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140U-LTD3-D40

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The Allen-Bradley/Rockwell Automation 140U-LTD3-D40 trip unit is a Bulletin 140U series trip unit. It can be installed in an Allen-Bradley Bulletin 140U series Size L breaker frame to create a Size L circuit breaker with a molded case. The 140U-LTD3-D40 trip unit supports thermal and magnetic tripping and it has 3 poles. The thermal trip rating is fixed, but the magnetic trip rating can be adjusted by the users. The 140U-LTD3-D40 trip unit should not be used at ambient temperatures above 40 degrees Celsius or 104 degrees Fahrenheit.

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Technical specifications for 140U-LTD3-D40

Brand	Allen-Bradley / Rockwell Automation
Series	140U MCB
Part Number	140U-LTD3-D40
Product Description	Trip Unit
Frame	L
No. of Poles	3
Protection Type	Thermal/Magnetic
Rated Current	400 Amps
Adjustment Range (Thermal Trip)	400 Amps
Adjustment Range (Magnetic Trip)	2000-4000 Amps
Compatibility	600 Amps, L Frame, MCCB

Rockwell Disclaimer: The product is used surplus. DO Supply is not an authorized surplus dealer or affiliate for the Manufacturer of this product. The product may have older date codes or be an older series than that available direct from the factory or authorized dealers. Because DO Supply is not an authorized distributor of this product, the Original Manufacturer's warranty does not apply. While many Allen-Bradley PLC products will have firmware already installed, DO Supply makes no representation as to whether a PLC product will or will not have firmware and, if it does have firmware, whether the firmware is the revision level that you need for your application. DO Supply also makes no representations as to your ability or right to download or otherwise obtain firmware for the product from Rockwell, its distributors, or any other source. DO Supply also makes no representations as to your right to install any such firmware on the product. DO Supply will not obtain or supply firmware on your behalf. It is your obligation to comply with the terms of any End-User License Agreement or similar document related to obtaining or installing firmware.

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The Allen-Bradley 140U-LTD3-D40 Trip Unit comes with the thermal/magnetic protection type and 400 Amps of rated current. It is compatible with 600 Amps rated Frame L 3-pole molded case circuit breakers (MCCBs). The adjustable current range of the magnetic trip is 2000 to 4000 Amps. This trip unit can be used to provide short circuit protection, ground fault protection, and thermal overload protection. This is an electromagnetic switch that has current and thermal sensitivity. This trip unit is designed to sense the high current that is caused by a short circuit so it can stop it to protect the equipment in large electrical circuits. The 140U-LTD3-D40 Trip Unit also has a manual trip button that can trip the breaker manually.

The 140U-LTD3-D40 Trip Unit is the part of the MCCB which determines when to open the contacts. To activate the trip mechanism, the bimetallic strip bends to a predetermined distance and it makes a contact with the trip bar. The actions of the magnetic field that is generated inside the trip unit force the contacts apart in a faulty current. It also has adjustable magnetic elements to provide short circuit protection. The thermal-magnetic trip provides protection against long term current overloads that last longer than 10 seconds. It can be used to provide protection to networks through line distribution and protection for long cables. In normal conditions, the bimetallic contact allows the electrical current to flow through the MCCB. The 140U-LTD3-D40 Trip Unit is temperature-sensitive. After the installation, with the circuit breaker in the tripped position, make sure that the stationary interface barriers are properly installed in the base.