OVERVIEW

Official designation: Allen-Bradley 140U-MTD3-D60 (Bulletin 140U, Thermal-Magnetic Trip Unit)

This product is a 3-pole thermal-magnetic trip unit designed for M-frame Molded Case Circuit Breakers to provide fixed long-time (overload) and adjustable instantaneous (short-circuit) protection in industrial applications.

KEY SPECS SUMMARY

Power: 600V maximum rated voltage

Interfaces / Ports: Three pole current sensing elements

Indicators: Refer to the latest manufacturer manual.

Operating Temp: Minus 8.9 to 60 degrees C ambient

Platform / Compatibility: Bulletin 140U M-frame MCCBs

Limit: Magnetic trip adjustable 3000 to 6000 Amps

Lifecycle: Discontinued, replacement recommended.

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What is the continuous ampere rating and the fixed thermal trip setting of this unit?

A: The continuous rating is 600 Amps, and the thermal trip setting is also fixed at 600 Amps.

Wiring & Installation:

Q: What frame size circuit breaker is the 140U-MTD3-D60 trip unit designed for?

A: This trip unit is specifically designed for use with the 800A M-frame molded case circuit breakers.

Troubleshooting & Compatibility:

Q: How is the instantaneous magnetic trip setting adjusted on this thermal-magnetic unit?

A: The magnetic trip setting is adjustable using a screwdriver on the adjustment buttons on the front face of the trip unit.

Replacement & Upgrades:

Q: Is this 140U-MTD3-D60 trip unit still actively manufactured or is a replacement recommended?

A: This specific trip unit is listed as discontinued by the manufacturer, and an electronic LSI unit may be a suitable replacement.