Chint Miniature Circuit Breaker, MCB, AC Breaker, 1 or 3 Poles, 20/25/32/63A
$8.82 – $20.74
MOQ: 1 carton Packing: 180 pcs/carton for 1 pole models 60 pcs/carton for 3-pole models
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Description
The Chint CT-NB1-63 is a high-quality miniature circuit breaker (MCB) that protects electrical circuits from overloads and short circuits.
In simple terms, a circuit breaker is an automatic switch that opens the circuit when current exceeds a safe level. The CT-NB1-63 will automatically trip and disconnect power under fault conditions, preventing damage, overheating, or fire. The NXB-63 series is suitable for residential, commercial, and industrial distribution panels.
Available in 1-pole or 3-pole versions with current ratings from 20 A up to 63 A, this Chint circuit breaker covers a broad range of applications. Each breaker features a positive isolation ensures the contacts are visibly open when tripped on the handle and a trip-free mechanism (it cannot be held ON during a fault), ensuring clear status and reliable operation.
Chint – NXB-63 Miniature Circuit Breaker
The CT-NB1-63 (also known as NB1-63, or NXB-63 in some catalogs) is an AC DIN-rail MCB series. It is rated for circuits up to 63 A and supports both single-phase and three-phase AC. Specifically, 1P/1P+N versions cover 220/230/240 VAC, while 3P/3P+N or 4P versions handle 380/400/415 VAC.
The breakers operate at 50/60 Hz with a thermal-magnetic trip unit: a bimetal strip trips under sustained overload, and a magnetic coil trips instantly under a short circuit. The CT-NB1-63 comes with selectable trip characteristics (Type B, C or D) to suit different load types. For example, a Type C curve (5–10×In) is ideal for general lighting and socket circuits, while a Type D (10–14×In) is used where heavy inrush currents occur (motors or transformers).
This breaker complies with IEC/EN 60898-1 (household use) and IEC/EN 60947-2 (industrial use) standards. It has a short-circuit breaking capacity of up to 6000 A (Icn) at 230/400 VAC, ensuring it can interrupt high fault currents. Built for durability, it offers a mechanical life of 20,000 operations and a rated insulation voltage of 500 V (impulse withstand 4 kV).
Overall, the CT-NB1-63 is a compact, versatile breaker suitable for solar systems, industrial panels, and home use.
Key Features of Chint circuit breaker NXB-63
- Standards: Complies with IEC/EN 60898-1 and IEC/EN 60947-2 (equivalent to AS/NZS 60898 in Australia).
- Poles: Available in 1P, 1P+N, 2P, 3P, 3P+N, and 4P configurations.
- Amperage: Factory-set for 20A, 25A, 32A, 40A, 50A, or 63A.
- Voltage Rating: Up to 240 VAC on 1P units; up to 415 VAC on 3P/4P units.
- Trip Curves: Thermal-magnetic release with selectable Type B, C, or D tripping curves.
- Breaking Capacity: Up to 6000 A (Icn) at 230/400 VAC (enough for typical fault levels).
- Durability: 20,000 mechanical cycles, 10,000 electrical cycles.
- Insulation: Rated insulation voltage Ui 500 V; impulse withstand 4 kV.
- Mounting: Snap-on 35 mm DIN-rail (EN 60715) installation.
- Safety: Color-coded ON/OFF indicator and trip-free design for reliable operation.
- Isolation: Provides visible isolation when tripped or switched off.
Main Benefits
Solar Contractors: Ideal for solar PV installations. The CT-NB1-63 can protect inverter outputs and AC branch circuits. Its high breaking capacity and compliance make it suitable for grid-tie inverters or off-grid systems. Solar installers can use the 3P models for three-phase inverters or combiner boxes, and 1P models for single-phase circuits.
Wholesalers & Distributors: A widely-used Chint circuit breaker, the CT-NB1-63 is a staple in solar and electrical supply. Electrical wholesalers benefit from stocking a trusted, IEC-certified MCB that fits Aussie standards. Solar Rains provides wholesale quantities and trade terms, making it easy to supply this breaker to installers and retailers.
Homeowners & Electricians: For home or small business use, this breaker offers everyday protection. For example, a 20 A breaker might safeguard a living-room circuit, a 32 A breaker could protect a kitchen circuit or air conditioner, and a 63 A breaker can serve as a sub-main switch. Its resettable design adds convenience over fuses. With clear ON/OFF indication and Australian voltage ratings, it keeps domestic wiring safe and easy to manage.
Application Scenarios
- Single-Phase Loads (1P): Use a 1-pole CT-NB1-63 for standard 230 VAC circuits (e.g. lighting, outlets). 20–32 A 1P breakers are typical for home circuits.
- Three-Phase Loads (3P): Use a 3-pole breaker for three-phase 400 VAC systems (e.g. motors, large HVAC). For instance, a 3P 32 A breaker might protect a workshop machine, while a 3P 63 A breaker could protect a factory feeder.
- Sizing by Load: Pick the breaker rating to exceed the normal running current. A 20 A breaker suits lighter loads; a 32 A breaker suits heavier appliances or sub-circuits; a 63 A breaker suits main feeds or heavy industrial equipment. Always allow headroom for startup currents (e.g. motors).
Residential Use: In Australian homes, CT-NB1-63 breakers match the 230/415 VAC supply. For example, a 32 A breaker can protect an electric hot water system or oven circuit, while 20 A breakers protect general outlets. - Solar & Commercial: On the AC side of a solar inverter, use an appropriately-rated CT-NB1-63 as the system disconnect or array protection. In offices or factories, use 3P versions for multi-phase distribution or machinery.
Installation Guidance
The Chint CT-NB1-63 miniature circuit breaker is designed for fast, safe installation in residential, commercial, and industrial electrical systems. It supports DIN-rail mounting and accommodates a wide range of circuit configurations.
To ensure optimal performance, the breaker must be mounted on a standard TH35-7.5 DIN rail, with the terminals securely fastened using a torque of 2.0 N·m. Use copper conductors only for wiring, and select wire sizes that match the rated current:
- 10–16 A models: 1.5–2.5 mm² wires
- 20–25 A models: 4 mm² wires
- 32 A models: 6 mm² wires
- 40–50 A models: 10 mm² wires
- 63 A models: 16 mm² wires
Before installation, ensure that the incoming circuit is de-energised. The breaker should be snapped onto the rail and aligned vertically to facilitate a clean fit and proper heat dissipation. The CT-NB1-63 includes a trip-free mechanism, meaning the switch cannot be held in the ON position during fault conditions. This feature guarantees reliable disconnection and visible ON/OFF status at all times.
The breaker supports both single-phase and three-phase applications. For 1P or 1P+N models, install on 230–240 VAC circuits; for 3P or 3P+N, use on 400–415 VAC three-phase systems. Always match the trip curve type (B, C, or D) to the characteristics of the connected load.
Environmental & Safety Conditions
The CT-NB1-63 is engineered for indoor environments with controlled conditions and is not suitable for outdoor use or wet locations. Its IP20-rated enclosure offers basic protection against finger contact but does not resist dust or water ingress. Therefore, it must be installed inside a distribution board or weatherproof enclosure when deployed near moisture.
Key environmental limits include:
- Operating altitude: ≤ 2000 m
- Ambient temperature: -5°C to +40°C (with derating above 30°C)
- Pollution degree: Class 2
- Installation category: Class II & III (per IEC standards)
The breaker is not recommended for direct switching of large inductive loads, such as heavy motors, HVAC compressors, or heaters, unless proper circuit protection is provided upstream. High inrush current loads may require a Type D curve breaker or additional protective components.
During installation, avoid corrosive environments (e.g. chemical fumes, salt-laden air), as these may degrade insulation and terminal contact performance. All wiring must conform to local electrical codes, and installation should only be performed by a licensed electrician.
By following these environmental and installation best practices, the CT-NB1-63 will deliver dependable performance, protect against overloads and short circuits, and contribute to the long-term safety and efficiency of your electrical system.
Caveat: The product description and datasheet on this page may not be the most updated version. Please refer to the user manual coming with products if there are conflicts.
Chint Global
CHINT is a global leader in smart energy and low-voltage electrical solutions. Founded in 1984, the company has over 40 years of experience in manufacturing low-voltage appliances and photovoltaic products.
With business in 140+ countries and a 2024 revenue of about USD 25 billion, Chint is renowned for quality and innovation. This strong pedigree means Chint’s breakers—like the CT-NB1-63—are built to high standards and trusted worldwide.
In Australia, Chint circuit breakers are popular for solar and general electrical projects thanks to this reputation.
A circuit breaker is an automatic safety switch that protects an electrical circuit. It “breaks” the circuit by opening its contacts whenever current exceeds a safe level (due to overload or short-circuit). Essentially, it prevents damage and fire by cutting power in unsafe conditions. The CT-NB1-63 trips off and isolates the circuit under fault conditions, and can be reset once the problem is fixed. This circuit breaker definition means it acts like a reusable fuse, allowing normal operation but stopping dangerous current.
The CT-NB1-63 uses a thermal-magnetic trip unit. Under a prolonged overload, an internal bimetal strip heats up and bends, slowly tripping the breaker. Under a sudden short-circuit, a magnetic coil instantly trips the breaker. This opens the breaker contacts and cuts power. The CT-NB1-63 offers Type B, C, or D trip curves, so it can handle different load profiles. For example, Type C is common for lighting circuits, while Type D handles high inrush (motors/transformers). In all cases, when the current exceeds the chosen threshold, the breaker automatically trips to protect the circuit.
Use a 1P (single-pole) breaker for single-phase 230 VAC circuits, which is typical in houses and small commercial panels. Use a 3P (three-pole) breaker for 3-phase systems at 380–415 VAC, common in industrial or larger commercial settings. For example, a house light circuit would use 1P, while a three-phase motor or distribution sub-panel would use 3P. The CT-NB1-63 series supports 1P, 1P+N, 2P, 3P, 3P+N, and 4P, so you can match the exact circuit configuration.
Select the breaker amperage to match the normal load current. A 20 A breaker (20 amp) is for lighter loads like lighting or small outlets. A 32 A breaker (32 amp) is for heavier circuits (ovens, air conditioners, workshop tools). A 63 A breaker is for very heavy loads or main feeds. For example, use a 32 A circuit breaker to protect a kitchen circuit with appliances, and a 20 A breaker for a living-room circuit. The breaker’s rating should be slightly above the expected maximum current. Always adhere to wiring regulations and consult an electrician for precise sizing.
Yes. The Chint circuit breaker CT-NB1-63 meets international safety standards IEC/EN 60898-1 and IEC/EN 60947-2, which align with Australian/New Zealand requirements (AS/NZS 60898). It has CE and other global certifications. It is designed for Australia’s 230/400VAC grid and 50 Hz frequency. For safety, it must be installed by a qualified electrician according to local codes. When installed correctly, it provides reliable protection and peace of mind.
| Dimensions and Weights | |
|---|---|
| SKU | CT-NB1-63 1P C32 |
| Weight | 24 kg |
| Dimensions | 44 x 26 x 24 cm |
| Dimensions and Weights | |
|---|---|
| SKU | CT-NB1-63 1P C63 |
| Weight | 24 kg |
| Dimensions | 44 x 26 x 24 cm |
| Dimensions and Weights | |
|---|---|
| SKU | CT-NB1-63 3P C20 |
| Weight | 24 kg |
| Dimensions | 44 x 26 x 24 cm |
| Dimensions and Weights | |
|---|---|
| SKU | CT-NB1-63 3P C25 |
| Weight | 24 kg |
| Dimensions | 44 x 26 x 24 cm |
| Dimensions and Weights | |
|---|---|
| SKU | CT-NB1-63 3P C32 |
| Weight | 24 kg |
| Dimensions | 44 x 26 x 24 cm |
| Dimensions and Weights | |
|---|---|
| SKU | CT-NB1-63 3P C63 |
| Weight | 24 kg |
| Dimensions | 44 x 26 x 24 cm |
| Dimensions and Weights | |
|---|---|
| SKU | CT-NB1-63 1P C20 |
| Weight | 24 kg |
| Dimensions | 44 x 26 x 24 cm |
| Dimensions and Weights | |
|---|---|
| SKU | CT-NB1-63 1P C25 |
| Weight | 24 kg |
| Dimensions | 44 x 26 x 24 cm |
| Download Area | |
|---|---|
| NXB-63 Miniature circuit breaker - product description | Download |
| Certificate of Conformity | Download |
| CHINT Warranty Policy 2024 | Download |
| Rated current | 20A | ||
| Rated voltage | 220V~/230V~/240V ~ (1P, 1P+N，2P) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 1P | ||
| Mechanical life | 20000 cycles | ||
| Electrical life | 10000 cycles | ||
| Rated short-circuit breaking capacity(Icn) | 6000A,10000A(2P, 220V/230V/240V) | ||
| Short-circuit breaking capacity (Ics) | 6000A, 7500A(2P, 220V/230V/240V) | ||
| Rated insulation voltage Ui | 500V | ||
| Rated impulse withstand voltage (Uimp) | 4kV | ||
| Maximum power consumption per pole (W) | 4.5 W |
| Rated current | 20A | ||
| Rated voltage | 220V~/230V~/240V ~ (1P, 1P+N，2P) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 1P |
| Rated current | 25A | ||
| Rated voltage | 220V~/230V~/240V ~ (1P, 1P+N，2P) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 1P | ||
| Mechanical life | 20000 cycles | ||
| Electrical life | 10000 cycles | ||
| Rated short-circuit breaking capacity(Icn) | 6000A,10000A(2P, 220V/230V/240V) | ||
| Short-circuit breaking capacity (Ics) | 6000A, 7500A(2P, 220V/230V/240V) | ||
| Rated insulation voltage Ui | 500V | ||
| Rated impulse withstand voltage (Uimp) | 4kV | ||
| Maximum power consumption per pole (W) | 4.5 W |
| Rated current | 25A | ||
| Rated voltage | 220V~/230V~/240V ~ (1P, 1P+N，2P) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 1P |
| Rated current | 32A | ||
| Rated voltage | 220V~/230V~/240V ~ (1P, 1P+N，2P) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 1P | ||
| Mechanical life | 20000 cycles | ||
| Electrical life | 10000 cycles | ||
| Rated short-circuit breaking capacity(Icn) | 6000A,10000A(2P, 220V/230V/240V) | ||
| Short-circuit breaking capacity (Ics) | 6000A, 7500A(2P, 220V/230V/240V) | ||
| Rated insulation voltage Ui | 500V | ||
| Rated impulse withstand voltage (Uimp) | 4kV | ||
| Maximum power consumption per pole (W) | 6 W |
| Rated current | 32A | ||
| Rated voltage | 220V~/230V~/240V ~ (1P, 1P+N，2P) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 1P |
| Rated current | 63A | ||
| Rated voltage | 220V~/230V~/240V ~ (1P, 1P+N，2P) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 1P | ||
| Mechanical life | 20000 cycles | ||
| Electrical life | 10000 cycles | ||
| Rated short-circuit breaking capacity(Icn) | 6000A,10000A(2P, 220V/230V/240V) | ||
| Short-circuit breaking capacity (Ics) | 6000A, 7500A(2P, 220V/230V/240V) | ||
| Rated insulation voltage Ui | 500V | ||
| Rated impulse withstand voltage (Uimp) | 13 kV |
| Rated current | 63A | ||
| Rated voltage | 220V~/230V~/240V ~ (1P, 1P+N，2P) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 1P |
| Rated current | 20A | ||
| Rated voltage | 380V~/400V~/415V ~ (2 ~ 4P, 3P+N) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 3P | ||
| Mechanical life | 20000 cycles | ||
| Electrical life | 10000 cycles | ||
| Rated short-circuit breaking capacity(Icn) | 6000A,10000A(2P, 220V/230V/240V) | ||
| Short-circuit breaking capacity (Ics) | 6000A, 7500A(2P, 220V/230V/240V) | ||
| Rated insulation voltage Ui | 500V | ||
| Rated impulse withstand voltage (Uimp) | 4kV | ||
| Maximum power consumption per pole (W) | 4.5 W |
| Rated current | 20A | ||
| Rated voltage | 380V~/400V~/415V ~ (2 ~ 4P, 3P+N) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 3P |
| Rated current | 25A | ||
| Rated voltage | 380V~/400V~/415V ~ (2 ~ 4P, 3P+N) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 3P | ||
| Mechanical life | 20000 cycles | ||
| Electrical life | 10000 cycles | ||
| Rated short-circuit breaking capacity(Icn) | 6000A,10000A(2P, 220V/230V/240V) | ||
| Short-circuit breaking capacity (Ics) | 6000A, 7500A(2P, 220V/230V/240V) | ||
| Rated insulation voltage Ui | 500V | ||
| Rated impulse withstand voltage (Uimp) | 4kV | ||
| Maximum power consumption per pole (W) | 4.5 W |
| Rated current | 25A | ||
| Rated voltage | 380V~/400V~/415V ~ (2 ~ 4P, 3P+N) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 3P |
| Rated current | 32A | ||
| Rated voltage | 380V~/400V~/415V ~ (2 ~ 4P, 3P+N) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 3P | ||
| Mechanical life | 20000 cycles | ||
| Electrical life | 10000 cycles | ||
| Rated short-circuit breaking capacity(Icn) | 6000A,10000A(2P, 220V/230V/240V) | ||
| Short-circuit breaking capacity (Ics) | 6000A, 7500A(2P, 220V/230V/240V) | ||
| Rated insulation voltage Ui | 500V | ||
| Rated impulse withstand voltage (Uimp) | 4kV | ||
| Maximum power consumption per pole (W) | 6 W |
| Rated current | 32A | ||
| Rated voltage | 380V~/400V~/415V ~ (2 ~ 4P, 3P+N) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 3P |
| Rated current | 63A | ||
| Rated voltage | 380V~/400V~/415V ~ (2 ~ 4P, 3P+N) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 3P | ||
| Mechanical life | 20000 cycles | ||
| Electrical life | 10000 cycles | ||
| Rated short-circuit breaking capacity(Icn) | 6000A,10000A(2P, 220V/230V/240V) | ||
| Short-circuit breaking capacity (Ics) | 6000A, 7500A(2P, 220V/230V/240V) | ||
| Rated insulation voltage Ui | 500V | ||
| Rated impulse withstand voltage (Uimp) | 4kV | ||
| Maximum power consumption per pole (W) | 13 W |
| Rated current | 63A | ||
| Rated voltage | 380V~/400V~/415V ~ (2 ~ 4P, 3P+N) | ||
| Frequency | 50/60Hz | ||
| Thermal magnetic release | B, C, D | ||
| Number of poles | 3P |
chan keung –
I like how this company runs, they always deliver promptly and help when needed. I’ve ordered multiple times, and it’s always been smooth
Raj Patel –
The breaker works fine, but the delivery was delayed a bit
Mark Reynolds –
Perfect for solar setups! Solar Rains delivered fast, and the product specs were spot-on
James O’Connor –
Great value for money! The Chint breaker is sturdy, and the ON/OFF indicator is super clear. Will order again for future projects!
Antoine –
The customer support chat is quick and helpful. A+
Jason Yeo –
Efficient, easy to install, and a great price for the value
Craig Mason –
Bought these to replace old ones, no issues. Very happy!