CM9N series MCCBs are developed to meet international market demands. With a rated insulation voltage up to 1000V, they are suitable for AC 50/60Hz distribution networks with rated operating voltage up to 690V and current from 10A to 630A.
They provide reliable protection against overload, short circuit, and undervoltage, while also serving power distribution purposes. CM9N breakers feature high breaking capacity, short arcing, and support both vertical and horizontal installation.
Standard: IEC60947-2.
| Type | Operating and Installation Conditions |
| Altitude | ≤2000 m |
| Ambient Temperature | –5°C to +40°C ( +45°C for marine prod ucts) |
| Ambient Conditions | Resistant to damp air, mold, and radiation |
| Mounting Inclination | ≤22.5° |
| Mechanical Vibration | Operates reliably under normal ship vibration |
| Seismic Tolerance | Operates reliably under earthquake (4g) |
| Weather Protection | No direct exposure to rain or snow |
| Atmosphere Requirements | No explosive atmosphere or corrosive/conductive substances present in the ambient air. |
| CM9N | – | 125 | S | P | 3P |
| Model | Frame size | Breaking capacity Icu/lcs(kA) | Operation way | Poles | |
| MCCB | 125 250 400 630 | 125: 15/10 250: 25/18 400: 35/25 630: 35/25 | Default—handle direct operation; P—electric operation Z—rotating handle operation | 3P |
| 300 | 1 | 125A |
| Tripping mode and inner accessory | Application | Rated current(A) |
| The first number indicate release mode 2: only with the instantaneous release device 3: complex release Note: the last two numbers are attachment code (see attachment table) | 1: for distribution 2: for protecting the motor | Frame125: 10,16,20,32,40,50,63,80,100,125 Frame250: 100,125,140,160,180,200,225,250 Frame400: 250,300,315,350,400 Frame630: 400,500,630 |
| Frame Current(A) | 125 | 250 | 400 | 630 | |
| Type | CM9N-125S | CM9N-250S | CM9N-400S | CM9N-630S | |
| Number of poles | 3 | 3 | 3 | 3 | |
| Rated current In(A) | 10,16,20,25,32,40,50, 63,80,100,125 | 100,125,140,160,180, 200,225,250 | 250,315,350,400 | 400,500,630 | |
| Rated voltage Ue(V) | AC220/230V,400V,690V | AC220/230V,400V,690V | AC220/230V,400V,690V | AC220/230V,400V,690V | |
| Rated insulation voltage Ui(V) | AC1000V | AC1000V | AC1000V | AC1000V | |
| Short Circuit Breaking Capacity (kA)Icu/lcs | AC220V | 18-12 | 35/25 | 50/35 | 50/35 |
| AC400V | 15-10 | 25/18 | 35/25 | 35/25 | |
| AC690V | 4-3 | 6-4 | 8-6 | 8-6 | |
| Operating Circle Times | ON | 600 | 3000 | 2000 | 2000 |
| OFF | 900 | 7000 | 4000 | 4000 | |
| Electric operating device(MD) | ● | ● | ● | ● | |
| External drive handle | ● | ● | ● | ● | |
| Automatic release | Thermal electromagnetic type | Thermal electromagnetic type | Thermal electromagnetic type | Thermal electromagnetic type | |
| Rated Tripping Current(A) | Thermal-magnetic trip unit (ambient temperature +40°C) | Operating current of the magnetic trip unit(A) | |
| 1.05In(cold state) Non-operating time | 1.30In(hot state) operating time (h) | ||
| 10≤In≤63 | 1h | 1h | 6In±20%, 8In±20% 10In±20%, 7In±20% |
| 63<In≤630 | 2h | 2h | |
Note: The non-operating time of the motor protection circuit breaker is 2h at 1.0In; the operating current is 1.20In (hot state), and the operating time is 2h. The operating current of the electromagnetic release is 12In±20%.
When altitude is below 2000 m, performance is unaffected. Above 2000m, insulation and cooling derating applies. Correction factors are as follows:
| Altitude(m) | 2000 | 2500 | 3000 | 3500 | 4000 | 4500 | 5000 |
| Insulation Voltage Ui(V) | 800 | 728 | 728 | 664 | 664 | 616 | 616 |
| Impulse Withstand Voltage Uimp(kV) | 8 | 7 | 7 | 6.5 | 6.5 | 6 | 6 |
| Maximum Working Voltage Ue (V) | 690 | 690 | 690 | 660 | 660 | 600 | 550 |
| Thermal Rating In(A) at 40℃Ambient Temperature | 1.0ln | 0.98ln | 0.94In | 0.92In | 0.88ln | 0.86ln | 0.85In |
Note: At high altitudes, the breaking capacity should be reduced to 50%–75% of the rated voltage, depending on elevation. For details, please consult the technical department.
When ambient temperature exceeds 40 °C, overload protection may change slightly. The Ir setting should be corrected using the following I/Ir coefficients.
| Model | Ambient Temperature(℃) | ||||
| 40 | 45 | 50 | 55 | 60 | |
| CM9N-125 | 1 | 0.96 | 0.89 | 0.83 | 0.75 |
| CM9N-250 | 1 | 0.92 | 0.85 | 0.79 | 0.71 |
| CM9N-400/630 | 1 | 0.94 | 0.87 | 0.81 | 0.73 |
| Type | Overall size(mm) | |||||||||||
| W | L | H | A | B | W1 | L1 | L2 | H1 | H2 | D | D1 | |
| CM9N-125 | 75 | 130 | 84 | 112 | 25 | 26 | 117 | 75 | 56 | 66 | Φ4 | M6 |
| CM9N-250 | 106 | 165 | 101 | 126 | 35 | 35 | 147 | 97 | 69 | 78 | Φ5 | M8 |
| CM9N-400/630 | 150 | 257 | 150 | 194 | 44 | 48 | 224 | 156 | 102 | 112 | Φ14 | M10 |
