User Manual: Three-Phase Adjustable Over/Under Voltage Protector

1. Introduction

The SINOTIMER STVP series automatic over-voltage and under-voltage protector is designed for three-phase 3*127V/220VAC power systems with a rated working current of 80A. This device provides essential protection for electrical equipment by instantaneously cutting off the power supply when over-voltage, under-voltage, or over-current conditions are detected. Once the circuit voltage returns to normal, the protector automatically restores power, ensuring continuous operation and safeguarding your appliances from damage.

This protector integrates multiple protection functions including over-voltage, under-voltage, over-current, three-phase current (voltage) imbalance, phase sequence (reverse phase), zero-break, and phase-break protection. It also features voltmeter and ammeter functions, and the ability to restore factory settings. The device offers comprehensive features, stable performance, and ease of operation.

A detailed user manual in PDF format is available for download: User Manual (PDF)

2. Key Features

• Over-voltage protection
• Under-voltage protection
• Over-current protection
• Automatic recovery
• Voltage display (separate ABC phase voltage measurement)
• Ampere display (separate ABC phase ampere measurement)
• Three-phase ampere unbalance protection
• Phase sequence protection (reverse phase protection)
• Zero line break protection
• Phase failure protection
• Fault inquiry function
• Rotation display of voltage and current for each phase
• Adjustable over-voltage protection value and recovery value
• Adjustable under-voltage protection value and recovery value
• Adjustable over-current protection value and action time
• Adjustable 3-phase ampere unbalance protection value and action time
• Adjustable delay time after power-on
• Adjustable fault recovery delay time
• Factory data reset function

3. Product Specifications

4. Safety Information

• Installation and maintenance should only be performed by qualified electricians.
• Ensure the power supply is disconnected before any installation or wiring work.
• The device does not provide overload or short-circuit protection. It must be used in conjunction with appropriate external circuit breakers (e.g., C45, C65 mini circuit breakers) for comprehensive protection.
• Verify all wiring connections are secure and correct before applying power.
• Do not operate the device in wet or hazardous environments.

5. Installation

5.1 Physical Dimensions

5.2 Mounting

The protector is designed for 35mm DIN rail installation. Snap the device onto the DIN rail securely.

5.3 Wiring Diagram

Connect the input and output terminals as shown in the diagram below. Ensure correct phase (L1, L2, L3) and neutral (N) connections. The input terminals are located at the top, and output terminals at the bottom.

6. Setup and Configuration

To enter the setting mode, press and hold the SET button for 3 seconds. Then, continuously press SET to cycle through the parameters. Use the ▲ and ▼ buttons to adjust the values. When "ENd" appears, press SET again to save the data and exit the setting mode.

If no operation is performed within 10 seconds after pressing SET, the device will automatically exit the setting mode, and any unsaved changes will be lost.

6.1 Parameter Settings Table

6.2 Factory Reset

To reset the device to factory settings, press and hold the ▲ and ▼ buttons simultaneously for 3 seconds.

7. Operation

Once installed and configured, the device will continuously monitor the three-phase power supply. The LCD screen will automatically rotate to display the real-time voltage and current for each phase (L1, L2, L3).

In case of an over-voltage, under-voltage, or over-current event, the protector will automatically trip and cut off the power supply to protect connected equipment. After the fault condition clears and the recovery delay time has passed, the device will automatically restore power.

8. Troubleshooting

8.1 Fault Inquiry

If a fault occurs, the device will display an error code (E0). You can press the ▲ button to query the last 5 fault records (E1-E5). The display will indicate:

• ">U" for overvoltage events.
• "<U" for undervoltage events.

8.2 Phase Sequence Error

If the LCD displays "ABC" character, it indicates a phase sequence error. To correct this, arbitrarily reverse any two of the three phase lines (L1, L2, L3) at the input.

9. Maintenance

• Keep the device clean and free from dust and moisture.
• Regularly check wiring connections for tightness and signs of wear or damage.
• Do not attempt to repair the device yourself. Refer to qualified personnel for service.

10. Warranty and Support

For technical support, inquiries, or warranty claims, please contact the distributor: