Description
Bender WR150X350S | Ground Fault & Residual Current CT Specs
Dynamic Product Introduction
Operating high-capacity busbar trunking systems or heavy industrial power distribution networks without reliable ground fault sensing creates severe arc flash and unplanned shutdown risks. The Bender WR150X350S (Art. No: B98080614) is a specialized rectangular measuring current transformer designed for residual current monitoring (RCM) and insulation fault location systems (EDS). Featuring a large 150 mm x 350 mm rectangular inner window, it easily encloses massive copper busbars or multi-conductor cable groups, detecting minute vector imbalance currents down to the milliamp range without core saturation.
When an operational current transformer suffers insulation breakdown, terminal block physical damage, or core signal distortion from mechanical impact, sourcing an exact-fit Bender WR150X350S replacement restores electrical safety monitoring instantly. Installing a fully bench-tested replacement transformer allows maintenance personnel to mount the sensor around existing busbar runs without re-engineering mounting brackets or recalibrating evaluation relay response curves. Swapping out a compromised sensor restores continuous ground fault surveillance, precise trip threshold tracking, and total plant safety compliance.
WR150X350S
Key Technical Specifications
- Model Designation: WR150X350S
- Article Number: B98080614
- Manufacturer: Bender GmbH & Co. KG
- System Compatibility: Bender RCM Series, RCMS Series, and EDS Series Fault Monitors
- Inner Window Dimensions: 150 mm x 350 mm (5.91 in x 13.78 in)
- Transformer Ratio / Response: High-precision transformation ratio tailored for ultra-sensitive residual current evaluation
- Insulation Rating: Rated insulation voltage 1000 V AC / DC
- Frequency Range: 42 Hz to 2 kHz
- Secondary Connection: Screw-type or spring-cage terminal blocks with terminal shield covers
- Operating Temperature Range: -10°C to +50°C (14°F to 122°F)
- Storage Temperature Range: -25°C to +70°C (-13°F to 158°F)
Global Sourcing & Live-Test SOP (Transparency Core)
Procuring secondary-market electrical safety components like the Bender WR150X350S demands rigorous testing to confirm core magnetic permeability, winding ratio accuracy, and signal output linearity. Every incoming measuring current transformer passes through an intensive five-stage quality assurance protocol:
- Inbound Verification: Part numbers (WR150X350S / B98080614), manufacturer nameplates, and housing structural integrity are verified against Bender factory specifications. Technicians inspect the inner window surface, terminal contacts, and mounting feet for cracks or thermal degradation.
- Live Simulation: The WR150X350S is placed on a high-current test bench equipped with primary current injection sets and linked to a calibrated Bender RCMS monitoring relay.
- Diagnostics: Technicians pass precision multi-turn primary conductor loops through the 150 x 350 mm window, injecting simulated differential fault currents from 10 mA up to 10 A. The sensor’s secondary output signal linearity, phase displacement, and frequency response are measured to ensure zero drift. The unit then undergoes a 24-hour thermal soak under ambient power conditions to verify coil resistance stability.
- Final Prep: Terminal contacts are cleaned and treated with non-conductive protectant, protective terminal covers are verified, and the transformer is packaged in static-shielding ESD material prior to dispatch.
The Field Engineer’s Pitfall Guide
- ❗ Failing to Enclose All Phase and Neutral Conductors: —though you might expect standard CT installation rules, passing phase conductors through the window while routing the neutral conductor outside (or omitting PE shield grounds) will cause false vector imbalance readings and immediate nuisance trips.
- ❗ Routing Protective Earth (PE) Grounding Straps Through the CT Window: Passing a metallic enclosure ground strap back through the inner window cancels out the fault current magnetic flux, rendering the Bender monitoring relay completely blind to real downstream ground faults.
- ❗ Over-Torquing Terminal Screw Contacts: Excessive torque applied to the secondary signal output terminals can crack internal PCB connection pads, creating intermittent open-circuit faults on the signal line.
Intent-Driven FAQ
What is the primary function of the Bender WR150X350S measuring current transformer?
The WR150X350S detects vector sum residual (ground fault) currents across phase and neutral conductors in large power distribution networks, transferring proportional micro-current signals to Bender RCM or EDS evaluation relays.
Can the WR150X350S be used for direct over-current measuring or metering?
No. The WR150X350S is a specialized residual current transformer designed specifically for fault current detection and insulation monitoring. It is not rated or calibrated for standard line-current metering or energy monitoring instrumentation.
What causes a “CT Wire Break” warning on the connected Bender evaluation relay?
A “CT Wire Break” alarm indicates an open circuit or high resistance along the secondary connection cable between the WR150X350S terminals and the evaluation relay input ports.
Does the WR150X350S require an external auxiliary power supply?
No. The measuring transformer operates passively, converting magnetic flux imbalances into secondary output signals driven directly by the monitored primary fault currents. The evaluation relay itself provides all required monitoring power.
What warranty coverage comes with pre-inspected replacement current transformers?
All verified Bender WR150X350S measuring transformers come backed by a comprehensive 1-year replacement warranty. If the unit experiences core saturation drift, winding open circuits, or output signal loss under standard operating conditions within 12 months, it is swapped directly from available warehouse inventory stock.
