Description
TERASAKI ELECTRIC CO., LTD.
TEMPOWER
AT12
3-POLE AIR CIRCUIT BREAKER
POLES: 3
OPERATIONAL VOLT.(UE): 690 VAC
RATED FREQUENCY: 50/60HZ
RATED CURRENT (IN): 1250 A
STANDARD : IEC 947-2
UTILIZATION CAT: B
RATED: UE WITH INST/ WITHOUT INST
BREAKING: 690V 50/50 KA
CAPACITY (ICU): 550-600V 50/50 KA
ICS=100% ICU 220-500V 65/50 KA
SHORT TIME WITH-: 1 SEC 50 KA
-STAND CURRENT(ICW): 3 SEC 45 KA
ATPS0017-B
AMB.TEMP.: 45℃
The Terasaki AT12 Tempower is a heavy-duty 3-pole air circuit breaker designed for high-current power distribution and protection in marine electrical systems. Rated at 1250A and 690VAC with a breaking capacity of 50kA, it is engineered to protect main and essential switchboard circuits from overload and short-circuit faults. As a core component within the Air Circuit Breaker category, this unit plays a critical role in maintaining continuity and safety across onboard power networks, where reliable fault interruption directly impacts vessel operability and crew safety.
Key Features
✓ Rated 1250A continuous current at 690VAC, 50/60Hz, with a short-circuit breaking capacity (Icu) of 50kA at 690V, compliant with IEC 947-2 Utilization Category B.
✓ Short-time withstand current (Icw) rated at 50kA for 1 second and 45kA for 3 seconds, providing robust protection during sustained fault conditions.
✓ Suitable for integration into main switchboards, emergency switchboards, and power distribution panels operating within the specified voltage range of 220–690VAC.
✓ Rated for ambient temperatures up to 45°C, making it appropriate for installation in engine room switchgear enclosures and similar thermally demanding environments.
✓ Replacement and servicing should be carried out with reference to the original panel configuration; compatibility with existing Terasaki Tempower installations should be confirmed prior to fitting.
Marine Applications
✓ Main and emergency switchboard protection on merchant vessels, tankers, bulk carriers, and offshore support vessels.
✓ Power distribution control in engine room electrical panels where high fault-level interruption is required.
✓ Generator incomer and bus-tie protection circuits aboard vessels with multiple generating sets.
✓ Essential services distribution panels protecting propulsion auxiliaries, cargo handling equipment, and HVAC systems.
✓ Retrofit and overhaul projects on vessels with existing Terasaki Tempower switchgear installations requiring like-for-like component replacement.
Why Marine Engineers Choose
The Terasaki AT12 Tempower is a well-established air circuit breaker trusted in marine switchgear for its high breaking capacity, IEC-compliant performance, and suitability across a wide voltage range — making it a dependable choice for both original equipment installations and planned maintenance replacements.
Ideal For
Merchant vessels, bulk carriers, tankers, container ships, offshore platforms, naval auxiliaries, and any commercial vessel requiring high-rated air circuit breaker protection within main or emergency power distribution systems.
Technical Support
Technical support is available for the Terasaki AT12 Tempower air circuit breaker, covering onboard installation guidance, fault diagnosis, and remote troubleshooting assistance. Enquiries related to panel integration and replacement procedures can be directed to our technical team.
