ABB A3N 400 TMF 400-4000 3-Pole MCCB (50°C Rated)
The ABB A3N 400 TMF 400-4000 is a fixed three-pole moulded case circuit breaker from the ABB Formula series, rated at 400A with a thermomagnetic (TMF) release and certified for continuous operation at 50°C ambient temperature. This higher ambient rating makes it particularly well suited to UAE plant rooms, rooftop switchrooms, and outdoor enclosures where sustained heat and dust are common operating conditions.
Key Features
- 3-pole 400A moulded case circuit breaker with fixed thermomagnetic (TMF) release for dependable overload and short-circuit protection.
- Rated for continuous operation at 50°C ambient, suited to high-temperature UAE plant rooms and unconditioned switchrooms.
- 36kA ultimate breaking capacity (Icu) and 18kA service breaking capacity (Ics) at 415V AC for demanding fault-level applications.
- N short-circuit performance level suited to main incomer and heavy industrial duty.
- Front terminal connection for straightforward installation and wiring access in panel builds.
Technical Specifications
| Specification |
Details |
| Brand |
ABB |
| Model |
A3N 400 TMF 400-4000 3p F F 50°C |
| Product Series |
SACE Formula |
| Poles |
3 |
| Rated Current (In) |
400A |
| Rated Uninterrupted Current (Iu) |
400A |
| Ambient Temperature Rating |
50°C |
| Release Type |
TMF (Thermomagnetic, Fixed) |
| Short-Circuit Performance Level |
N |
| Rated Operational Voltage |
550V AC / 250V DC |
| Rated Insulation Voltage (Ui) |
690V |
| Rated Impulse Withstand Voltage (Uimp) |
6kV |
| Breaking Capacity Icu (415V AC) |
36kA |
| Breaking Capacity Ics (415V AC) |
18kA |
| Terminal Connection |
Front |
| Mounting |
Fixed |
| Mechanical Durability |
5,000 cycles |
| Electrical Durability |
2,000 cycles |
| Dimensions (W x H x D) |
139.5 x 205 x 103.5mm |
| Weight |
4.75kg |
Applications
- Main incomer protection in UAE plant rooms and rooftop switchrooms exposed to high ambient heat
- Large feeder and transformer secondary protection in commercial and industrial buildings
- Generator and motor control centre protection in unconditioned or semi-outdoor enclosures
- Distribution board upgrades and MCCB replacements where sustained high-temperature operation is a factor
FAQ
-
What's the difference between an MCB and an MCCB?
An MCB (miniature circuit breaker) is typically rated up to 100A with a fixed, non-adjustable trip and lower breaking capacity, used for final circuits. An MCCB (moulded case circuit breaker) is built for higher currents and fault levels, and is used for main incomers, sub-mains, and feeder protection where an MCB's rating or breaking capacity would be insufficient.
-
When do I need an MCCB instead of an MCB?
Use an MCCB where the prospective fault current or load current exceeds what an MCB is rated to handle safely — typically at the main incomer or major sub-main level of a commercial or industrial distribution board.
-
Does this MCCB have an adjustable trip setting?
Check the specific trip unit type in the Technical Specifications table above — thermal-magnetic MCCBs may have a fixed or adjustable trip range depending on the model; an electronic trip unit typically offers configurable protection curves.
-
Can I install this myself?
No. MCCBs are installed in distribution boards and panels by a licensed electrician, in line with UAE wiring regulations.
