Non Combination Starter
A non-combination starter is a motor starter assembly that provides motor starting, control, and overload protection but does not include branch-circuit short-circuit and ground-fault protection or disconnecting means in the same enclosure. These protective functions must be provided by separate upstream devices such as fuses, a circuit breaker, or a motor circuit protector.
In shop-floor applications, non-combination starters are used in custom control panels, motor control centers (MCCs), and engineered equipment where upstream protection already exists at the feeder or panel level. They typically include a contactor and overload relay, and may include control devices, but depend on separate short-circuit and ground-fault protection upstream. Electricians and maintenance staff treat them as control and overload devices, not as complete isolation or protection points for the motor circuit. This affects lockout/tagout planning, troubleshooting, and replacement work because the starter alone does not make the circuit fully safe to work on.
- Assuming the starter provides full protection: A common error is treating a non-combination starter like a complete motor disconnect or protective assembly when the branch-circuit protective device is actually elsewhere.
- Undersized or miscoordinated upstream protection: If the separate breaker, fuse, or motor circuit protector is not properly selected for the motor and feeder, the non-combination starter will not be adequately protected against short-circuit or ground-fault events.
- Poor lockout practice: Workers may isolate only at the starter bucket or contactor and fail to verify the actual upstream disconnecting means, which is especially problematic under WorkSafeBC lockout expectations.
Does a non-combination starter disconnect power safely for maintenance?
Not by itself. It usually controls the motor and trips on overload, but the actual branch isolation and short-circuit protection come from separate upstream devices.
Why choose a non-combination starter instead of a combination starter?
It is often used when the panel or MCC already has coordinated upstream protection, making a separate built-in disconnect or protective device unnecessary or duplicative.
What components are normally inside a non-combination starter?
Commonly a contactor and overload relay, with control circuitry; the short-circuit and ground-fault protective device is external.