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 C
MADE IN JAPAN
The Terasaki AT12 TemPower is a heavy-duty 3-pole air circuit breaker engineered for high-current protection and power distribution control in demanding marine electrical systems. Rated at 1250A and 690VAC, it provides reliable overcurrent, overload, and short-circuit protection within main switchboards, distribution panels, and power management systems onboard. As a critical component in the air circuit breaker category, it plays a central role in safeguarding vessel electrical infrastructure and maintaining continuous power availability during operation.
Key Features
✓ Rated at 1250A continuous current with an operational voltage of 690VAC at 50/60Hz, conforming to IEC 947-2 standards for low-voltage switchgear and controlgear.
✓ High breaking capacity of 50/50 kA at 690V, with ICS equal to 100% ICU, ensuring full-rated short-circuit performance across the operational voltage range.
✓ Short-time withstand current (ICW) rated at 50 kA for 1 second and 45 kA for 3 seconds, providing robust protection in demanding fault conditions.
✓ Utilisation Category B classification indicates suitability for applications requiring both instantaneous and time-delayed tripping, with configurations available with or without instantaneous release.
✓ Designed for ambient temperatures up to 45°C, making it well suited to engine room switchboard environments typical of marine installations; manufactured in Japan to Terasaki’s established quality standards.
Marine Applications
✓ Main and emergency switchboard installations on commercial cargo vessels, tankers, and bulk carriers where high-current circuit protection is essential.
✓ Power distribution panels on offshore support vessels, platform supply vessels, and anchor handling tugs requiring robust fault interruption capability.
✓ Generator incomer and bus-tie breaker positions within marine power management systems on passenger ferries and cruise ships.
✓ Propulsion and thruster control distribution boards on dynamic positioning vessels where power continuity and fault isolation are operationally critical.
✓ Auxiliary machinery switchboards on naval auxiliaries, dredgers, and heavy lift vessels operating under variable load and fault exposure conditions.
Why Marine Engineers Choose
Marine engineers specify the Terasaki AT12 TemPower for its proven high breaking capacity, full ICS rating, and robust short-time withstand performance — characteristics that are essential for protecting shipboard electrical systems against severe fault conditions while maintaining operational reliability.
Ideal For
Cargo vessels, tankers, bulk carriers, offshore support vessels, passenger ferries, cruise ships, dynamic positioning vessels, dredgers, and heavy lift vessels requiring high-performance air circuit breaker protection in main or auxiliary switchboard applications.
Technical Support
Technical support is available for this Terasaki AT12 TemPower air circuit breaker, covering onboard installation guidance, repair assistance, and remote troubleshooting. Contact our team for help with integration into existing switchboard configurations or fault diagnosis support.
