being spliced into the same initiating device circuit.

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 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. Anyone performing splices must be trained in their use.

Provided the detector is not exposed to temperatures exceeding 302° F (150° 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.

Yes. 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 offers two series of detectors capable of supporting different activation temperatures on the same series initiating device circuit. This allows a single Protectowire Linear Heat Detector zone to protect multiple areas with different ambient temperatures. The PHSC Series can support 135°F, 155°F, 190°F, 220°F, 280°F and 356°F being spliced into the same initiating device circuit. The PLR Series can support 155°F and 190°F being spliced into the same initiating device circuit.

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 is 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 or RFI. However, initiating device field wiring can act as a pathway for the transmission of EMI and RFI to associated control equipment. Protectowire FireSystem Control Panels have been designed to tolerate most occurrences of EMI and RFI. Installation environments subject to lightning strikes or extreme sources of EMI or RFI should be protected, similar to computers and other electronic systems with supplemental commercially available surge and filter protection (e.g. Ditek).

Yes. The SRP-4×4 can be configured or programmed 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.

The optical detector is an electronic detector containing electro-optical sensors that are sensitive to electromagnetic radiation in the ultraviolet (UV), visible (VIS) and 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 feet (65m) away and only 1 foot 2 inches (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 foot 2 inch (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 feet (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° is meaningless as it is outside the walls of the building. When deciding installation locations, Protectowire 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, 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 foot 2 inch (0.3m2) fire at 50 feet (15m), is located at 100 feet (30m) detection distance, the minimum size fire then needs to be 4 feet 2 inches (1.2 m2).

The main benefit of CTI technology is short circuit discrimination, also known as 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, including:

• 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 Digital (PHSC) 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 detector's 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 its temperature can be measured. The thermocouple measurement represents the current temperature of the shorted portion of the 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 (FM), Underwriters Laboratories Listing (UL) and 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. Protectowire 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. Protectowire 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.

No. Unlike our Digital (PHSC) 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.

Yes, but only when using the CTM-530E-I interface module and if the installation is in compliance with Protectowire Control Drawing IL-1622. The CTM-530E-I is FM-approved and provides intrinsically safe connections suitable for monitoring CTI Linear Heat Detectors installed in Class I, II or III, Division I, applicable groups A, B C, D, E, F and G classified areas. Protectowire Control Drawing IL-1622 provides instruction on how to properly install both the CTM-530E-I and CTI Linear Heat Detector to comply with the requirements for intrinsically safe circuitry.