A long conductor voltage drop problem exists with a load that varies with demand. Can a Buck Boost Transformer be used in this application?

Issue:
Can Buck Boost Transformers be used for long wire runs for variable loads?

Product Line:
LV Transformers

Environment:
Buck Boost Transformers

Cause:
Resistance of wires in long wire runs causes a voltage drop that increases with the length of wire.

Resolution:

Since the load is not constant, the buck boost transformer is not a viable option. The voltage drop through the feeder conductors varies with the amount of current flowing through them. A buck boost is field connected to give a fixed percentage of voltage change. With a varying load, the customer could end up with too little voltage a the maximum load and too much voltage at the minimum load, either of which could be detrimental to the load(s).

The viable solution is to step up the voltage using either an isolation transformer or an autotransformer to transmit the electrical energy at as high a voltage possible to minimize the current, and hence minimize the voltage drop. Then use a second isolation transformer to step down the voltage at the point of use. Often, the second transformer may have primary taps which can allow for additional voltage correction at the load to maximize the performance of the overall system, while not presenting too high a voltage to the load equipment at the minimum loading. Contact Product Marketing/Support via the Field Office for support with issues of this nature.

Determining what is considered a short run and a long run is based on the wire size used, the FLA, the voltage, and the environment. This is determined by the installer or an electrical engineer.

Released for:Schneider Electric USA