Low-Voltage Phase Testers

A low-voltage phase tester shows whether the conductors at two separate points of a three-phase system belong to the same phase. Carried out before a bypass cable, a back-up supply or a new panel is connected, this check prevents phase-to-phase short circuits and equipment damage. Meter teams of distribution network operators, site electricians, panel builders and maintenance contractors are the main users.

The most typical scenario is meter replacement without interrupting the supply. Before the meter is removed, a temporary bypass cable is connected between the supply and load sides; it must be verified before this connection that both ends of the cable are on the same phase.

Which model?

Model	Operating voltage	Typical use
HPL-200W	AC 70 V – 1 kV (three-phase)	Phase coincidence before meter replacement, bypass and panel connections

The HPL-200W has R, S and T clips; during the test, two of them are attached to the points to be compared. The result is read from an LED: if the two points are on the same phase the LED flashes, if they are on different phases it stays lit. A decision can therefore be made on site without an additional measuring instrument.

Points to note in use

• The HPL-200W is a phase comparison device; a low-voltage detector must be used to verify that a line is dead.
• Wear insulating gloves and eye protection when attaching the clips to live conductors; do not connect the bypass cable until the clips are secured.
• This device is not used on systems above 1 kV; for medium voltage see medium / high-voltage phase testers.
• Do not test with a device whose clips or leads show cracks or insulation damage.

All models, including medium-voltage options, are listed on the phase testers page. The test steps are described in our article What Is a Phase Tester and How Is It Used?.

Frequently Asked Questions

Does the HPL-200W also show phase sequence?

The defined function of the HPL-200W is the same phase / different phase check; phase sequence detection is not included in its technical data. If you also need a phase sequence check, tell us about your application and we will assess a suitable solution with you.

Can it be used on single-phase supplies?

The device is specified for three-phase systems. Please consult us about use on single-phase connections.