| Parameter | Specification |
|---|---|
| Product Series | SUNTREE SM8 |
| Product Type | AC Molded Case Circuit Breaker (AC MCCB) |
| Frame Ratings | 63A / 125A / 250A / 400A / 630A / 800A |
| Rated Current (In) | 10A–800A, depending on model |
| Pole Configuration | 2P / 3P / 4P |
| Rated Insulation Voltage (Ui) | 800V / 1000V AC |
| Rated Operating Voltage (Ue) | 400V / 415V / 690V AC |
| Rated Impulse Withstand Voltage (Uimp) | 8kV |
| Ultimate Short-Circuit Breaking Capacity (Icu) | Up to 100kA, depending on model and capacity class |
| Service Short-Circuit Breaking Capacity (Ics) | Up to 75kA, depending on model and capacity class |
| Arc Extinguishing System | Labyrinth Arc Extinguisher |
| Moving Contacts | Built-in Double-Row Moving Contacts |
| Base Material | DMC V0 Flame-Retardant Material |
| Accessories | Excitation / Auxiliary / Alarm |
| Certifications | TUV / CE / CB |
The exact voltage, breaking capacity and rated current depend on the selected SM8 frame and capacity class.
The SUNTREE SM8 series includes six main frame sizes:
| Model | Frame Rating | Available Rated Current | Poles |
| SM8-63 | 63A | 10A / 16A / 20A / 25A / 32A / 40A / 50A / 63A | 2P / 3P / 4P |
| SM8-125 | 125A | 16A / 20A / 25A / 32A / 40A / 50A / 63A / 80A / 100A / 125A | 2P / 3P / 4P |
| SM8-250 | 250A | 100A / 125A / 160A / 180A / 200A / 225A / 250A | 2P / 3P / 4P |
| SM8-400 | 400A | 225A / 250A / 315A / 350A / 400A | 3P / 4P |
| SM8-630 | 630A | 400A / 500A / 630A | 3P / 4P |
| SM8-800 | 800A | 630A / 700A / 800A | 3P / 4P |
These model and current combinations are listed in the official SUNTREE electrical technical reference.
| Parameter | Specification |
| Rated Insulation Voltage (Ui) | 800V AC for SM8-63 / 1000V AC for larger frames |
| Rated Operating Voltage (Ue) | 400V / 415V / 690V AC |
| Rated Impulse Withstand Voltage (Uimp) | 8kV |
| Rated Current | 10A–800A |
| Pole Configuration | 2P / 3P / 4P |
| Breaking Capacity | Up to 100kA at applicable ratings |
| Service Breaking Capacity | Up to 75kA at applicable ratings |
The SM8 series provides different breaking-capacity classes, including L, M and H, with the available capacity depending on the model and operating voltage.
The breaking capacity of the SM8 varies according to frame size, capacity class and operating voltage.
| Model / Class | Maximum Icu | Maximum Ics |
| SM8-63 | Up to 35kA | Up to 27kA |
| SM8-125 | Up to 50kA | Up to 42kA |
| SM8-250 | Up to 85kA | Up to 63kA |
| SM8-400 | Up to 100kA | Up to 75kA |
| SM8-630 | Up to 100kA | Up to 75kA |
| SM8-800 | Up to 100kA | Up to 75kA |
At 690V AC, the applicable breaking capacity is lower for the larger frames, with the technical reference listing values up to 30kA Icu and 20kA Ics depending on model.
| Protection Function | Specification |
| Overload Protection | Yes |
| Short-Circuit Protection | Yes |
| Circuit Isolation | Yes |
| Arc Extinguishing | Labyrinth Arc Extinguisher |
| Contact System | Double-Row Moving Contacts |
| Short-Circuit Interruption | High-Speed Arc Extinguishing |
| Accessory Protection Functions | Excitation / Auxiliary / Alarm |
The labyrinth arc-extinguishing structure is designed to prevent arc propagation during current surges, while the double-row moving contacts increase arc voltage to improve circuit interruption performance.
One of the key features of the SM8 series is its labyrinth arc-extinguishing system.
The arc-extinguishing chamber is designed to control and suppress the electrical arc generated when the MCCB interrupts a fault current. This helps prevent the arc from spreading and supports safer interruption during overload and short-circuit events.
The SM8 also uses built-in double-row moving contacts, which are designed to increase the arc voltage and improve the interruption characteristics of the breaker.
The SM8 series supports several optional accessories that can expand its protection, control and signaling capabilities.
| Accessory | Function |
| Excitation Accessory | Additional control/protection function |
| Auxiliary Contact | Remote indication of breaker status |
| Alarm Contact | Fault/trip indication |
SUNTREE specifically highlights the easy installation of accessories for realizing multiple protection and control functions.
The SM8 series is designed as a molded-case circuit breaker with a flame-retardant insulating base.
| Parameter | Specification |
| Construction | Molded Case |
| Base Material | DMC V0 Flame-Retardant Material |
| Contact System | Double-Row Moving Contacts |
| Arc Chamber | Labyrinth Type |
| Pole Options | 2P / 3P / 4P |
The DMC V0 flame-retardant base provides an insulating enclosure designed for electrical safety and resistance to flame propagation.
The operational life of the SM8 depends on the frame size.
| Frame Group | Electrical Operations (On Power) | Mechanical Operations (No Power) |
| SM8-63 / SM8-125 | Up to 3,000 | Up to 15,000 |
| SM8-250 / SM8-400 | Up to 2,000 | Up to 10,000 |
| SM8-630 / SM8-800 | Up to 1,000 | Up to 7,000 |
The exact operational performance depends on the selected frame and operating conditions.
The SUNTREE SM8 is an AC molded case circuit breaker (MCCB) designed for overload and short-circuit protection in low-voltage AC electrical distribution systems.
The SM8 series covers rated currents from 10A to 800A, depending on the selected model. Frame sizes include 63A, 125A, 250A, 400A, 630A and 800A.
The SM8 series supports AC operating voltages including 400V, 415V and 690V, depending on the specific model and configuration. The rated insulation voltage is 800V or 1000V AC, depending on frame size.
The SM8 series is available in 2P, 3P and 4P configurations. The SM8-400, SM8-630 and SM8-800 models are listed with 3P and 4P options.
The maximum listed ultimate short-circuit breaking capacity reaches 100kA, depending on the model, capacity class and voltage.
The L, M and H classifications represent different short-circuit breaking-capacity levels. The H class provides the highest breaking capacity among these options, but the actual value depends on the selected SM8 frame and operating voltage.
Yes. The SM8 is designed to provide overload and short-circuit protection for AC electrical distribution systems.
Yes. The SM8 uses a labyrinth arc extinguisher designed to prevent the spread of arcs during current surges. It also incorporates double-row moving contacts to increase arc voltage and improve interruption performance.
2 reviews for SUNTREE SM8 Moulded Case Circuit Breaker
Tahlia –
What current and voltage options are available for the SM8 series?
Kellie –
The moulded-case design looks robust and suitable for installations that need reliable circuit protection.