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Motorised Change Over Switches (OTM)
Source genuine ABB Motorised Change-Over Switches (OTM) from Hagar, supported by local South African stockholding.
ABB OTM motorised change-over switches provide safe and dependable switching between two power sources, making them ideal for utility-to-generator changeover, standby power and automated AMF/ATS applications. Available in 3-pole and 4-pole configurations, their mechanically interlocked design prevents simultaneous connection of independent power sources.
Integrated with an automatic transfer controller and appropriate Moulded Case Circuit Breakers (MCCBs), OTM switches provide a robust solution for commercial, industrial and critical backup-power systems.
ABB change-over switches feature built-in mechanical and electrical interlocks to guarantee that utility power and generator power can never cross-connect under load.
ABB OTM Motorised Change-Over Switches: Motor-driven transfer switches built for automated AMF (Automatic Mains Failure) panels and building management systems.
ABB OT Manual Change-Over Switches: High-durability, manual knife-blade disconnect switches operated via door-mounted rotary handles.
4-Pole Neutral Isolation: Full inventory of 4-pole configurations ensuring complete neutral-line isolation during generator switchovers to satisfy SANS installation regulations.
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Frequently Asked Questions
Can ABB OTM motorized change-over switches be integrated into automated AMF panels?
Yes. ABB OTM motorized change-over switches are fully compatible with Automatic Mains Failure (AMF) controllers and building management systems. They feature built-in dual interlocks (mechanical and electrical) to ensure a safe, reliable transfer between grid power and backup generator power without phase collision.
How do I correctly size an ABB change-over switch for a standby generator?
Change-over switches must be sized based on the maximum continuous current (Amps) of the electrical supply, not just the generator’s kVA rating. For example, a 100kVA three-phase generator outputs roughly 144A per phase, meaning an ABB switch rated for at least 160A or 200A should be selected to allow an appropriate safety margin.
What are the main benefits of using a manual OT switch over a motorized OTM switch?
Manual OT switches are highly cost-effective, require zero control wiring, and are ideal for installations where a human operator will manually start and transfer over to a backup generator. Motorized OTM switches are necessary for critical facilities requiring automated power restoration within seconds of a utility grid failure.
Are ABB change-over switches suitable for use as main isolation switches?
Yes. ABB OT and OTM change-over switches are designed as knife-blade type disconnectors. They provide positive contact indication and full isolation characteristics in accordance with international IEC 60947-3 standards, meaning they can safely serve as the main incoming isolation point for a facility.
