Complementary
Network frequency	50/60 Hz
[Ue] rated operational voltage	380...415 V AC 50/60 Hz; 125 V DC;
Magnetic tripping limit	8 x In +/- 20 %
[Ics] rated service breaking capacity	52.5 kA 75 % conforming to EN/IEC 60947-2 - 110...130 V AC 50/60 Hz; 27 kA 75 % conforming to EN/IEC 60947-2 - 220...240 V AC 50/60 Hz; 6.75 kA 75 % conforming to EN/IEC 60947-2 - 380...415 V AC 50/60 Hz; 36 kA 100 % conforming to EN/IEC 60947-2 - 60 V DC; 36 kA 100 % conforming to EN/IEC 60947-2 - 125 V DC
[Ui] rated insulation voltage	690 V AC 50/60 Hz conforming to EN/IEC 60947-2
[Uimp] rated impulse withstand voltage	8 kV conforming to EN/IEC 60947-2
Control type	Manual tripping test; Toggle
Local signalling	ON/OFF indication; Trip indicator
Mounting mode	Clip-on
Mounting position	Vertical
Mounting support	35 mm symmetrical DIN rail
9 mm pitches	3
Height	103 mm
Depth	81 mm
Width	27 mm
Net weight	0.24 kg
Mechanical durability	20000 cycles
Electrical durability	5000 cycles
Provision for padlocking	Padlockable
Locking options description	Integrated padlocking
Connections - terminals	Tunnel type terminals16…70 mm² rigid; Tunnel type terminals10…50 mm² flexible
Wire stripping length	20 mm
Tightening torque	6 N.m
Earth-leakage protection	Without
Contact position indicator
Comb busbar and distribution block compatibility
Contractual warranty
Warranty (in months)	18
Environment
IP degree of protection	IP20 conforming to IEC 60529
IK degree of protection	IK05 conforming to EN/IEC 62262
Pollution degree	3 conforming to IEC 60947-2
Overvoltage category	IV
Tropicalisation	2 conforming to IEC 60068-1
Relative humidity	95 % at 55 °C
Ambient air temperature for operation	-30…70 °C
Ambient air temperature for storage	-40…70 °C
Logistical informations
Country of origin	FR
Main
Range	Acti9
Product name	Acti9 NG125
Product or component type	Miniature circuit-breaker
Device short name	NG125H
Device application	Distribution
Poles description	1P
Number of protected poles	1
[In] rated current	80 A at 40 °C
Network type	DC; AC
Trip unit technology	Thermal-magnetic
Curve code	C
Breaking capacity	36 kA Icu at 220...240 V AC 50/60 Hz conforming to EN/IEC 60947-2; 36 kA Icu at 12 V DC conforming to EN/IEC 60947-2; 70 kA Icu at 110...130 V AC 50/60 Hz conforming to EN/IEC 60947-2; 36 kA Icu at 125 V DC conforming to EN/IEC 60947-2; 25 kA Icu at
Utilisation category	Category A conforming to IEC 60947-2
Suitability for isolation	Yes conforming to IEC 60947-2
Standards	EN/IEC 60947-2
Packing Units
Unit Type of Package 1	PCE
Number of Units in Package 1	1
Package 1 Height	3.2 cm
Package 1 Width	8.1 cm
Package 1 Length	11 cm
Package 1 Weight	256 g
Unit Type of Package 2	BB1
Number of Units in Package 2	12
Package 2 Height	9.1 cm
Package 2 Width	11.9 cm
Package 2 Length	36 cm
Package 2 Weight	3.161 kg
Unit Type of Package 3	S03
Number of Units in Package 3	72
Package 3 Height	30 cm
Package 3 Width	30 cm
Package 3 Length	40 cm
Package 3 Weight	19.453 kg

The Acti9 NG125H circuit breaker from Schneider Electric is a 1-pole line protection switch designed for distribution in electrical installations. It protects circuits against overload currents and short-circuit currents and is part of the Acti9 series. The device features a thermomagnetic tripping technology that enables precise response to thermal overloads and magnetic short-circuit currents. The C curve defines the tripping characteristic, with the magnetic tripping threshold at 8 times the rated current. The rated current is 80 A at an ambient temperature of 40 °C. The operating voltage includes 380–415 V AC and 125 V DC, with a rated insulation voltage of 690 V AC. The device complies with the EN/IEC 60947-2 standard and is designed for usage category A, enabling application in distribution systems with defined protection requirements.

Applications

The NG125H is suitable for use in industrial and commercial electrical installations, particularly in distribution switchgear, where reliable circuit protection is required. The IP20 protection rating ensures protection against finger contact and solid foreign objects, but not against splashing water or dust. The IK05 protection rating safeguards against mechanical impacts such as light shocks. The operating ambient temperature ranges from -30 °C to 70 °C, with storage possible down to -40 °C. The relative humidity is up to 95 % at 55 °C. The overvoltage category IV and pollution degree 3 indicate application in environments with high electrical stress and pollution risks.

Functions and Equipment in Detail

The device features a contact position indicator that visually signals the contact position (ON/OFF). A red mechanical indicator on the front shows the tripping status. A manual trip test via a test button allows checking the tripping function without current flow. Mounting is on a 35 mm symmetrical DIN rail, with vertical mounting position. The integrated interlock enables secure locking of the switch, for example during maintenance work. Connections are made via tunnel terminals designed for solid conductors from 16 to 70 mm² and flexible conductors from 10 to 50 mm². The wire stripping length is 20 mm, and the required tightening torque is 6 Nm.

Technology Explained Simply

The thermomagnetic tripping technology combines a thermal and a magnetic tripping mechanism. The thermal part responds to sustained overloads by activating the tripping mechanism through thermal expansion. The magnetic part reacts immediately to high short-circuit currents to ensure rapid protection. The breaking capacity varies by voltage: 36 kA Icu at 220–240 V AC, 70 kA Icu at 110–130 V AC, 36 kA Icu at 125 V DC, and 25 kA Icu at 380–415 V AC. The rated service breaking capacity (Ics) is, for example, 27 kA at 220–240 V AC. The mechanical life is 20,000 cycles, and the electrical life is 5,000 cycles.

Compatibility and Accessories

Additional stackable auxiliary modules extend the switch’s functionality. These include overload release units (e.g. MX 230–415 V AC), undervoltage release units (e.g. MN 230–240 VAC), auxiliary switches (e.g. 2W 240 VAC 6 A), as well as connection covers and interlock elements. These modules can be added according to application requirements to realize specific protection or signaling functions. The cable lugs and multi-connection terminals are designed for connections with different conductor cross-sections.

Mounting and Installation

The switch is mounted by clipping onto a 35 mm DIN rail. Mounting is in vertical position, with power supply possible from both top and bottom. The snap-action switching ensures wear-free switching of contacts. The integrated interlock enables secure locking of the switch. Dimensions are 103 mm (height), 81 mm (depth), and 27 mm (width), with a product weight of 0.24 kg.

Advantages in Operation

The NG125H offers high reliability through thermomagnetic tripping technology and robust construction. Clear signaling of switch and tripping positions simplifies maintenance and diagnostics. Compatibility with various accessory modules allows flexible adaptation to specific requirements. Compliance with the EN/IEC 60947-2 standard and VDE certification of the series guarantee the safety and quality of the device. The integrated interlock supports safety during maintenance work.