Name: Weidmuller WTR 4 Test-Disconnect Terminal Block - INOSAKI
SKU: Weidmuller-7910180000
Price: 1.56 USD
Availability: InStock

Technical Overview

The Weidmüller WTR 4 (Part No. 7910180000) is a modular test-disconnect terminal block designed for reliable circuit isolation and testing in industrial environments. Featuring a robust pivoting disconnect lever, it allows for safe voltage-free measurement and troubleshooting without removing conductors. The unit is built with a screw connection system supporting a rated cross-section of 4 mm² and is housed in dark beige Wemid thermoplastic with a UL 94 V-0 flammability rating. Rated for 500 V and 32 A (IEC), it also carries ATEX and IECEx certifications (Ex ec II C Gc) for use in hazardous areas (Zone 2).

Key Features

Modular test-disconnect design with pivoting lever
Screw connection technology for secure vibration-resistant termination
Rated for 500 V / 32 A (IEC) and 300 V / 10 A (UL)
ATEX and IECEx certified for explosive atmospheres (Ex ec II C Gc)
Compact 6.1 mm width compatible with TS 35 DIN rail
Robust Wemid construction with operating temperature up to 120 °C
Accommodates conductors up to 4 mm² (AWG 10)
Integrated test sockets for standard 2.3 mm test plugs

Technical Specification Matrix

Technical Parameter	Specification
Product Type	Test-disconnect terminal
Connection Method	Screw connection
Number of Levels	1
Number of Connections	2
Rated Cross-Section	4 mm²
Color	Dark beige
Insulating Material	Wemid
Flammability Rating	UL 94 V-0
Depth including DIN rail	49 mm
Rated Voltage (IEC)	500 V
Rated Current (IEC)	32 A
Current at Max. Conductor	32 A
Volume Resistance	1 mΩ
Power Loss	1.02 W
Rated Impulse Withstand Voltage	6 kV
Pollution Severity	3
Surge Voltage Category	III
Tightening Torque	0.5 - 0.6 Nm
Stripping Length	13 mm
Clamping Screw	M 2.5
Continuous Operating Temp., Min.	-50 °C
Continuous Operating Temp., Max.	120 °C
Storage Temperature	-25 °C...55 °C
ATEX Certificate No.	DEMKO14ATEX1389U
IECEx Certificate No.	IECEXUL14.0097U
Max. Voltage (ATEX/IECEx)	400 V
Current (ATEX/IECEx)	25 A
Max. Cross-Section (ATEX/IECEx)	4 mm²
Marking EN 60079-7	Ex ec II C Gc
Marking Ex 2014/34/EU	II 3 G D
Mounting Rail	TS 35
Clamping Range, Rated Connection, Min.	0.05 mm²
Clamping Range, Rated Connection, Max.	6 mm²
Conductor Connection Cross-Section, Solid, Min.	0.5 mm²
Conductor Connection Cross-Section, Solid, Max.	6 mm²
Conductor Connection Cross-Section, Stranded, Min.	1.5 mm²
Conductor Connection Cross-Section, Stranded, Max.	6 mm²
Conductor Connection Cross-Section, Finely Stranded, Min.	0.5 mm²
Conductor Connection Cross-Section, Finely Stranded, Max.	4 mm²
Conductor Connection Cross-Section, Finely Stranded with Wire-End Ferrules, Min.	0.5 mm²
Conductor Connection Cross-Section, Finely Stranded with Wire-End Ferrules, Max.	4 mm²
Width	6.1 mm
Height	60 mm
Depth	48 mm
Blade Size	0.6 x 3.5 mm
Conductor Size (UL) Min.	22 AWG
Conductor Size (UL) Max.	10 AWG
Voltage Size C (UL)	300 V
Current Size C (UL)	20 A
Conductor Size (CSA) Min.	22 AWG
Conductor Size (CSA) Max.	10 AWG
Voltage Size C (CSA)	300 V
Current Size C (CSA)	10 A
Net Weight	11.554 g

Industrial Applications

1. Signal Loop Isolation in Process Control

Utilized in DCS and PLC marshalling cabinets to manage 4-20mA analog signal loops. The terminal block allows technicians to disconnect specific sensors or actuators for calibration and testing via the integrated test sockets without physically disconnecting wires.

Problem Solved

Eliminates the risk of loose connections or short circuits during routine maintenance of sensitive analog signal paths, reducing downtime and wiring errors.

Galvanic isolationSignal marshalling4-20mA loopsTest sockets

2. Secondary Circuit Protection in Substations

Deployed in voltage transformer (VT) secondary circuits within power distribution panels. The disconnect facility provides a safe point to isolate metering and protection relays for injection testing.

Problem Solved

Ensures operator safety and prevents short circuits in VT loops during commissioning or maintenance by providing a clear, visible break point.

VT circuitsInjection testingProtection relaysSecondary injection

3. Hazardous Area Instrumentation Maintenance

Installed in Ex e / Ex ec certified junction boxes located in Zone 2 hazardous areas. The terminal facilitates the safe disconnection of field instruments for replacement or verification while maintaining compliance with explosion protection standards.

Problem Solved

Provides a certified, spark-safe disconnect method in explosive atmospheres, facilitating instrument checks without violating Zone 2 compliance.

ATEX Zone 2Ex ec II C GcExplosion protectionInstrument isolation