1. Safety Information
Please read all safety information carefully before installation and operation. Failure to follow these instructions may result in electric shock, fire, or serious injury.
General Safety Warnings:
- Warning: To avoid danger of suffocation, keep any packaging bags away from babies and children. Do not use this bag in cribs, beds, carriages, or playpens. This bag is not a toy.
- Installation and operation must be performed by a qualified electrical professional.
- Ensure the device is disconnected from power before any installation, maintenance, or inspection.
- Do not place the device near flammable materials.
- Ensure adequate ventilation during operation to prevent overheating.
- Disconnect from power and store properly when not in use for extended periods.
This product is marked with the CE symbol, indicating compliance with European safety standards.
Figure 1: Front view of the TOMZN TOB1Z-125 DC Miniature Circuit Breaker.
2. Product Overview
The TOMZN TOB1Z-125 DC Molded Case Circuit Breaker (MCB) is designed for DC rated voltage up to 1000V and rated current up to 125A. It provides essential overload and short circuit protection for DC lines and is suitable for infrequent operation. This circuit breaker is commonly used in DC applications such as communications systems and photovoltaic (PV) systems, ensuring compliance with IEC60947-2 standards.
Function Overview:
Once the specified current is reached, the device automatically trips (breaks the circuit), thereby protecting the connected electrical circuit from damage due to overcurrent or short circuit conditions.
Product Components:
Figure 2: Product appearance display with labeled components.
- Terminals: Connection points for electrical wiring.
- PC Flame Retardant Casing: Provides protection and safety.
- Brand (TOMZN): Manufacturer's identification.
- Model Number (TOB1Z-125): Specific product identifier.
- Breaking Capacity (10kA): Maximum fault current the breaker can safely interrupt.
- Rated Current (C80, C100, C125): The maximum continuous current the breaker is designed to carry.
- Wiring Diagram: Visual guide for correct electrical connections.
- Operating Handle: Used to manually switch the breaker ON or OFF, and indicates trip status.
- Fastening Screws: For securing wiring to the terminals.
3. Specifications
Electrical Data:
| Attribute | Value |
|---|---|
| Rated Current (In) | 80A, 100A, 125A |
| Poles | 2P |
| Rated Voltage (Ue) | 2P: 600V DC |
| Insulation Voltage (Ui) | 1000V |
| Rated Breaking Capacity (Ics=Icu) | 10kA (10000A) |
| Rated Impulse Withstand Voltage (Uimp) | 6KV |
| Thermo-magnetic Release Characteristic | B: 6In ± 20%, C: 12In ± 20% |
| Mechanical Life | 20000 operations |
Installation Data:
| Attribute | Value |
|---|---|
| Contact Position Indicator | Yes |
| Protection Degree | IP20 |
| Reference Temperature for Thermal Element Setting | 30°C |
| Ambient Temperature (daily average ≤ 35°C) | -5°C to +40°C |
| Storage Temperature | -25°C to +70°C |
| Terminal Connection Type | Cable / U-type busbar / Pin-type busbar |
| Terminal Size (Top/Bottom for Cable) | 25mm² 18-3 |
| Tightening Torque | 3.0N·m |
| Mounting | On DIN rail FN 60715 (35mm) by means of fast clip device |
| Connection | Top and bottom |
Figure 3: Available current ratings: 80A, 100A, and 125A.
4. Installation
Proper installation is crucial for the safe and effective operation of the circuit breaker. It is highly recommended that installation be performed by a qualified electrical professional.
Installation Steps:
- After receiving the product, ensure an electrical professional performs the installation and initial setup.
- Connect the equipment in accordance with the provided wiring diagram specifications.
- Adjust any necessary equipment parameters according to the system requirements and these instructions.
Mounting:
The TOB1Z-125 is designed for mounting on a 35mm DIN rail (FN 60715) using its fast clip device. Ensure the DIN rail is securely installed before mounting the circuit breaker.
Figure 4: Circuit breaker mounted on a DIN rail.
Wiring Diagrams (DC Applications):
The following diagrams illustrate typical wiring configurations for DC applications. Always refer to the specific diagram printed on your device and consult local electrical codes.
-
2P Wiring Diagram:
The 2-pole configuration shows two independent circuits. For a 2P breaker, the positive (+) input connects to terminal 1, and the negative (-) input connects to terminal 3. The corresponding outputs are from terminal 2 and terminal 4 respectively. The internal diagram shows the current path from 1 to 2 and 3 to 4, with the operating handle controlling both poles simultaneously.
Figure 5: Example installation in a PV system with a battery.
Overall and Mounting Dimensions:
The dimensions for the 2P model are approximately 54mm width, 87mm height, and 74mm depth (including terminals). The DIN rail mounting clip is located at the rear. Always verify dimensions against the physical product for precise installation planning.
Figure 6: Bottom view of the circuit breaker showing terminal connections.
5. Operation
The TOMZN TOB1Z-125 DC MCB operates as a protective device for electrical circuits. Its primary function is to automatically interrupt the flow of current when an overcurrent or short circuit condition is detected.
Operating the Handle:
- ON Position: Push the operating handle upwards to close the circuit and allow current to flow.
- OFF Position: Push the operating handle downwards to open the circuit and stop current flow.
- Tripped Position: If an overcurrent or short circuit occurs, the handle will automatically move to an intermediate or OFF position, indicating that the breaker has tripped to protect the circuit. Before resetting, identify and resolve the fault.
6. Maintenance
The TOB1Z-125 DC MCB is designed for reliable operation with minimal maintenance. However, periodic checks and adherence to precautions can extend its lifespan and ensure safety.
General Maintenance and Precautions:
- Environmental Conditions: Ensure the device is not exposed to excessive moisture, dust, or corrosive environments. Operate within the specified ambient temperature range (-5°C to +40°C).
- Ventilation: Always ensure adequate air circulation around the circuit breaker to dissipate heat, especially during continuous operation.
- Flammable Materials: Keep the circuit breaker away from any flammable liquids, gases, or materials.
- Storage: When not in use for extended periods, disconnect the device from power and store it in a dry, cool place within the specified storage temperature range (-25°C to +70°C).
- Inspection: Periodically inspect the terminals for tightness and ensure there are no signs of overheating, discoloration, or physical damage to the casing.
7. Troubleshooting
If the circuit breaker trips frequently or fails to operate as expected, consider the following general troubleshooting steps:
- Frequent Tripping: This often indicates an overload or a short circuit in the protected circuit. Disconnect loads one by one to identify the faulty appliance or wiring issue. Do not repeatedly reset a tripping breaker without investigating the cause.
- Failure to Reset: If the breaker does not reset after tripping, ensure the fault has been cleared. If it still won't reset, the breaker itself might be damaged and require replacement.
- No Power: Check all connections for tightness and ensure the breaker is in the ON position. Verify the power source is active.
- Physical Damage: Inspect the breaker for any visible signs of damage, such as cracks, burns, or loose terminals. A damaged breaker must be replaced immediately.
For complex issues or if you are unsure about any troubleshooting steps, always consult a qualified electrician or the product manufacturer.
8. User Tips
Based on user experiences, here are some helpful tips for using your TOMZN DC MCB:
- Check Packaging Upon Arrival: While the product itself is robust, sometimes packaging can get dented during transit. Always inspect the circuit breaker for any physical damage before installation.
- DIN Rail Compatibility: This breaker is designed for DIN rail mounting. If you don't already have one, you may need to acquire a 35mm DIN rail for installation.
- Professional Installation: Many users emphasize the importance of professional installation, especially for PV systems, to ensure correct wiring and safety.
9. Applicable Regulations and Standards
This TOMZN DC Miniature Circuit Breaker complies with the following regulations and harmonized standards:
- Low Voltage Directive (LVD) 2014/35/EU
- EN IEC 60947-1:2021
- EN IEC 60947-3:2021
Certifications:
- CE
- ISO9001
- IQNET
- CCC
Figure 7: TOMZN brand sticker with certification logos.
10. Warranty and Support
For specific warranty terms and conditions, please refer to the documentation provided at the time of purchase or contact the seller directly. If you require technical support or have questions regarding installation or operation, please reach out to the TOMZN Official Store or a certified electrical professional.
A detailed user manual in PDF format is available for further reference: