Phase Rotation Sequence Indicator.
Used to determine proper sequence on all polyphase circuits prior to connecting phase sensitive loads such as pumps or motors, paralleling generating sources or replacing transformers. 
Series 560 Phase Rotation Sequence Indicators will indicate presence of all phases as well as phase sequencing. 
Both phase sequence indicators display clockwise and counterclockwise rotation on two jumbo LED’s. 
It includes a battery test switch with high reliability circuitry and construction

The Model 50109-G-01 Phase Sequence Indicator 
offers a frequency range from 25 to 1000 Hertz 
with voltage range from 60 to 600 volts for 
determining sequence in polyphase circuits.

The Model 50109-G-02 Phase Rotation Sequence Indicator operates on a frequency range of 60 Hertz
with a voltage range intended for 4160 volts to
determine sequence in polyphase circuits.

The 50109-G-01 and the 50109-G-02 Phase Rotation Sequence Indicators are both housed in a high impact plastic case and have permanently attached leads with fully insulated color coded spring clips for easy identification and fast hookup. The battery test switch is conveniently located on the front of the unit and positioned to avoid inadvertent activation during storage. Slide open battery compartment facilitates easy 9-volt battery replacement