50109-D-01 Phase Rotation Sequence Indicator
The Model 50109-D-01 Phase Rotation Sequence Indicator is a compact, lightweight instrument designed to save time and energy and eliminate mistakes when connecting loads to polyphase circuits. 
Simplicity, ease of operation and ruggedness are the outstanding features of this indicator.
The instrument may be suspended by its numbered test clips and the correct phase sequence of the supply determined by pressing the switch on the side of the case.

Information as to the rotation or 
sequence of the different phases 
must be known when paralleling generators, 
connecting induction motors, replacing 
transformers, changing lines and services 
supplying any polyphase load. 

This instrument may be used interchangeably
on 110, 220, 440, 550 volt circuits of either
25 or 60 cycles.

Meets specifications of Spec. MIL-1-16103
Weight: 1 1/4 pounds
Size: 1 1/2" thick x 3 1/2" diameter
Case: Molded bakelite with unbreakable crystal
Voltage: 3 Phase, 110/220/440/550 volts, 25/60 cycles.
Specials: 400 or 1,000 cycle and switchboard mounting units are available.