KFM3XL Series Residual Operated Current Molded Case Circuit Breaker

Overview & scope

The KFM3XL series residual current operated molded case circuit breakers belong to the KFM3X family. Rated insulation voltage is 1000 V; they apply to AC 50/60 Hz circuits with rated operational voltage 400 V and rated operational current up to 800 A, for infrequent conversion and infrequent motor starting.

They combine overload, short circuit and undervoltage protection with residual current (earth leakage) protection — indirect contact protection for persons and protection against fire hazards from persistent earth-fault currents not covered by overcurrent protection.

Residual Current MCCB

Design & features

Residual current protection with adjustable characteristics; schemes for AC 690 V residual current protection available.
Works with the KFLJ5 residual current relay and matching current transformer (3P or 4P breakers).
Fast closing / fast breaking mechanism; repulsion-assisted contact system; zero or short arcing distance.
Draw-out device available for 400 / 800 frames only.
PV grid-connection dedicated version available.
Suitable for plateau, high/low temperature and salt-fog environments.

Key technical data

Key technical data	Value	Source
Frame sizes	100 / 160 / 250 / 400 / 630 / 800	P58
Rated operational voltage Ue	AC400V	P57
Rated current In	Up to 800A	P57
Residual current protection	Residual current (earth leakage) protection; indirect contact protection	P57
Draw-out device	Available for KFM3XL-400 and KFM3XL-800 only	P71

The full Icu / Ics / Icm matrix per voltage level is available from the original catalog and on request. Values below are summary figures verified against the catalog.

Product gallery

Outline & installation

Dimension drawings for this series are being prepared from the original artwork. Contact us to request them.

Frame / model list

KFM3XL-100 KFM3XL-160 KFM3XL-250 KFM3XL-400 KFM3XL-630 KFM3XL-800

Frame sizes	Note	Source
KFM3XL-100	—	P57–P59
KFM3XL-160	—	P57–P59
KFM3XL-250	—	P57–P59
KFM3XL-400	Draw-out device available	P57–P59
KFM3XL-630	—	P57–P59
KFM3XL-800	Draw-out device available	P57–P59

Accessories

Undervoltage release (incl. PV module)

Includes the PV grid-connection module: undervoltage trip 70%–20% Un, loss-of-voltage trip below 20% Un, overvoltage protection above 135% Un, trip delay adjustable 0–10 s.

Source: P21 / P45 / P67

Shunt release

DC24V / DC110V / DC220V; reliable trip between 70%–110% rated control voltage; 50 cm lead as standard, 100/150 cm optional.

Source: P8 / P38 等

Auxiliary & alarm contacts

Up to 10 NO + 10 NC independent contacts on KFW3; three-position and ready-to-close contacts optional.

Source: P14–P17

Electric operating mechanism

New-generation DC3 mechanism; enables automatic closing with voltage check in PV grid-connection schemes.

Source: P23 / P47 / P69

Communication module

Status upload for thermo-magnetic breakers once the module is fitted.

Source: P25 / P73

Draw-out device

Available for 400 / 800 frames only. KFW3 offers a draw-out version natively (connected / test / disconnected).

Source: P24 / P48 / P71

Accessories →

Ordering information

Ordering codes in the catalog (P76). Specify frame, rated current, poles, residual-current settings and accessory codes.