Dongfa Intelligent manufactures the GNM1E series Electronic Molded Case Circuit Breaker MCCB for low-voltage power distribution and motor protection applications. The series includes 125A, 250A, 400A, 630A, and 800A frame sizes and uses an electronic trip unit with adjustable protection settings. The setting current can be configured within 0.4-1.0In, while the trip unit provides long-time, short-time, and instantaneous protection functions.
The GNM1E series is available with 3-pole or 4-pole configurations and L/M/H breaking capacity levels. Selection should be based on frame current, setting current, prospective short-circuit current, pole configuration, protection mode, and coordination requirements.
The GNM1E series uses an electronic trip unit to detect circuit current and process protection signals. Compared with a conventional thermal-magnetic protection mechanism, the electronic configuration allows specified protection parameters to be adjusted according to the application. The adjustable parameters include setting current, long-time delay, short-time delay, and instantaneous protection settings. This configuration allows the breaker to be selected according to different circuit and coordination requirements.
The setting current IR can be adjusted within 0.4-1.0 times the rated frame current, depending on the selected configuration. For example, a 250A frame can be configured with a setting current from 100A to 250A.
The frame current and setting current should be considered separately during product selection. The frame defines the basic current capacity of the breaker, while the setting current determines the applicable protection level for the circuit.
The short-time delay and instantaneous settings should be selected together with the characteristics of downstream breakers and the short-circuit conditions of the installation.
Distribution protection is intended for general low-voltage distribution circuits. When selecting the configuration, the frame current, setting current, breaking capacity, poles, and coordination requirements should be reviewed together.
The long-time protection setting should also be matched with the load and conductor requirements of the protected circuit.
Motor circuits can have different starting current characteristics from ordinary distribution loads. The GNM1E trip unit therefore provides a motor protection mode with a corresponding operating characteristic.
In the motor protection mode, the specified operating time at 1.5Ir1 varies according to the selected configuration. The protection setting should be confirmed according to the motor starting characteristics and system requirements.
Where several circuit breakers are installed at different levels of a distribution system, protection settings can be selected to coordinate their operating characteristics.
Short-time delay is one of the parameters considered for time coordination between upstream and downstream breakers. The actual coordination result depends on the complete protection system, including breaker characteristics, fault current, cable configuration, and selected settings.
The Electronic Molded Case Circuit Breaker MCCB includes utilization Category A and Category B configurations. The category is related to the short-time withstand requirements of the breaker and the intended coordination arrangement.
The 125A and 250A frame configurations are Category A. These configurations do not have a specified Icw value in the supplied technical data and can be considered for general distribution applications where the corresponding short-time withstand requirement does not apply.
The 400A, 630A, and 800A frame configurations are Category B and have specified short-time withstand current Icw values of 5kA, 8kA, and 10kA respectively.
Category B configurations can be considered for distribution systems where short-time withstand and selective coordination requirements need to be evaluated.
| Parameter | GNM1E-125 | GNM1E-250 | GNM1E-400 | GNM1E-630 | GNM1E-800 |
| Frame Current Inm | 125A | 250A | 400A | 630A | 800A |
| Poles | 3P / 4P | 3P / 4P | 3P / 4P | 3P / 4P | 3P / 4P |
| Setting Current IR | 0.4-1.0In | 0.4-1.0In | 0.4-1.0In | 0.4-1.0In | 0.4-1.0In |
| Rated Insulation Voltage Ui | 1000V | 1000V | 1000V | 1000V | 1000V |
| Rated Operating Voltage Ue | 400V / 690V | 400V / 690V | 400V / 690V | 400V / 690V | 400V / 690V |
| Rated Impulse Withstand Voltage Uimp | 8kV | 8kV | 8kV | 8kV | 8kV |
| Utilization Category | A | A | B | B | B |
| Arc Distance | 50mm | 50mm | 100mm | 100mm | 100mm |
| Electrical Life | 10,000 operations | 10,000 operations | 10,000 operations | 8,000 operations | 8,000 operations |
| Model | Breaking Capacity Level | Icu (kA) | Ics (kA) | Icw (kA) |
| GNM1E-125 | L / M / H | 35 / 50 / 80 | 22 / 35 / 50 | — |
| GNM1E-250 | L / M / H | 35 / 50 / 85 | 22 / 35 / 50 | — |
| GNM1E-400 | L / M / H | 35 / 85 / 100 | 22 / 55 / 65 | 5 |
| GNM1E-630 | L / M / H | 25 / 85 / 100 | 18 / 55 / 65 | 8 |
| GNM1E-800 | L / M / H | 35 / 85 / 100 | 22 / 55 / 65 | 10 |
| Frame Current | Maintenance-Free Mechanical Life | Mechanical Life with Maintenance |
| 125A | 20,000 operations | 40,000 operations |
| 250A | 20,000 operations | 40,000 operations |
| 400A | 20,000 operations | 20,000 operations |
| 630A | 10,000 operations | 20,000 operations |
| 800A | 10,000 operations | 20,000 operations |
The frame current should first be selected according to the required current capacity. The setting current is then configured according to the actual load and protection requirements.
For the GNM1E series, available frame sizes are 125A, 250A, 400A, 630A, and 800A. The setting current is adjustable within 0.4-1.0In according to the selected configuration.
The required breaking capacity should be selected according to the prospective short-circuit current at the installation point. The GNM1E series provides L/M/H breaking capacity levels, with the corresponding Icu and Ics values listed in the technical table.
3-pole and 4-pole configurations are available. The appropriate pole number should be selected according to the circuit arrangement and system design.
Select the distribution or motor protection mode according to the protected load. Utilization Category A or B should then be considered based on the short-time withstand and coordination requirements of the distribution system.
Dongfa Intelligent has established management systems certified to ISO 9001, ISO 14001, and ISO 45001, covering quality management, environmental management, and occupational health and safety. These certifications support standardized management across product development, manufacturing, and daily production operations.
Key high-voltage electrical products have undergone type testing by the National High-Voltage Electrical Apparatus Quality Supervision and Inspection Center. Product testing covers applicable electrical and mechanical performance requirements, with relevant test reports and technical documents available according to the product and project requirements.
Founded in 2012, Dongfa Intelligent operates a production facility of more than 2,000m² with 2 production lines and a team of 17 employees, including 4 R&D and technical personnel. The company supports OEM/ODM manufacturing based on customer drawings, technical specifications, and confirmed application requirements.
Dongfa Intelligent's management systems are certified to ISO 9001, ISO 14001, and ISO 45001. The company provides both high-voltage and low-voltage electrical products, allowing technical requirements for different voltage levels to be coordinated through the same manufacturing organization.
A thermal-magnetic MCCB uses thermal and electromagnetic protection mechanisms, while an electronic MCCB uses an electronic trip unit to process current signals. The GNM1E configuration provides adjustable setting current and specified adjustable protection parameters for long-time, short-time, and instantaneous protection.
It means that the setting current IR can be configured from 0.4 to 1.0 times the rated frame current, according to the selected configuration. For example, a 250A frame has a setting current range of 100A to 250A.
The long-time protection setting should be selected according to the protected circuit, load characteristics, and coordination requirements. At 2Ir1, the specified long-time delay range is 12-80s for 125A and 250A frames and 12-150s for 400A, 630A, and 800A frames.
Category A configurations do not have a specified Icw value in the supplied technical data. Category B configurations have a specified short-time withstand current Icw. In the Electronic Molded Case Circuit Breaker MCCB, 125A and 250A frames are Category A, while 400A, 630A, and 800A frames are Category B.
Standard products support a minimum order quantity of 1 unit. Standard products generally require 7-15 working days, while customized products generally require 15-30 working days. Final lead time should be confirmed according to the selected configuration and production schedule.
Please provide the frame current, setting current requirement, breaking capacity, pole configuration, protection mode, utilization category, and quantity. For replacement projects, the original breaker model and mounting dimensions are also recommended.
For replacement projects, provide the original breaker model and mounting dimensions together with the electrical requirements. This information allows the configuration and physical compatibility to be reviewed before production.
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