Simply connect the lead wire clips to a main circuit so that the phase sequences and open phases can be easily checked.

Since the connections between the lead wires and main unit are safely constructed so that the live side is a plug-socket type, live parts are not exposed even if the socket is disconnected by chance.

Lamp indication of measurement results allows reliable judgment.

The maul unit requiring no batteries for measurement and indication. is economical. At check time, however, circuit voltage needs to be applied.