- AC Drives
- Industrial Communications
- PLC & I/O Cards
- Vibration Monitoring
- Automation Accessories
- Controllers & Data Acquisition
- Safety Switches & Guard Locking
- CCTV & Security
- Encoders
- Industrial Computers
- HMI Displays
- Motor Soft Starters
- Isolator & Barrier
- Pneumatic Cylinders
- Servo Drives
- Automation Software
- Robotics
- Machine Vision
Brand: Allen-Bradley
Allen-Bradley 140M-D8E-C20 20 A Motor Protection Breaker
Description
14.5-20 A Allen-Bradley 140M breaker, D frame
140M-D8E-C20 is a D-frame member of the Allen-Bradley 140M family, a 3-pole motor protection circuit breaker that sets from 14.5 to 20 A. Short-circuit trip is fixed at 260 A. Reading the catalog number: 140M is the motor protection circuit breaker bulletin, D is the frame, 8 the breaking class (high break (8)), E the trip type (adjustable thermal, fixed magnetic at 13 times In) and C20 the current range code.
The table prints 5.5 / 10 / 11 / 17 kW (230 / 400 / 500 / 690V, AC-3) and 5 / 7.5 / 15 / 20 hp for this range.
Technical specifications
| Parameter | Specification |
|---|---|
| Catalog no. | 140M-D8E-C20 |
| Type | Allen-Bradley 140M motor protection circuit breaker, 3 poles |
| Setting range | 14.5 to 20 A |
| Fixed magnetic release | 260 A (13 x In) |
| Power in kW (230 / 400 / 500 / 690V) | 5.5 / 10 / 11 / 17 kW |
| hp rating (columns per datasheet) | 5 / 7.5 / 15 / 20 hp |
| Frame / breaking class | D / high break (8) |
| Icu / Ics (product page) | 100 kA at 400V / 4 kA at 690V |
| Phase-failure protection | Differential release (phase-loss sensitive) |
| Document | 140M-TD002G datasheet |
Protection data and the high-break rating
The 8 in the catalog number marks the high-break version: Icu 100 kA at 400V at 400V on the product page, Ics 4 kA at 690V. The setting range starts at 14.5 A, so a motor of about 5.5 to 10 kW at 400V falls into the upper part of the range. Magnetic trip is 260 A (13 x 20 A, derived).
Rated power at AC-3 on the product page is 5.5 kW at 230V and 10 kW at 400V, and the highest rating is 7.5 hp at 230V three-phase. About 6 W of power loss at rated load is listed, which feeds the heat calculation for the panel.
Selecting and applying a high-break device
The high-break class suits panels close to transformers where the prospective short-circuit current is high. Check the available fault current at the panel against the Icu and Ics figures, and against the combination ratings for use with 100-C contactors printed in the datasheet.
Set the dial to the nameplate current of the motor (14.5 to 20 A) and keep the starting current below 260 A.
Ordering and documents
For quick comparison only (derived): a 14.5 to 20 A range gives a span of 1.38:1, and the magnetic trip of 260 A equals 13.0 times the top setting. The nameplate current of the motor determines the real setting.
Quote 140M-D8E-C20 in full. Rockwell’s datasheet 140M-TD002G (January 2018) is the hosted document; the product-page values quoted above were checked on the Rockwell product page. Contactors, auxiliary contacts, busbars and enclosures are separate catalog numbers.
Seven Star LLC is an independent supplier in Muscat and quotes on request; please confirm every rating against the current Rockwell documents before ordering.
When requesting 140M-D8E-C20, tell us how the motor is started, how many starts per hour you expect, the control voltage and the short-circuit rating needed. With these facts we can compare your design with the datasheet values and mention any open points (140M-D frame motor protection breaker, 14.5 to 20 A, 260 A magnetic trip, high break).
Browse more items in Circuit Breakers on our site, or send us the part number for a quotation.
Datasheets & Documents
- Datasheet Motor Protection Circuit Breaker and Motor Circuit Protector Specifications, Bulletin 140M (140M-TD002G-EN-P, January 2018) Download
Reviews (0)
About brand
Allen-Bradley is the brand of Rockwell Automation for industrial control: ControlLogix and CompactLogix controllers, I/O systems, PanelView operator terminals, PowerFlex drives, motor control and industrial network equipment. The company began in Milwaukee in 1903, when Lynde Bradley and Dr. Stanton Allen formed the Compression Rheostat Company to make the motor speed controller Bradley had invented in 1901. It took the name Allen-Bradley in 1909 and was bought by Rockwell International in 1985. Since 2001 its owner has been Rockwell Automation, which is still headquartered in Milwaukee, Wisconsin.
Allen-Bradley company profile
| Founded | 1903, Milwaukee, Wisconsin, USA, as the Compression Rheostat Company |
|---|---|
| Founders | Lynde Bradley (inventor of the compression rheostat, 1901) and Dr. Stanton Allen (investor); Harry Bradley joined in 1904 |
| Name | Allen-Bradley Company from 1909 |
| Ownership | Acquired by Rockwell International in 1985 for about USD 1.65 billion; a brand of Rockwell Automation (NYSE: ROK) since 2001 |
| Headquarters | Milwaukee, Wisconsin, USA |
| Product families | Logix programmable automation controllers (ControlLogix, CompactLogix), legacy SLC 500 and MicroLogix PLCs, Micro800 controllers, POINT, FLEX and Compact I/O, PanelView HMIs, PowerFlex AC drives, contactors, motor starters and soft starters, safety components, Stratix Ethernet switches |
Milestones
- 1901: Lynde Bradley invents the compression rheostat to control the speed of electric motors.
- 1903: The Compression Rheostat Company is formed in Milwaukee with an initial investment of USD 1,000.
- 1904: Harry Bradley joins; a crane controller is shown at the St. Louis World's Fair.
- 1909: The company is renamed Allen-Bradley.
- 1985: Rockwell International acquires Allen-Bradley.
- 2001: Rockwell Automation becomes the company's name; the Allen-Bradley brand marks 100 years in 2003.
Reading Allen-Bradley catalogue numbers
The first digits of an Allen-Bradley catalogue number identify the platform, which tells you what is compatible with what. 1756 is ControlLogix (chassis-based, used for large process and plant control), 1769 is CompactLogix 5370 with Compact I/O, 5069 is CompactLogix 5380 with Compact 5000 I/O, 1734 is POINT I/O, 1794 and 5094 are FLEX and FLEX 5000 distributed I/O, 1746 and 1747 belong to the older SLC 500 family, 1766 is MicroLogix 1400 and 2080 is Micro800. For drives, 25B is PowerFlex 525 and 22B is PowerFlex 40; in a code such as 25B-D010N114, "D" means 380–480 V, "010" is the output current rating, and N114 instead of N104 means the drive has an integrated EMC filter. Many plants in the region still run SLC 500 and older MicroLogix systems, which Rockwell has discontinued, so exact spares and migration to CompactLogix are both common requests.
Where Allen-Bradley products are used
In Oman and the GCC, Allen-Bradley controllers and drives run on oil and gas facilities, water treatment and pumping stations, cement, food and beverage and packaging plants, and on machines supplied by American OEMs. ControlLogix is often the platform for plant control systems, while PowerFlex drives are used on pumps, fans and conveyors.
Allen-Bradley products we list
| Family | Examples |
|---|---|
| ControlLogix | 1756-L85E, 1756-EN2T, 1756-EN2TR, 1756-IF16, 1756-IB32, 1756-PA75, 1756-A10 |
| CompactLogix and Micro controllers | 5069-L320ER, 5069-L340ERM, 1769-L33ER, 1769-L16ER, MicroLogix 1400, Micro820, SLC 500 (1746) |
| Distributed I/O | 1734-AENTR, 1734-IB8, 1734-IE2C, 1734-IB8S safety, 1794-AENTR, 5094-AENTR, 5069-IF8 |
| Operator terminals | PanelView Plus 7 10-inch, PanelView Plus 7 15-inch, PanelView 800, PanelView 5310 |
| Drives, motor control and networking | PowerFlex 525, PowerFlex 755, PowerFlex 4, 150-A180NBD SMC, Stratix 2000, 1783-NATR |
Ordering Allen-Bradley products: what we need
Send the full catalogue number and the series letter from the label (for example 1756-EN2T Series D), because firmware and compatibility can change between series. For drives, add the motor power, voltage and filter option. For a discontinued SLC 500 or MicroLogix part, tell us whether you need the exact spare or a migration proposal.
Facts checked against Rockwell Automation's published company history, October 2026.
Browse Allen-Bradley products by category: PLC & I/O Cards, AC Drives.
Related products
Frequently Asked Questions
What current range does 140M-D8E-C20 cover?
It is adjustable from 14.5 to 20 A.
What is the magnetic trip of 140M-D8E-C20?
Fixed at 260 A, which is 13 times the maximum setting.
What does the E in 140M-D8E-C20 mean?
Adjustable thermal release with a fixed magnetic release at 13 x In, per the catalog decode in 140M-TD002G.
What motor power does 140M-D8E-C20 protect?
AC-3 power ratings are 5.5 / 10 / 11 / 17 kW at 230 / 400 / 500 / 690V.
Does 140M-D8E-C20 include a contactor?
No. It is a motor protection circuit breaker; a contactor such as a 100-C is ordered separately.
Reviews
There are no reviews yet.