Switch Characteristics Tester
The Switch Characteristics Tester (full name "High Voltage Switch Mechanical Characteristics Tester", also known as Circuit Breaker Dynamic Characteristics Tester) is a specialized instrument designed for detecting the mechanical dynamic characteristics of high-voltage circuit breakers. It integrates a computer, printer, measurement interface circuits, and an adjustable DC operating power supply into one unit. Based on a high-performance industrial embedded platform, combined with displacement sensors and anti-interference technology, it can resist strong electromagnetic field interference. It is a core tool for evaluating switch mechanical performance in production inspection, acceptance testing, and preventive testing of high-voltage circuit breakers.
Core Measurement Parameters
The core task of the Switch Characteristics Tester is to accurately measure the following key parameters:
Time Parameters: Closing (opening) time, re-closing time, three-phase non-simultaneity, same-phase non-simultaneity, bounce time, gold-plated short circuit time, no-current time
Speed Parameters: Opening speed at contact separation, closing speed at contact touch, maximum speed, average speed
Travel Parameters: Total travel, open distance, overtravel, rebound travel (bounce travel)
Bounce Parameters: Bounce time, bounce count, bounce amplitude
Electrical Parameters: Coil current waveform, coil resistance
Dynamic Curves: Time-travel curve, speed-travel curve, current waveform curve
In simple terms, the Switch Characteristics Tester uses "time" to see if the switch operates promptly, "speed" to see if the action is forceful, "travel" to see if the contact movement is complete, and "bounce" to see if closing is stable.
Working Principle
The Switch Characteristics Tester adopts high-speed data acquisition and multi-channel synchronous triggering technology:
Signal Acquisition: Through 12 independent metal contact time channels and displacement sensors (linear sensors, rotary sensors, or acceleration sensors), it synchronously collects time, travel, and speed signals during the opening and closing operations of the circuit breaker.
Operation Control: It has a built-in isolated adjustable DC power supply (typically DC 30~270V continuously adjustable, with instantaneous current up to 20A), directly controlling the circuit breaker for opening, closing, and re-closing operations.
Data Processing: Using an embedded industrial control platform and high-speed data acquisition technology, the time measurement accuracy can reach 0.01ms. A single opening and closing operation can complete the synchronous recording of time, travel, speed, and coil current parameters for all breaks.
Result Output: It displays parameter values and dynamic curves on a color LCD touch screen, supporting on-site printing, USB drive export, and PC communication.
To adapt to strong electromagnetic interference environments such as substations, the instrument adopts anti-interference technologies including channel induced voltage discharge protection circuits, floating design, large-area grounding, and digital filtering, ensuring reliable operation in 500kV and even 800kV substations.
Key Technical Parameters
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Parameter Typical Range
Break Test Channels 6~12 independent metal contact time channels
Time Measurement Range 0.01ms ~ 20000ms
Time Measurement Accuracy ±(0.05%t+0.1)ms
Time Resolution 0.01ms (within 200ms)
Speed Measurement Range 0.001 ~ 25.0m/s
Speed Resolution 0.01m/s
Travel Measurement Range Depends on sensor, up to 1000mm
Travel Resolution 0.1mm
Built-in DC Power Supply DC6~270V continuously adjustable, ≤20A (short-term)
Coil Current Measurement 0~30A, resolution 0.01A
Data Storage 60~500 groups
Power Supply AC 220V±10%, 50Hz
Operating Temperature -20℃ ~ +50℃
Relative Humidity ≤90%RH, non-condensing
Weight Approximately 5~12kg
Main Functions
Compatibility with Multiple Switch Types: Can test various voltage levels of high-voltage circuit breakers such as low-oil, multi-oil, vacuum, SF6, as well as GIS combined appliances, pole-mounted switches, contactors, relays, etc.
Multiple Operating Modes: Supports various operating sequences such as single close, single open, close-open, open-close, close-open-close, etc.
Multiple Trigger Modes: Supports internal trigger (the instrument issues close/open commands), external trigger (external control energizes the coil), manual trigger, and other trigger modes.
Low Voltage Operation Test: Using the built-in adjustable DC power supply, it can perform low voltage operation tests and mechanical life tests on circuit breakers without the need for external secondary power on site.
Customizable Speed Definitions: Provides a universal speed definition template, allowing users to edit and save speed definitions for various switch models, with built-in speed definitions for multiple conventional types of circuit breakers.
Dynamic Curve Analysis: Can dynamically analyze the relationship between time, travel, and speed at every movement point of the circuit breaker, displaying time-travel curves, speed-travel curves, and current waveform curves.
Data Management: Built-in large-capacity memory, supports USB drive export and RS232 interface for PC communication, and can print all data and motion curves on-site.
Safety Protection Mechanisms
Delay Protection: Automatically cuts off the coil voltage after the circuit breaker operates, protecting both the circuit breaker equipment and the tester.
Induced Voltage Resistance: The test channels have the ability to resist on-site induced voltage interference, withstanding up to 15kV induced voltage.
Dielectric Strength: The power input to the chassis can withstand a 1.5kV 1-minute withstand voltage test.
Insulation Resistance: >2MΩ
Typical Application Scenarios
Factory Inspection: Detection and verification of mechanical characteristic parameters during the production of circuit breakers.
Acceptance Testing: Before new circuit breakers are put into operation, verify that mechanical characteristics meet standard requirements.
Preventive Testing: Regularly inspect circuit breakers in operation to assess the trend of mechanical performance degradation.
Fault Diagnosis: Conduct targeted testing when circuit breakers experience failures such as refusal to operate, maloperation, abnormal operating times, etc.
Operating Voltage Test: Test the operating characteristics of circuit breakers at different voltages to verify the reliability of the operating mechanism.
Mechanical Life Test: Evaluate the durability and reliability of mechanical components of circuit breakers.
Executive Standards
GB/T 1984-2014: High-voltage AC circuit breakers (current national standard)
DL/T 846.3-2017: General technical specifications for high-voltage testing equipment - Part 3: High-voltage switch comprehensive tester (current industry standard)
GB 10963-1999: Circuit breakers for overcurrent protection for household and similar installations
Main Brands
Domestic Brands: Wuhan Hertz Electric, Nanjing Saihao Electric, Yangzhou Guohua Electric, Wuhan UHV Electric, etc.
Imported Brands: Megger (UK), OMICRON (Austria), Doble (USA), etc.
Compared with several instruments you have known before, the positioning of the Switch Characteristics Tester is significantly different:
Dielectric Loss Tester: Measures tanδ and capacitance of insulating materials, focusing on insulation condition diagnosis.
Transformer Turns Ratio Tester: Measures winding turns ratio and connection group, focusing on winding structure verification.
Loop Resistance Tester: Measures micro-ohm level contact resistance of conductive loops, focusing on the quality assessment of conductive connections.
High Voltage Wireless Phase Tester: Measures phase difference and phase sequence of high-voltage lines under live conditions, focusing on phase consistency verification.
Switch Characteristics Tester: Measures mechanical dynamic characteristic parameters of circuit breakers, focusing on mechanical performance evaluation.
The Switch Characteristics Tester is the only instrument dedicated to mechanical motion characteristics. It comprehensively evaluates the operating performance of circuit breakers through parameters such as time, speed, and travel, making it a key testing tool to ensure reliable operation of switchgear in power systems.
