ABB XT3N 250 TMD 3-Pole 250A Moulded Case Circuit Breaker
The ABB XT3N 250 TMD is a fixed three-pole moulded case circuit breaker from the SACE Tmax XT series, fitted with front terminals and a thermomagnetic (TMD) release adjustable across 175-250A. Rated for 690V AC operation with a 36kA breaking capacity at 415V, it is well suited for main and distribution protection duties in UAE commercial and industrial low voltage panels.
Key Features
- Adjustable thermomagnetic TMD release with rated current setting range of 175-250A for flexible protection coordination
- Rated ultimate short-circuit breaking capacity (Icu) of 36kA at 415V AC and 50kA at 220-240V AC, suitable for high fault-level UAE installations
- Front terminal bolt connection with fixed mounting, designed for compact panel and switchboard installation
- AC/DC current type rated up to 690V AC or 500V DC, supporting a wide range of distribution and industrial applications
- Genuine ABB quality — manufactured to IEC 60947-2 standard
Technical Specifications
| Specification |
Details |
| Brand |
ABB |
| Model |
XT3N 250 TMD 250-2500 3p F F |
| Poles |
3P |
| Rated Current (In) |
250A |
| Setting Range |
175-250A |
| Release Type |
TMD (Thermomagnetic) |
| Rated Instantaneous Short-Circuit Setting (Ii) |
2500A |
| Breaking Capacity (Icu at 415V AC) |
36kA |
| Breaking Capacity (Icu at 690V AC) |
5kA |
| Rated Operational Voltage |
690V AC / 500V DC |
| Rated Insulation Voltage (Ui) |
800V |
| Rated Impulse Withstand Voltage (Uimp) |
8kV |
| Terminal Connection |
Front, Bolt type |
| Mounting |
Fixed |
| Standard |
IEC 60947-2 |
| Weight |
1.7 kg |
Applications
- Main incomer protection in low voltage distribution boards for commercial buildings
- Feeder and sub-distribution protection in industrial panels and switchboards
- Motor and installation protection in facilities with high fault-current levels
- Panel builder projects requiring adjustable thermomagnetic protection settings
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.
