SELECTION COMPARISON
Overview
Schneider's low-voltage circuit breakers form a progressive product line by current range: iC65 covers conventional current for terminal distribution, C120H continues to the higher current miniature circuit breaker segment, and ComPacT NSX enters the molded case circuit breaker segment.
The most common problem in actual procurement is the selection around 63A - all three series may appear at this current point, but the applicable scenarios are completely different.
Current range connection table
| Series | type | Common current range | typical applications |
|---|---|---|---|
| Acti9 iC65 | Miniature circuit breaker MCB | 6A – 63A | Terminal circuits, lighting, sockets, low power equipment |
| C120H | High current miniature circuit breaker | 63A – 125A | Larger terminal circuits and distribution box incoming wires |
| ComPacT NSX | Molded case circuit breaker MCCB | 100A – 630A (by frame size) | Distribution cabinet main circuit, motor circuit, feeder protection |
| MasterPact MTZ | Air circuit breaker ACB | 630A or above | Main incoming line, bus coupler, high current power distribution |
How to choose near 63A
If it is a terminal circuit (lighting, socket, small equipment), iC65 can be used for 63A, with small installation width and low cost.
If it is a distribution box incoming line or a circuit with concentrated loads, choose C120H for the 63A–125A section, which retains modular installation but can withstand larger currents.
If you need adjustable protection settings, higher breaking capacity, or the possibility of subsequent expansion to more than 100A, choose NSX directly.
The molded case circuit breaker can be equipped with an electronic trip unit, and the protection characteristics are adjustable and suitable for the main circuit.
The judgment is based not only on current figures, but also on: breaking capacity requirements, whether adjustable protection is required, installation method (rail or fixed plate) and short-circuit current level.
Common Pitfalls
Select according to current only, ignoring breaking capacity.
Breaking capacity must be confirmed in combination with IEC standards and actual working voltage. The same model has different breaking values at different voltages.
Consider the NSX's frame current as rated current.
For example, NSX100 is a frame specification, and the actual rated current is determined by the trip unit. The same frame can be equipped with different rated currents.
Ignore trip unit type.
TM-D is a thermal magnetic type, while MicroLogic is an electronic type. The protection characteristics and adjustable range are completely different, so they must be clearly stated when purchasing.
Frequently Asked Questions
Is NSX100 just 100A?
No. NSX100 represents the frame specification. The actual rated current is determined by the configured trip unit. The same frame can have different configurations from 16A to 100A. Purchases must provide the complete ordering code.
Are the C120H and iC65 interchangeable?
The installation method at the overlap point 63A is similar, but the breaking capacity and structure are different, and direct interchange is not recommended. It should be selected according to the actual short-circuit current level and loop importance.
How to choose between electronic and thermal magnetic trip units?
The thermomagnetic type (TM-D) has a simple structure and low cost, and is suitable for circuits with fixed protection requirements; the electronic (MicroLogic) protection has adjustable settings and high precision, and is suitable for main circuits and occasions that require selective cooperation.
How to confirm the complete ordering code?
It is necessary to confirm the frame, number of poles, trip unit type, rated current, breaking capacity level and installation method. You can provide a front view photo or nameplate of the existing circuit breaker and we will assist in verification.
Need help confirming a part number or application?
Send the complete part number, BOM, nameplate or product photos. Documents and images can be shared through WhatsApp, Telegram or WeChat.
