The Raytech three phase voltage system option T-Rex is an optional system accessory for 3-
Phase transformer ratio meter test sets designed by Raytech (i.e. TR-MARK III).
T-Rex was designed to give Engineers and Test Technicians the ability to test the phase
relationships and actual voltage ratios of transformer windings while applying three phase
The system (in connection with a 3 phase Raytech Turns Ratio Meter) precisely measures the ratio and angular relationship of transformer phases
with voltage applied to all three phases simultaneously. This is a “real condition”
measurement, which allows greater understanding of how the transformer will operate
connected to a 3 phase system.
The T-Rex is especially useful for transformers with:
• Phase relationships other than multipels of 30°.
• Zig Zag windings.
• Uncentered neutral points.
• Suspected broken, damaged, or missing core laminations.
The T-Rex is contained within a separate yellow case and comes complete to connect to the
Raytech TR-Spy, TR-MARK II or TR-MARK III three phase transformer ratio meter.