Polyphaser Applications Guide

Product Applications

ac power Protectors: Use at ac mains, subpanels and extension outlets throughout the building. The PSP model can be mounted inside the device to be protected.

dc Power Protectors: Use in solar power systems and other dc current systems. The open circuit voltage of the battery must be less than the turn-on voltage value of the protector.

Grounding Solutions: Everything for grounding applications except the ground rods. PEPs, PEEPs and PBs come with everything necessary for a complete installation: boots, copper straps, hardware, etc. Use PEPs and PEEPs for "thinwall" buildings and PBs for "thickwall" (cinderblock and concrete) structures.

Test Equipment: Use of a Lightning Strike Counter will record the number of strikes and how many times your PolyPhasers have protected your equipment.

Twisted Pair/Cable Protectors: Available for twisted pair telephone wiring carrying data nd voice for both discrete and punchdown block configurations; alarm circuits (current loop); and rotor control lines.

RF Coupled Shield/dc Blocked:Provides the ultimate in protection. Both the center conductor and the shield are dc blocked. Especially useful when the capability of the ground system to handle the surge is either inadequate or questionable. Also prevents ground loops and achieves the proper single point ground.

dc Blocked Filter: Use with passive (no pre-amp) antennas. These will NOT pass the dc (or 60Hz ac) voltage(s) duplexed onto the center conductor. They provide maintenance-free service and the industry's lowest throughput energy.

dc Blocked/Gas Tube: Use with passive (no pre-amp) antennas. These will NOT pass the dc (or 60Hz ac) voltage(s) duplexed onto the center conductor for feeding pre-amps, relays or sequencers. Use in single transmitter situations only. If combiners are used, a combiner protector should be specified.

dc Injector/dc Path: Protects active antennas, pre-amps or other situations requiring a dc (or ac) voltage on the center conductor. The dc and RF paths (RF is dc-blocked) are separated, individually protected, and recombined. Also bias-T models for injecting the dc onto the center conductor or picking off the dc to feed the powered device. The bias-T models are receive only.

Combiner Protectors: For multi-channel or multi-transmitter applications. Refer to formula in APPENDIX 'B' to ensure that the total voltage does not exceed the "Vt" rating of the protector, or call for technical assistance.

dc Type & Isolated Shield: For coax-based baseband LANs (e.g. 10 BASE T), closed circuit television (CCTV) security monitors, and HF Receive only. To prevent hum bars due to ground loops, use the IGA-90V to isolate the shield of the camera-mounted protector from each ground.

Grounding Components:

Rack Isolation Kit: Isolates the rack from conductive floors (concrete). Eliminates a current path through sensitive equipment.


Bulkhead to Flange Adapter: Adapts most PolyPhaser bulKhead-mounted protectors to mount on a single point grounding panel or similar flat surface. The connector on the antenna (surge) side must be female; i.e. will not work with the -MA versions.


Low Inductance Copper Grounding Strap: To achieve a low inductance ground system. Copper strap has a larger surface area and lower inductance per foot than equivalent cross section circular wire.


Copper Strap Bonding Clamps: To bond copper strap without building up the joint for an exothermic weld. Use for connecting the copper strap radial to the ground rod; to transition from copper strap to wire [sizes #6AWG to #4/0AWG], and bonding different widths of copper strap to each other.



Copper to Tower Leg Corrosion Free Grounding Clamps: Use for attaching copper strap to a galvanized tower leg. Maximizes the contact surface area and prevents corrosion due to dissimilar metals. Eliminates the need for exothermic welding to the tower.


Wire/Copper Rod Transition
Bonds the copper strap radial to the (copper-plated) ground rod without building up the joint for an exothermic weld.


Copper Cleaning Kit and Copper Primer Kit: For best results, the copper should be brought down to "white metal" before bonding and weather sealing. To paint the copper straps and entrance panels use our copper primer kit.


Weather Proofing Kit: When a PolyPhaser model designed for inside use must be mounted outdoors and unprotected, use the weather proofing kit to prevent moisture ingress. The kit can easily handle extreme temperatures, and is unaffected by the sun's ultra-violet (UV) rays.

Tower Accessory Protectors: Often forgotten and therefore a "sneak path" for the lightning surge energy, the wiring associated with the tower lights or obstruction strobe lamps should be protected.

Coax Protection

To determine the Proper protector application, the following should be considered:

IMPEDANCE: 50 and 75 ohm protectors are standard. Other impedance available as custom product.

SPEED: Primarily for lightning protect or for defined lightning and Nuclear Electro Magnetic Pulse ( NEMP) threats. Most of the protectors do well for both, but for some military applications high speed protection may be necessary.

FREQUENCY RANGE There are broad coverage and single band gas tube or filter models. Most of lightning's energy is in the lower frequency range of ac to 1.0MHz. The further away from this range, the less the amount of energy that will get through to the equipment (throughput energy). Always choose the lowest through put energy for the desired frequency range.

TRANSMIT (XMIT), TRANSCEIVE (XCV) OR RECEIVE ONLY (RO) If multip[e transmitters are combined, the number of XMIT signals is important. Gas tube protectors are voltage sensitive and multi-XMIT signals are voltage additive. Two 100 watt XMIT signals combined equal 200 watts of heating power but the additive voltages have peaks of 200V, which equate to a single 400 watt signal. Therefore, multi-channel simultaneous XMIT systems must have a higher turn-on voltage and be designed to handle higher peak instantaneous RF currents. This peak turn-on voltage calculation is not required for filter type protectors (no gas tube). (See "COMBINER PROTECTORS" section.)

TRANSMIT POWER (CONTINUOUS AND/OR PEAK) As the frequency is increased in a gas tube type protector, the power handling is reduced. This is done to be sure the protector will turn off after a lightning strike or EMP firing and not be "kept alive" in a glow mode by the presence of the RF transmit energy. The turn-on voltage is determined by the protector power rating. Since most PolyPhaser units do not have dc continuity, little protection is lost by going to a higher turn-on voltage unit especially if XMIT combining is planned in the future. This is not a concern with filter type units (no gas tube).

PRESENCE OF AC OR DC POWER WITH THE RF SIGNALS Usually for receive only situations such as tower top preamps and down converters. However, there are units available for cellular and PC.S. ranges to accommodate the higher current requirements of tower top transmit amplifiers. Units are listed for dc injector pickoff and for protecting already injected coax lines (pickor model).

MOUNTING Bulkhead panels are recommended. (Bulkhead panel) systems are listed as grounding components.) Flange style may be mounted on a bus bar or a single point ground panel. A ground strap larger than the total sum of all the circumferences of the coax shields should be used to connect to a low inductance ground system. For more on grounding, see our listed book The "Grounds" for Lightning & EMP Protection.

CONNECTOR TYPE AND SEX Type N connectors are standard. DIN, TNC, BNC, SMA, F, LC, and EIA male and female are stocked connectors. These and others are available for some models at an additional cost. The connector sex can be chosen for male and/or female combinations except for some microwave models). The male is always the one with the outside moveable shell and solid center pin (See diagram in APPENDIX C for connector pictorials.)


Data/Phone Line Protection

Telephone central offices and computer rooms have many things in common. Both have computers connected to data or phone lines, local area networks LAN), and phone channel banks (T-carrier). All are interconnected to the "outside world" with twisted pair coaxial cable or fibre optic interfaces.

Telephone line protectors supplied by the phone company are a first line of defense, but are not always connected to a high current capacity, fast transient response ground system. PolyPhaser offers a series of data and telco protectors when a higher level of protection is required.

LAN and T-carriers require protectors that have wide bandwidths for high frequency data with tightly controlled surge energy specifications. If our catalog products do not match your requirement, we can supply a custom designed product for your application.

Other special protectors are available for telco span line and repeater current loop lines. Please contact us at 1-800-543-8790.


Power Line Protection

For lightning and EMP, shunt type protectors will limit the voltages to a safe level for most non-electronic equipment. In-line type protectors are preferred for electronic equipment survival. In-line units should be mounted/grounded close to the protected equipment. For mainframe computers and broadcast equipment, in-line power mains protectors are listed which provide single or polyphase protection with EMI/RFI filtering.

For power line protector selection, the voltages, number of phases, configuration. current usage (in-line only), will pinpoint the model. Voltages to 480Vac are listed for single to three phase applications. All models (except IS-PSP-120 and IS-PSP-240) have built in end-of-life protection. Replacement modules and breakers are sold separately for most models. The 100/200A in-line, 120/208 240 shunt, and both PSP models are NRTL or CSA listed



Grounding is so important that we wrote a book about it (The 'Grounds' for Lightning & EMP Protection). Proper grounding is necessary to disperse lightning energy into the earth, away from electronic equipment as quickly as possible.

The ground system needs to be integrated with proper lightning protectors for your application. Comm-Omni provides the products, knowledge, and consulting services to help design and maintain your lightning protection system.

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The Need for Coax Protection

Skin effect is a physical phenomenon that relates to the limited penetration into a conductor of an RF signal according to its frequency. Coax uses this effect to keep the RF signal inside its shield and any external coupling interference on its outside surface. This effect begins to degrade as the frequency is lowered (transfer impedance). The RF penetration, which is a gradient, begins to mix the shield's outside interference energy with the desired inside energy. A ground loop, which imparts 60hz onto a desired signal is due to dissimilar grounds causing ac current flow between points via the coax shield, coupling unwanted energy to the center conductor.

With lightning the main frequency range is dc to 1 MHz. This is in the range that affects the coax transfer impedance. The thicker the coax shield material, the less the effect of these low frequency currents.

A simulated lightning test was performed on 51 feet of 1/2" hard line. The center conductor was connected to the shield on one end simulating a shunt-fed antenna. For the test, 1050 amperes of current was pulsed to individual 0.01 ohm resistors at the far end. The voltage drop across the current viewing resistors went to separate channels on a digital storage scope. Due to a lower inductance, the shield pulse arrived first. The center conductor had more inductance so the pulse was spread out in time. The energy (area under the curves) was exactly the same for both the shield and the center conductor.

Since the pulses arrive at different times, a differential voltage occurs that must be equalized and pre- vented from reaching the equipment input. This is precisely what the patented PolyPhaser products do to provide the ultimate protection.


PolyPhaser's Coaxial Impulse Suppressors


For Frequency/Product Chart, go here

PolyPhaser Corporation's coaxial impulse suppressors are a unique line of patented products. Hermetically sealed voltage sensitive gas tubes are used on most models with additional components to assure that surge voltages and currents formed differently on the coax are not conducted to the equipment input. There is no dc continuity from center pin to center pin on our dc blocked protectors.

Other gas tube protectors have ac continuity through their center pins and share the energy with the equipment before the gas tube turns on. If the equipment has an inductor to ground as the first component, the differential voltage must first propagate through the coax jumper to the equipment, then create enough inductive voltage drop across the combined inductances (coax cable jumper and input inductor) to turn on the gas tube.

Since the gas tube turn on voltage must be rated above transmitter power (Ep=1.414/PZ), a considerable inductive voltage drop (E-L di/dt) must occur for the gas tube to fire. The voltage required to fire the gas tube is directly related ot pulse rise time and current flow through the combined inductances to ground. Typically, 10,000 amps (peak) through the equipment input circuitry to ground is required to develop the L di/dt voltage needed to fire the gas tube in a dc continuity coax protector. The equipment is subject to a 10,000 amp pulse before the protector can turn on!

Quarter wave stub protectors are also dc coupled devices. There is dc continuity between center pins. However, instead of a broad band voltage sensitive device (gas tube), quarter wave stub protectors are a tuned band pass filter. A grounded quarter wave matching section in the device presents a high impedance to the center conductor at the designed operating band and a low impedance to ground for all other frequencies. Since most of lightning's energy is at dc or frequencies up to 1MHz, these type of protectors would appear to be ideal.

Antennas are a tuned circuit and will ring at their operating frequency when hit with a fast rise time voltage pulse (lightning). This on frequency ringing voltage will propagate

down the coax with other lower lightning frequencies. The quarter wave stub will, at best, divide the lower frequency energies, sending most to ground. Some of the other frequency energy and all of the on frequency energy will go to the equipment input. A gas tube protector is voltage sensitive, regardless of frequency, and will conduct the ringing voltage to ground.

A PolyPhaser dc blocked protector only lets through our rated specification (low milli-, or microjoules). Peak voltage let-through is also significantly less than dc continuity protectors. PolyPhaser's measured let-through energy and voltage are the industry's lowest.

PolyPhaser's new dc blocked, non gas tube, weather resistant impulse suppressors continue our tradition of superior RF and surge performance. These new "Microwave Filter" devices with band passes from 800MHz up, represent the best protection available for CELLULAR through PCS. (and above) equipment. Unlike quarter wave stubs, our filter protectors exhibit a wide flat band pass with very low VSWR and insertion loss. With average power level capabilities up to 750 watts, they are the best choice for critical high power applications.

Since PolyPhaser's Microwave Filters are dc blocked (quarter wave stub filters are not), the PolyPhaser filter does not "share" lightning energy with the equipment input. Detailed let-through voltage and energy specifications are published in this catalog.

Peak current ratings on coaxial protectors vary with different manufacturers. A higher peak current rating does not always mean a better protector. For example, consider a self supporting tower with 9 antennas and one microwave down link for a total of 10 coaxial cables. An average strike would be 20kA However, let's calculate a 100kA strike (less than 1 percent of all strikes). The tower would conduct 70kA to ground. The remaining 30kA is divided between 10 coax cables, or 3kA on each cable. Since most of the peak current is on the shield, about 1 kA would be on the center conductor. When applying the above current division principle to a tower system, it is easy to see why PolyPhaser's 20kA rating is more than adequate.

ac Power Protectors


There are several ways in which your equipment can be damaged via the power line. One is a strike elsewhere on the power line inducing a surge that travels to your equipment. However, a strike to your tower or a coupled surge to the phone lines can also damage equipment since the power line can provide an alternate path to ground. To ensure survival, all inputs and outputs (I/Os) must not only be protected but must be bonded in common via a common low inductance conductor to an earth ground. All grounds should be bonded in the earth to form a single earth ground.

Power mains protectors are to be placed at the entrance panels, transfer switches or distribution panels. They should have a low inductance path to the earth system and be installed with the minimal lead inductance (short with gradual bends). For best protection, have an additional in-line power protector at or very near the sensitive equipment. This should not be a protector that uses only the wall outlet safety ground. It should be a protector that can be mounted/grounded (like the IS-PLDO or IS-MSRP) to your main earth system.

TYPES OF POWER MAINS CONFIGURATIONS Power mains come in several different configurations. The three basic ones are single, bi-phase and three-phase. Three-phase is sometimes called polyphase and has further divisional classes using the letters "Y" (written "Wye", and a triangle denoting the Greek letter Delta).

SINGLE PHASE This is the simplest. It has a live or hot fee, a return called a neutral and a safety ground. This is commonly used for secondary wiring for a normal outlet. It may be any worldwide standard voltage. For the U.S.A., it is 120Vac (see drawing).

BI-PHASE This is a common feed configuration. It may be obtained by either a single transformer, center tapped or by grounding one phase of a three phase delta. The former is often called single phase in the U.S.A. since it often uses a single, center tapped transformer feed from one of three high line phases. These phases are 180 degrees from each other so 120Vac is available as well as 240Vac. This is typical for most houses in the U.S.A. (see drawing).

POLYPHASE OR THREE PHASE This is the feed for large facilities. The phases are 120 degrees apart. The Wye configuration normally always has a neutral return which is grounded. The true delta (called a closed delta) normally does not have a ground. There is an open delta where a high leg (red lead) has a higher voltage to ground than the rest and there is a ground lead. A grounded delta has one leg grounded (see drawings).

VOLTAGES AVAILABLE AND WHERE USED Voltages to 480Vac are used for normal feeds. The voltages will depend on the type of feed and your country. Measure the phase to phase voltages and the phase to ground voltages to determine the type of service, then check the current rating on the (largest) cut-off breaker.

CONNECTIONS FOR PROTECTORS The connections for the protectors are given for each model and service type. Only the voltages change. The wires are properly color-coded for identification.

SHUNT OR IN-LINE AND WHERE TO USE EACH In-line protectors are load bearing; shunt types are not. In-lines are presently available up to 200A. These have redundancy, better surge limiting an provide filtering. Shunt types have no real load current limit, however, the larger the load, the larger the wires, and the more the surge energy will follow the conductors with the largest surface area. This means that more than one protector should be used. Two shunt protectors separated by twenty feet of wiring in steel conduit almost equal a single in-line protector. Both types have alarm contacts and field replaceable surge components.

NRTL UL 1449 APPROVAL PolyPhaser employs the services of CSA and MET Laboratories, Inc. to test and certify its products. These Nationally Recognized Testing Laboratories (NRTL) are approved by OSHA in the U.S.A. CSA is also approved by Federal, State, City and Municipal jurisdictions throughout the U.S.A. Both agencies test to all applicable standards including UL, ANSI, IEEE, NFPA, etc. Both agencies are approved by the National Institute of Standards and Technology (NIST) through the National Voluntary Laboratory Accreditation Program (NVAP) and are a National Certified Body in the IECEE Scheme. CSA and MET labels are accepted throughout the U.S.A. and in most countries.