When a 25A Three-Phase Feeder Keeps Tripping: The iC60N 3P C25 Answer
A panel builder was commissioning a three-phase distribution board. The 25A feeder kept dropping out under normal motor start-up surges. The culprit was a breaker with the wrong trip curve. The fix was the Schneider Electric iC60N 3P C25, a 25A three-pole miniature circuit breaker from the Acti9 iC60 series with a C-curve trip profile. That curve tolerates brief inrush currents while still clearing genuine faults.
What the iC60N 3P C25 Delivers
This device protects three-phase circuits rated up to 25A at 400V AC. Its thermal-magnetic trip unit combines a C-curve magnetic threshold of 8×In ±20% with thermal overload protection. The 6 kA breaking capacity at 230/400V means it safely interrupts short-circuit currents up to that level. It carries EN/IEC 60898-1 and EN/IEC 60947-2 approvals, so it suits both residential distribution and industrial control panels.
Technical Specifications at a Glance
| Parameter | Value |
|---|---|
| Poles | 3P |
| Rated current | 25A |
| Trip curve | C (magnetic trip 8×In ±20%) |
| Breaking capacity | 6 kA @ 230/400V |
| Rated voltage | 400V AC |
| Standards | EN/IEC 60898-1, EN/IEC 60947-2 |
| Operating temperature | -35 to 70 °C |
| Mounting | 35 mm DIN rail |
| Mechanical life | 20,000 cycles |
| Electrical life | 10,000 cycles |
| Dimensions (H×W×D) | 85 × 54 × 78.5 mm |
| Weight | 0.375 kg |
Why the C-Curve and 6 kA Rating Matter
The C-curve magnetic trip at 8×In ±20% handles the inrush of small motors and transformers without nuisance tripping. A B-curve device would trip too easily on start-up. Meanwhile, the 6 kA breaking capacity gives you a solid safety margin in most commercial and light industrial boards. The 25A rating fits three-phase feeders, sub-distribution circuits, and small machine panels. The 400V AC rated voltage matches standard three-phase supplies.
Where This Breaker Fits
Three-phase motor feeders – The 25A rating and C-curve manage start-up surges on small pumps, fans, and conveyors. The 6 kA breaking capacity protects the feeder against short circuits.
Commercial distribution boards – Panel builders use the iC60N 3P C25 for three-phase sub-circuits feeding lighting, HVAC, or socket outlets. The 35 mm DIN rail mount simplifies installation.
Control panel retrofits – When upgrading an older board, the compact 85 × 54 × 78.5 mm footprint and 0.375 kg weight make replacement straightforward. The 20,000 mechanical and 10,000 electrical cycle ratings support long service intervals.
Installation and Setup
Mount the breaker on a standard 35 mm DIN rail. Confirm the supply voltage does not exceed 400V AC. Tighten terminals to the torque specified in the manufacturer’s documentation. Verify the C-curve suits the load’s inrush profile before energising. The operating temperature range of -35 to 70 °C covers most indoor and sheltered outdoor enclosures. Always follow local wiring regulations and the manufacturer’s instructions.
Maintenance and Reliability
The iC60N 3P C25 has no user-serviceable internal parts. Inspect terminals periodically for tightness and signs of overheating. Exercise the breaker manually during routine maintenance to confirm smooth operation. Keep the enclosure free of dust and moisture. The 20,000 mechanical cycles and 10,000 electrical cycles indicate a long service life under normal conditions. Replace the device if it trips without a clear fault or shows physical damage.
Compatibility and Integration
The Acti9 iC60 series shares a common 35 mm DIN rail footprint with many Schneider distribution components. This simplifies panel layout and future expansion. The device works with standard three-phase supplies at 400V AC. It meets EN/IEC 60898-1 and EN/IEC 60947-2, so it integrates into panels designed to those standards. Check coordination with upstream and downstream devices during design.
Selection Checklist Before You Buy
Confirm the following before ordering:
- System voltage does not exceed 400V AC
- Load current stays within the 25A rating
- C-curve matches the load’s inrush characteristics
- Panel uses 35 mm DIN rail
- Required breaking capacity does not exceed 6 kA
SpareTechPLC supplies the iC60N 3P C25 and can confirm current lifecycle status. The Acti9 range remains active in production as of the last verification.
Frequently Asked Questions
Q: What does the C-curve mean on this breaker?
A: The C-curve magnetic trip operates at 8×In ±20%. It tolerates brief inrush currents from small motors and transformers without tripping.
Q: Can I use this breaker on a single-phase circuit?
A: It is a 3P device rated for 400V AC three-phase systems. For single-phase applications, select a breaker rated for that configuration.
Q: What is the breaking capacity of the iC60N 3P C25?
A: It provides 6 kA breaking capacity at 230/400V, verified to IEC 60898-1.
Q: How many electrical operations can it handle?
A: The data sheet rates electrical life at 10,000 cycles and mechanical life at 20,000 cycles.
Q: Is this product still in production?
A: Yes. The Acti9 iC60 range is listed as active. Contact SpareTechPLC to confirm availability.
