Data is derived from the official manual of Chint NM1 series, all units are in mm, and the accuracy is subject to the physical product:
- Core Mounting and Overall Dimensions (3-القطب, front wiring, manual operation)
| المعلمة | قيمة | وصف |
| الأبعاد الشاملة (W×D×H) | 243×270×448 | Width W=243, Depth D=270, Height H=448 |
| Mounting Hole Spacing | 200 | Center distance between two holes on the mounting plate |
| Mounting Hole Diameter | Φ10 | Suitable for M10 bolts |
| Mounting Plate Thickness | ≥5 | It is recommended to use a mounting plate with a thickness of ≥5mm |
| Arc Flash Distance | ≤100 | Sufficient arc flash space shall be reserved |
| Handle Height | 172 | Height from the top of the handle to the mounting plate |
- Dimensional Differences for Different Wiring Methods
| طريقة الأسلاك | Core Dimensional Change | ملاحظات |
| Front Wiring | Width 243, Depth 270, Height 448 | Default standard dimension |
| Rear Wiring | Depth increased to about 280 | Matching rear wiring board is required, mounting hole positions remain unchanged |
| Plug-in Type | Depth increased to about 290 | Suitable for plug-in base, mounting hole positions remain unchanged |
ثالثا. Key Points for Mounting and Fastening
- Mounting method: Vertical or horizontal mounting is supported; the mounting plate shall be flat and firm to ensure good heat dissipation.
- Tightening torque: M12 bolts for main wiring terminals, the recommended tightening torque is 28N·m to ensure reliable wiring.
- Bus bar adaptation: For a rated current of 800A, it is recommended to use bus bars of ≥240mm² to meet the current-carrying capacity and heat dissipation requirements.
- Space reservation: An arc flash distance of ≥100mm shall be reserved around to avoid potential safety hazards caused by short-circuit electric arcs.
Cross-Brand Model Comparison Table for Chint NM1-800H/3300-800A
The following comparison is based on the core parameter matching of 3-pole, 800A rated current, H-grade breaking capacity (50kA@400V), thermomagnetic tripping (combined tripping), no accessories. Data is derived from the official samples of various brands. Please check the detailed technical parameters and mounting dimensions before replacement.
- Corresponding Models of Mainstream International Brands
| s | | | |
| ماركة | النموذج المقابل | Key Parameter Matching | Replacement Notes |
| شنايدر | NSX800H TMD 800 3P3D | • 3-pole, 800أ | 1. Mounting dimension difference: NSX800 (Width 243mm, Depth 270mm, Height 448mm), consistent with Chint |
| NS800H 3P 800A | • H-grade breaking capacity (50kA@400V) | 2. Tripping curve shall match the protection requirements of the original system |
| • TMD thermomagnetic tripping | 3. توافق الملحقات: Interfaces of auxiliary/shunt trip devices are different |
| ايه بي بي | Tmax T6N 800/3P 800A | • 3-pole, 800أ | 1. Slightly larger mounting depth (about 280mm) |
| T6H 800/3P 800A | • N-grade (50ال)/H-grade (70ال) كسر القدرة | 2. Confirm that the tripper type is thermomagnetic (TMD) |
| • Thermomagnetic tripping unit | 3. Bus bar wiring methods may vary |
| سيمنز | 3VT800N-3NF00-800A | • 3-pole, 800أ | 1. Overall dimensions: Width 240mm, Depth 265mm, Height 440mm (slightly different) |
| 3VT800H-3NF00-800A | • N-grade (50ال)/H-grade (70ال) كسر القدرة | 2. Operating mechanism is different from Chint, need to confirm the mounting space |
| • Thermomagnetic tripping | 3. Protection characteristics shall be consistent with the original system |
| Eaton | IZM91H3-U800 | • 3-pole, 800أ | 1. Breaking capacity is optional; priority is given to N-grade (50ال) to match Chint H-grade |
| IZM91N3-U800 | • H-grade (70ال)/N-grade (50ال) كسر القدرة | 2. Terminals specifications are different, need to adapt to bus bars |
| • Thermomagnetic tripping | |
- Corresponding Models of Well-Known Domestic Brands
| ماركة | النموذج المقابل | Key Parameter Matching | Replacement Notes |
| تشانغشو التبديل | CM1-800H/3300-800A | • 3-pole, 800أ | 1. Fully compatible mounting dimensions (same as Chint NM1 series) |
| CM3-800H/3300-800A | • H-grade breaking capacity (50kA@400V) | 2. Slight difference in tripper sensitivity, on-site commissioning is required |
| • Thermomagnetic combined tripping | 3. High accessory universality, direct replacement is available |
| DELIXI | CDM3-800H/3300-800A | • 3-pole, 800أ | 1. Consistent overall dimensions: Width 243mm, Depth 270mm, Height 448mm |
| CDM3S-800H/3300-800A | • H-grade breaking capacity (50kA@400V) | 2. Obvious price advantage and high cost performance |
| • Thermomagnetic tripping | 3. Slight difference in breaking capacity curve from Chint |
| Shanghai People’s SW | RMM1-800H/3300-800A | • 3-pole, 800أ | 1. Compatible mounting dimensions |
| • H-grade breaking capacity (50kA@400V) | 2. Tripper type is exactly the same as Chint |
| • Thermomagnetic combined tripping | 3. Comprehensive after-sales service network coverage |
| Chint Upgraded Replacement | NXM-800H/3300-800A | • 3-pole, 800أ | 1. Upgraded model of NM1 series with improved performance |
| • H-grade breaking capacity (50kA@400V) | 2. Fully consistent mounting dimensions for direct replacement |
| • Thermomagnetic tripping | 3. Optimized protection characteristics, more suitable for modern power distribution systems |
ثالثا. Core Technical Points for Replacement
- Mandatory Matching Items for Key Parameters
| المعلمة | Matching Requirement | Risk of Mismatch |
| رقم القطب | Must be 3P | Single-phase/three-phase unbalance and protection failure |
| التصنيف الحالي | Must be 800A | Overload protection failure and line overheating |
| كسر القدرة | ≥50kA@400V | Failure to break reliably in case of short-circuit fault, leading to arc accidents |
| Tripper Type | Must be thermomagnetic combined tripping | No overload protection (magnetic tripping only) or mismatched protection characteristics |
| Mounting Dimensions | W×D×H≈243×270×448mm | Inability to install or impact on adjacent equipment |
- Replacement Operation Steps
- Cut off the power and test for no voltage to ensure safety.
- Remove the original circuit breaker and record the wiring method and phase sequence.
- Install the new circuit breaker and fasten according to the manufacturer’s torque requirements (28N·m for M12 bolts of main terminals).
- Check the tripper settings (long-delay current 800A, instantaneous multiple 10-12 مرات).
- Power on for testing and check the closing/opening actions and protection functions.
- Accessory Replacement Suggestions
| Original Accessory | Replacement Solution | ملحوظات |
| الاتصال المساعد | Auxiliary contact of the same specification from the corresponding brand | Terminal definitions may be different |
| Shunt Trip Device | Shunt trip device matching the new circuit breaker | Control voltage must be consistent (AC220V/380V) |
| Undervoltage Trip Device | Undervoltage trip device of the same brand | Differences in mounting position and interface |
- Supplementary Selection Instructions
- Breaking capacity upgrade: If the system short-circuit current is greater than 50kA, models with H-grade (70ال) breaking capacity can be selected (على سبيل المثال, Schneider NSX800H, ABB T6H).
- Intelligent upgrade: Models with communication functions can be considered (على سبيل المثال, Schneider NSX800H with Micrologic 5.0) to realize remote monitoring.
- Cost optimization: Domestic brands (Changshu CM3, DELIXI CDM3) are about 60-70% of the price of international brands with equivalent performance.