Model 936A Reference Current Transformer

The Arbiter Systems®, Inc. Model 936A Reference Current Transformer provides laboratory grade accuracy in a small, portable, ruggedized case, making it ideal for field use. Multiple ratios of 1200:5, 1000:5, 800:5, 600:5 are selectable via a front panel switch. The guaranteed accuracy over the full input range and operating conditions is 0.02 % ratio and 0.01 ° phase (traceable to NIST), ideal for calibrating other current transformers.

The Model 936A uses an active transformer to achieve the high accuracy needed for a primary reference. This design incorporates a dual core toroid with an amplifier aided second stage. The active circuitry reduces the sense transformer core flux to zero and produces an accurate output current independent of burden. The Model 936A was designed primarily for use with the Model 935A Current Source and the Model 931A Power System Analyzer to calibrate current transformers used with the Model 1133A Power Sentinel. The Model 936A’s multiple ratio selections allow other current transformers to be tested and calibrated across their entire operating range.




Input Range 1 Arms to 1200 Arms
Current Ratios 1200:5, 1000:5, 800:5, 600:5


Current 5 Arms maximum
Voltage 8.5 Vrms maximum



Size 205 mm x 305 mm x 225 mm (8 in x 12 in x 8.75 in)
483 mm x 483 mm x 483 mm (16 in x 16 in x 16 in), shipping
Weight 5.8 kg (12.8 lbs) maximum
Current Transformer 55 mm (2.125 in) ID Nominal, 3 m (10 ft) cable length


Temperature Operating: 0 °C to + 40 °C
Nonoperating: – 40 °C to + 85 °C
Humidity Noncondensing

Power Requirements

External Power

Range 85 Vac to 264 Vac, 47 Hz to 440 Hz, 15 VA maximum or 110 Vdc to 250 Vdc, 15 W maximum
Safety Designed to meet UL, CSA, VDE Standard


Inlet IEC-320 with fuse and mating cordset. Specify P01 – P10.