Impulse Phaser
Cable Identification System
Cable Phasing System
Cat. No. 541001-10; -20; -30

  • Easy to understand and use
  • Increased safety for operating personnel
  • Accurately identifies cables in trenches, vaults, conduits and enclosures.
  • Identifies jacketed, shielded cables, even in pipe
  • Accurately identifies phases in multiconductor cable
General: The IMPULSE PHASER was originally developed in early 1950 to increase personnel safety when working on paper insulated, lead covered cables. Since its introduction, the IMPULSE PHASER has been used safely and reliably by electric utilities throughout the U.S.

With the introduction of direct buried, solid dielectric primary voltage cables, the IMPULSE PHASER has come into greater prominence for safely and accurately identifying buried primary cables, including jacketed neutral designs. The IMPULSE PHASER has been accurately used on paper insulated, lead covered feeders in excess of 20 miles and even on submarine cable 300 feet underwater.

Increased safety and reliability: Because safety is of paramount importance, the IMPULSE PHASER is designed to operate only if the cable circuit to which it is connected has been shorted and grounded. Also, the transmitted signal cannot be imposed on any other cable in the circuit. Either at the point of the connection or the point of identification, the IMPULSE PHASER promotes safe, positive identification of cables.

Most instruments available today are adversely affected when:

  • the cable surface is dirty
  • the test probe is accidentally shorted to ground
  • the cable has a jacket over the shield
The IMPULSE PHASER is not adversely affected by any of the noted potential problems. In fact, you can identify shielded cables within metallic conduits!

Simple operating procedure: The first step in identifying a feeder circuit with the IMPULSE PHASER is to de-energize and ground the circuit. The IMPULSE PHASER transmitter is attached at one end of the feeder, the transmitter grounds are removed and the transmitter is turned on. Once the IMPULSE PHASER transmitter is connected and indicates it is operating properly, there is no need to remain with it. At the location where the cable is to be identified, the clamp-on is attached to the detector and the cable or phase is then identified using the color coded detector meter- it's as easy as that.

Identification of direct buried primary cable is just as easy. De-energize and ground the cable between the two pad mounted transformers. In one of the transformers, on the cable to be identified, ground the conductor to all of the neutral conductors in the transformer. At the other end, connect the IMPULSE PHASER transmitter red "A" phase lead to the conductor to be identified. Connect the yellow "B" phase lead to all of the commonly connected neutrals and turn the IMPULSE PHASER on. At the open trench, use the clamp-on around each cable to obtain a meter deflection. One of the cables will give a red "A" phase meter deflection - that's the cable to be worked on.

Versatile power supply: The IMPULSE PHASER employs a dual AC-DC power supply circuit. When used in an area where no AC power is available, the system functions using a sealed rechargeable battery. The transmitter battery has approximately 18 hours of impulsing time before recharging is necessary. The transmitter unit has a built-in charging system that will recharge the battery if necessary whenever the transmitter is connected to an A.C. source. During operation using 120 volts AC, should anyone accidentally disconnect the electrical plug, the IMPULSE PHASER automatically switches over to the battery power. The detector uses a standard 9v battery.

Accommodating larger cable diameters: Because the electric power industry is using larger jacketed buried cables, it became necessary to introduce clamp-ons that could be clamped over the larger cables. TIMCO INSTRUMENTS can provide clamp-ons with openings of 1 1/4", 2 1/8", and 5". Any size can be specified when ordering an instrument.

Fast, economical service: The IMPULSE PHASER is a ruggedly constructed instrument which should need little or no attention. However, from time to time, some factory maintenance may be required. With our electric utility background, we know the importance of repairing and returning the instrument quickly. During any repair, the system is automatically upgraded to conform to the latest design specifications to insure increased reliability and service for life.

Physical size: The IMPULSE PHASER is compactly housed in a rugged, steel carrying case for portability. The carrying case tray holds all of the standard accessories including the clamp-on.

If you need to unequivocally identify a cable or establish phases, you need the...

Technical Description:

The IMPULSE PHASER transmitter discharges a directional current pulse into a shorted loop of cable. This current pulse is detected by using a clamp-on type current transducer as the input to the detector unit. The detector unit interprets the polarity of the input signal, thereby making the clamp-on orientation sensitive. A label on the clamp-on indicates the proper orientation of the clamp-on to assure accurate deflections of the meter. In the case of phasing cables, the current pulse travels down the cable connected to the red output lead and returns on the cable connected to the yellow lead. The signal will not be present on any other cables. Since the connected cable lengths form a series circuit, the meter deflections will be the same magnitude along the entire length of both cables in the loop. This permits the phasing of the cables along the entire run, for example, in several manholes.

When using the IMPULSE PHASER to identify a single phase, normally all of the neutrals and the earth are used as the signal return. In this case, the current pulse travels down the phase to be identified, then returns via multiple paths to the yellow output lead. If sufficient return paths are used, the meter sensitivity can be adjusted to give a normal half scale deflection on the red phase, and the yellow return paths will cause a weak opposite deflection or no response.

The transmitter will not pulse and a red indicator will light to indicate that the transmitter is connected to an open or high resistance circuit or to an ungrounded circuit. The yellow indicator flashes when the transmitter is discharging the current pulses.

The detector unit is activated by a momentary contact push-button switch to extend battery life. Meter zero position and sensitivity can be controlled by the operator. A four pin connector attaches the clamp-on to the detector unit.

Impulse Phaser Specifications Page

Impulse Phaser Application Notes Page

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