Products Details
Precision Electronically Compensated Current Transformer
Common Mode Rejecter for testing meters with interconnected current and voltage circuits

The Common Mode Rejecter (CMR) is an electronically compensated uncoupling unit for elimination of interaction of simultaneously tested electricity meters having interconnected current and voltage circuits (closed I-P links).

The CMR-I 1x30 is universal small-sized electronically controlled precision current transformer unit for galvanically isolating current. The through-hole, single wire unit with possibility of user defined current ratio is dedicated for testing of electricity meters with closed current and potential circuits. Versatility of the unit enables utilization in extensive applications as step-up or step-down precision current transducer with excellent dynamics.

The CMR-I 1x30 is constructed as universally applicable standalone unit with easy implementation to any existing test bench system. The unit has negligible additional power loss therefore no power increase is needed for closed link test capability. The unit enables any user defined current ratio between primary and secondary circuit. The current ratio is defined by primary and secondary coil via number of respective turns. The internal electronics of the device assures exact primary and secondary ampere-turns equality.


• Standalone through-hole universal transformer with single wire capability
• Excellent accuracy and dynamics
• Built-in open circuit and overload protection
• Easy user-friendly mounting, negligible power loss and built-in protection permit simple extension of any existing meter test equipment to closed I-P link testing capability
• No short circuit of unused positions needed (the unit without load is in protection state shorted automatically)
• Unity transfer ratio of the CMR unit enables simple user test of functionality and accuracy
• Up or down current transformation with specified accuracy


CMR-I 1130
CMR-I 1230
CMR-I 1330
Output / Input Ratio
user defined (1:1 for single wire circuit)
Dynamics > 100 000 (120 A : 1 mA for single wire)
Max. Ampere-turns
120 A
2 x 120 A
3 x 120 A
Max. Output Power
36 VA
2 x 36 VA
3 x 36 VA
Max. Output Voltage
0.3 V / turn
Operating Frequency
45 .. 65 Hz
Max. Load Resistance
0.05 ohm / turn²
Current Range
100 000 (1 mA to 120 A for single wire 1:1 ratio)
Max. Amplitude Error
0.05 % (CMR-I 1x30A) , 0.02 % (CMR-I 1x30E)
Max. Phase Error
0.03 ° (CMR-I 1x30A) , 0.01 ° (CMR-I 1x30E)
Overload, Open Circuit
Hole Diameter
26 mm
Size (L x H x D)
160 x 90 x 120 mm
160 x 170 x 120 mm
160 x 250 x 120 mm
approx. 5 kg
approx. 7 kg
approx. 9 kg
Power Supply
PSCI 1220A
-for up to 20 CMR-I 1330
Input Voltage Range : 85 .. 264 VAC / 50 .. 60 Hz
-for up to 30 CMR-I 1230
Size (L x H x D) : 100 x 118 x 220 mm
-for up to 60 CMR-I 1130
Weight : approx. 2 kg

Precision Electronically Compensated Current Transformer
CMR-I 1330
CMR-I Power Supply PSCI 1220A
CMR-I usage
Power supply connections