IMO UL Approved Miniature Circuit Breakers
February 3, 2026
IMO Precision Controls – 50 Years of Excellence
Their history is one of innovation. Whether it is the first ever BT Type 47 Approved relay or the first ever compact AC inverter for motor speed control, IMO has always been focused on breaking barriers. With rigorous standards of development, reliability testing and production control, complemented by all the most relevant independent approvals, IMO remains the no-compromise choice.
Continuing IMO’s path of innovation is their range of UL Approved Miniature Circuit Breakers. With an already impressive range of VDE and SEMKO (with RCM in Australia) approved MCBs, RCDs and Isolating Switches, the new series of UL 489 and UL 1077 approved MCBs are the final piece in their jigsaw of comprehensive circuit protection against electrical threats including overloads, short circuits and earth leakages.
With the addition of these exciting new products, perhaps it’s time that you optimise your control panel?
UL 489 Approved MCB
Designed for protection of electrical installations against overcurrent in the branch circuit, whilst also allowing motor branch circuit protection, this high performing range of DIN rail mountable MCBs have been manufactured in accordance with UL 489.
- Available from 0.5 Amps to 63 Amps
- Thermo-magnetic overcurrent protection
- 10kA short circuit protection
- RoHS compliant
- B, C & D Type tripping curves
- Contact position indicator
UL 489 Listed Performance
The entire range of UL 489 approved MCBs feature design developments which incorporate a protective contact position indicator and a high performing, high quality switching mechanism for extended life and reliability.
UL 489 approved MCBs are required to pass stringent short circuit and switching test requirements, along with having larger clearances and electrical spacings.
IMO’s range is available in single, double or triple poles, with current ranges from 0.5 Amps to 63 Amps, with the choice of B, C & D tripping curves.
A full range of complimentary accessories are also available from stock, including auxiliary contacts, shunt trips, undervoltage trips, alarm contacts and locking devices.
Branch Circuit Protection
Circuit protection at panel level requires higher short circuit protection (interrupting capacity), and as such UL 489 approved MCBs must pass a series of calibration, overload, endurance and short circuit tests that are considerably more rigorous than UL 1077.
Part of achieving UL 489 compliance is the addition of an extension to the body moulding in between each contact for increased isolation.
UL 489 approved MCBs can protect multiple devices at a time, such as an entire control panel. Classified for branch circuit use, they can also be used for outlets or for feeding utilization equipment.
UL 489 approved MCBs can act as the final overcurrent device dedicated to protecting the branch circuits and outlets. It doesn’t require the use of an additional backup overcurrent device.
UL 489 MCB Applications
Suitable for branch circuit protection whilst providing thermo-magnetic overcurrent protection in applications from 0.5 Amps to 63 Amps.
Applications where UL 489 approved MCBs are used:
- Motor Controls
- Control Panels
- Switchboards
- in virtually
- every industry!
UL 489 MCB – 10kA
UL File No.: E495936 – Approved UL 489 MCB 0.5 Amps to 63 Amps, available in either B*, C or D type tripping curves.
UL Approved MCB Accessories
IMO’s comprehensive selection of accessories can be used with both UL 489 and UL 1077 MCBs.
For further information please visit www.imopc.com or contact IMO directly.
Related Product
IMO Panel Product Range
IMO’s Panel product range continues to deliver innovation and efficiency worldwide and is where technology and expertise in engineering come together. IMO’s Panel range has been specifically designed to meet the demanding needs of today’s panel builders and engineers whose requirements can range from a simple DIN rail terminal through to a complete panel solution.
