EMAS MKS1TM-25 - MKS Series 20.0-25.0A Motor Protection Switch
A DIN rail mounted manual motor protection switch (motor circuit breaker) from EMAS's MKS series, thermally calibrated over a 20.0-25.0A range to match the full load current of small single-phase or three-phase motors. This is the largest current rating in the MKS series.
Unlike a standard MCB, which just protects the wiring against overload and short circuit, a motor protection switch is designed specifically to protect the motor itself. It combines two separate protection mechanisms in one DIN rail device:
- Thermal overload protection - an adjustable dial lets you set the trip current to match the motor's actual full load amps (FLA), so the switch trips on a sustained overload but rides through the normal high inrush current of motor starting without nuisance tripping
- Fixed magnetic short-circuit protection - trips instantly at 12x the dial setting to clear a genuine short circuit or locked-rotor fault, rated to at least 6kA/400V
- Phase deficiency protection - detects loss of one phase on a 3-phase motor and trips before the motor can be damaged running single-phased
- Ambient temperature compensated, so the trip point doesn't drift with panel temperature
Suitable for:
- 35mm DIN rail mounting
- Direct-on-line (DOL) starting of small motors within this current range
- Retrofit motor protection upgrades where a simple MCB or fuse currently offers no overload/single-phasing protection
Technical Data
Frequently Asked Questions
How is this different from a normal MCB?
An MCB protects the cable, not the motor - it has one fixed trip curve and no allowance for motor starting current. This motor protection switch has an adjustable thermal dial matched to your motor's actual running current, plus separate fixed short-circuit and single-phasing protection - all in one device.
How do I set it up?
Set the dial to your motor's full load current (FLA), found on the motor's nameplate. The thermal element then protects against sustained overload while tolerating normal starting inrush.
Does it protect against a motor losing a phase?
Yes - phase deficiency (single-phasing) protection is built in, which a standard MCB does not provide.
Do you stock other current ranges?
Yes - see our MKS1TM-20 (16.0-20.0A) for the next size down.
Industry Applications
- Machine building & OEM panels - compact combined motor protection in place of separate MCB + overload relay
- Retrofit upgrades - adding proper motor protection to older panels that only have basic fusing
- Pump, fan and conveyor drives - direct-on-line motor circuits needing overload and single-phasing protection