benderWR70x175S(P)…WR200x500S(P) Measuring current transformers

Product description

The highly sensitive WR…S series measuring current transformers of rectangular type 

convert AC currents into evaluable measurement signals, in combination with RCM and 

RCMS series residual current monitors and evaluators. 

In addition, the measuring current transformers can be used in combination with insulation 

fault location systems (EDS) for IT systems. They are designed to measure the locating 

current generated by a PGH locating current injector or an ISOMETER® IRDH. In combination 

with EDS series insulation fault locators the test current is converted into evaluable signals.

The WR…SP series measuring current transformers feature an integrated screening. 

This screening is intended to avoid false tripping of connected RCM… or EDS… devices, 

when high load currents or inrush currents occur in the system being monitored. 

WR…SP series measuring current transformers are particularly suitable for use in busbar 

systems and are designed for load currents ≥ 500 A.

Connection to the respective device is via a two-wire cable.

Device features

• For RCMS460/490 residual current monitoring systems

• For RCM420 residual current monitors

• For EDS470, EDS460/490 and EDS440 insulation fault locators in AC and DC systems

• The WR…SP measuring current transformers are particularly suitable for use in busbar 

systems. This series is to be used for load currents ≥ 500 A.

Standards and approvals

WR70x175S(P)…WR200x500S(P) measuring 

current transformers comply with the device 

standards: 

• DIN EN 60044-1

• IEC 61869

Dimensions (mm) and weights (g)

Type WR70x175S(P)…WR150x350S(P)

Technical data

Insulation coordination acc. to IEC 61869-2

Highest system voltage for electrical equipment Um AC 720 V

Rated impulse withstand voltage Uisol 3 kV

Measuring circuit

Rated transformation ratio 600/1

Rated burden 180 Ω

Rated primary current ≤ 10 A (100 A)

Rated primary current ≥ 10 mA

Nominal power 50 mVA

Rated frequency 50…400 Hz

Internal resistance 5…8 Ω

Secondary overvoltage protection suppressor diode P6KE6V8CP

Accuracy class 5

Rated continuous thermal current 100 A

Rated short-time thermal current 14 kA/1 s

Rated dynamic current 35 kA/30 ms

Environment

Shock resistance IEC 60068-2-27 (device in operation) 15 g/11 ms

Bumping IEC 60068-2-29 (transport) 40 g/6 s

Vibration resistance IEC 60068-2-6 (device in operation) 1 g/10…150 Hz

Vibration resistance IEC 60068-2-6 (transport) 2 g/10…150 Hz

Ambient temperature (during operation) -10…+50 °C

Ambient temperature (during storage) -40…+70 °C

Climatic class acc. to DIN IEC 60721-3-3 3K22

Connection

Connection screw-type terminals

Connection 

rigid/flexible 0.2…4/0.2…2.5 mm²

flexible with ferrules with/without plastic sleeve 0.25…2.5 mm²

Conductor sizes (AWG) 24…12

Connection to the evaluator

single wire ≥ 0.75 mm² 0…1 m

single wire, twisted ≥ 0.75 mm² 0…10 m

shielded cable ≥ 0.6 mm² 0…40 m

Shielded cable (shield on one side connected to PE) recommended: J-Y(St)Y min. 2 x 0.6

Other

Operating mode continuous operation

Mounting any position

Degree of protection, internal components (DIN EN 60529) IP40

Degree of protection, terminals (DIN EN 60529) IP20

Screw mounting M5

Flammability class UL94 V-0

Documentation number D00144

Installation instructions

• Do not pass shielded cables through the measuring current 

transformer.

• As a general principle, the PE conductor and low-resistance 

conductor loops must not be passed through the measuring 

current transformer!