1. Product Overview
The TOMZN TOQ3-4P/125 is a 4-pole, 125A MCB type Dual Power Automatic Transfer Switch (ATS) designed for 3-phase, 4-wire electrical systems. It automatically switches between a normal power source (e.g., city power) and a reserve power source (e.g., generator or PV system) to ensure continuous power supply to critical loads. This device is suitable for AC 50/60Hz systems with a rated voltage of 230V/400V.
Figure 1: Front view of the TOMZN TOQ3-4P/125 ATS.
The ATS operates based on voltage relay theory and features high power contact load with sealed protection. It conforms to international standards IEC60947-6-1 and GB/T14048.11, ensuring reliability and safety.
2. Safety Information
- Installation and maintenance should only be performed by qualified electricians.
- Ensure all power sources are disconnected before installation or servicing to prevent electric shock.
- This 125A ATS model does not include overcurrent or short-circuit protection. Appropriate external circuit breakers or fuses must be installed upstream to provide necessary protection for the connected circuits and the ATS itself.
- Verify correct wiring and connections before applying power.
- Do not attempt to repair or modify the device. Contact qualified personnel for assistance.
3. Installation and Wiring
The TOQ3-4P/125 ATS is a terminal type automatic transfer device. It is designed for easy integration into existing electrical panels.
3.1 Mounting
The device features a bottom plate and mounting holes for secure installation. Ensure the mounting surface is stable and capable of supporting the device's weight.
Figure 2: Key components and mounting points of the ATS.
3.2 Wiring Connections
Connect the common power supply (e.g., utility grid) and the backup power supply (e.g., generator, inverter) to the designated terminals on the ATS. The load circuits should be connected to the output terminals of the ATS.
Important Wiring Notes:
- For 3-phase, 4-wire systems, ensure all three live phases (L1, L2, L3) and the neutral wire (N) are correctly connected for both common and backup power sources.
- The live wire must be connected to terminal '1' and the neutral wire to terminal 'N' on the respective input sides.
- Refer to the wiring diagram below for proper connection of common power, backup power, and load.
Figure 3: Main wiring diagram for the ATS, showing common power, backup power, and load connections.
The ATS also includes indicating terminals (1-6) for external signaling or control. Refer to the detailed terminal wiring diagram for these connections.
Figure 4: Detailed wiring for indicating terminals.
4. Operation
The ATS can operate in either automatic or manual mode, controlled by a selector switch on the front panel.
4.1 Automatic Mode
To enable automatic transfer, set the selector switch to the "Auto" position. In this mode, the ATS continuously monitors the normal power supply (specifically Phase A voltage). If the normal power fails (loss of voltage or phase), the switch will automatically transfer the load to the reserve power supply, provided the reserve power is available. When the normal power is restored, the ATS will automatically switch the load back to the normal power source.
- Power Interruption: Please note that there will be a brief power interruption (switch time < 4 seconds) during the transfer process between power sources.
- Generator Control: This ATS does not control the starting or stopping of a generator. The generator must be managed independently.
Figure 5: Working principle of the ATS, showing fast conversion.
4.2 Manual Mode
To operate the switch manually, set the selector switch to the "Manual" position. In this mode, you must manually switch the direction (between normal and reserve power) using the handle on the device. This mode is useful for testing or in situations where automatic transfer is not desired.
Figure 6: Selector switch for Automatic and Manual operation.
5. Maintenance
Regular inspection and maintenance can help ensure the longevity and reliable operation of your ATS.
- Visual Inspection: Periodically inspect the ATS for any signs of physical damage, loose connections, or overheating (discoloration).
- Cleaning: Keep the device clean and free from dust and debris. Use a dry, soft cloth for cleaning. Do not use liquids or abrasive cleaners.
- Connection Check: Ensure all terminal connections remain tight. Loose connections can lead to overheating and device failure.
- Functional Test: Periodically test the automatic transfer function by simulating a normal power outage (if safe and feasible) to ensure it switches correctly to the backup power.
Always disconnect power before performing any maintenance.
6. Troubleshooting
If you encounter issues with your ATS, consider the following basic troubleshooting steps. For complex problems, always consult a qualified electrician.
- No Transfer:
- Check if the ATS is in "Auto" mode.
- Verify that both normal and backup power sources are functioning correctly and providing the rated voltage.
- Inspect all wiring connections for looseness or damage.
- Partial Power:
- Ensure all phases (L1, L2, L3) and neutral (N) are correctly connected and receiving power from the active source.
- Check for tripped upstream circuit breakers or blown fuses on individual phases.
- Overheating:
- Immediately disconnect power.
- Check for loose connections or overloaded circuits. Remember, this ATS does not have built-in overcurrent protection.
If the problem persists, contact customer support or a certified electrician.
7. Specifications
Figure 7: Detailed product parameters and dimensions.
| Feature | Specification |
|---|---|
| Model Number | TOQ3-4P/125 |
| Brand Name | TOMZN |
| Rated Current (Ie) | 125A |
| Rated Voltage (Ue) | AC 230V/400V (3-phase, 4-wire system) |
| Rated Impulse Withstand Voltage (Uimp) | 4kV (Main circuit) |
| Frequency | 50/60Hz |
| Utilization Category | AC-33B |
| ATSE Class | CB |
| Rated Short-Circuit Making Capacity (Icm) | 7.65kA (Peak), 9.18KA (Peak) |
| Rated Short-Circuit Breaking Capacity (Icn) | 5kA (Effective value), 6KA (Effective value) |
| Tripping Current | 5-10In (Type C), 10-15In (Type D) |
| Electrical Appliances Class | CB |
| Standard | IEC60947-6-1, GB/T14048.11 |
| Dimensions (L x W x H) | 255mm x 125mm x 136mm (approx.) |
| Protect Feature | Sealed |
| Use | Dual power switch |
8. User Tips
- Professional Installation: Due to the electrical nature of this device, professional installation by a licensed electrician is highly recommended to ensure safety and compliance with local electrical codes.
- External Protection: Always ensure that appropriate overcurrent and short-circuit protection (e.g., circuit breakers or fuses) are installed upstream of the ATS, as this model does not provide these protections internally.
- Application Suitability: This ATS is suitable for various applications requiring uninterrupted power, such as elevators, water pumps, monitoring systems, fire fighting equipment, emergency power supplies, and office buildings.
Figure 8: Examples of suitable applications for the ATS.
9. Warranty and Support
For warranty information, technical support, or service inquiries, please contact your original point of purchase or the manufacturer directly. Ensure you have your product model number (TOQ3-4P/125) and purchase details available when seeking support.