Don’t know the model number of your old MCB? Learn how to identify the right miniature circuit breaker by appearance, width, terminal type, and mounting. Perfect for buyers in Southeast Asia, Africa, and the Middle East.
No Model Number? No Problem. Match by Sight.
Many electrical buyers face the same problem: you have an old miniature circuit breaker in hand, but the model number is faded or missing. Ordering the wrong replacement wastes time and money. The good news is that you don’t need a model number to find the right MCB. You just need to look at three things: appearance, width, and terminal type.
Step 1 – Check the Width
The most important measurement is width. Standard miniature circuit breakers have a width of 18mm per pole. That means a 1P MCB is 18mm wide, a 2P is 36mm, a 3P is 54mm, and a 4P is 72mm. Measure your existing device. If it matches these dimensions, it will fit on a standard 35mm DIN rail – the industry standard for low-voltage distribution boards in Southeast Asia, South America, and the Middle East.
Step 2 – Look at the Appearance
Different series have different shapes, handle styles, and terminal designs. For example, the HX1, HX2, HX3, and HX5 series from Hongxi Electric look similar but have different breaking capacities. HX2 and HX5 offer 10kA breaking capacity, while HX3 offers 6kA. By comparing your old MCB’s appearance to product photos online, you can quickly narrow down the series.
Step 3 – Match the Terminal Type
Terminals matter. Some MCBs use pin-type terminals for busbar connection, while others use lug-type terminals for cable connection. Check your existing unit. If the terminal has a small round hole for a pin, you need a pin-type MCB. If it has a larger square opening for a screw-clamped cable, you need a lug-type. Using the wrong terminal type will make installation difficult or impossible.
Step 4 – Confirm the Current and Curve
Once you have identified the correct series, width, and terminal type, the final step is choosing the right rated current (6A, 10A, 16A, up to 63A) and trip curve (B, C, or D). For most general applications, the C curve is the standard choice. If you are unsure, send us a photo of your old MCB – we can help you match it within 24 hours.
Need Help Matching Your MCB?
At Hongxi Electric, we help buyers across Africa, Europe, and Southeast Asia find the right electrical components by appearance and size. No model number? No problem. Send us a photo, and we will identify the match for you.
