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BCH-2

BCH-2 Cable Identifier

INTRODUCTION
Before repair work can commence on an underground cable, the cable must be positively identified. Many manholes and vaults contain numerous runs of cable and it is imperative that the repair crew does not cut into an energized cable instead of the damaged de-energized cable. This requirement serves as justification for the existence of a cable identifier.

The BCH-2 has the following qualities, which make it an ideal cable-Identifying instrument:

It is able to positively identify a de-energized cable that had been cleared at both ends and the risers removed according to Safety Practice Regulations and Local Operating Orders.
It is compact and easily handled on poles and in manholes.
It can be used with all types of sheathing and protective covering.
It can identify cables in the presence of other cables when all the metal sheaths are bonded together.
It can work effectively on cable lengths greater than seven miles long.
It can work on multiple branch systems.
It is battery powered with an eight-hour battery life and is rechargeable overnight.
It has a battery state indicator.
It can register negative and positive pulses on a zero center indicating panel meter.
The transmitter can be shut off by remote control.
It can identify cables without cutting windows. It can identify separate dead cables. It can determine if tagged cables are correctly identified.
It can "phase" in both directions after a cable cut.

TRANSMITTER
The BCH-2 cable Identifier was developed for use on three phase non-ferrous distribution cables such as PILC belted or XPLE concentric neutral.

The battery powered transmitter generates a 300 V DC pulse which is applied to the "B" and "C" phase of the cable under test, the other end of the cable is terminated by a suitable jumper across "B" and "C" phase of the cables.

The polarity of the DC pulse depends on the direction of the current flow; "B" phase will have a DC pulse opposite in polarity to that of "C" phase

REMOTE TURN OFF
The transmitter has an added feature of "Remote Turn Off". "A" phase is used for this purpose and is usually connected at the same time as "B" and "C" phase.

As a cable is being cut, a momentary short between "A" and "B" or "A" and "C" phases automatically stops the transmitter and removes the open circuit DC voltage.

PHASING
The transmitter has provisions for phasing. After a cable has been cut a diode is switched across "B" and "C" phases inside the transmitter enabling phasing in both directions at the work site.

BATTERY CHARGER
The transmitter has a built in battery charger for the two sealed lead acid batteries that are within the instrument case. A charged transmitter battery will give approximately eight hours of operation.

RECEIVER
The cable identifier receiver is a hand held battery operated solid state device and works in conjunction with an external pick-up coil probe that has been shielded to restrict pick-up to the sensing side of the probe only.