Helping a Photovoltaic Connector Manufacturer Improve Mechanical and Electrical Reliability Testing

As photovoltaic systems continue to expand worldwide, the reliability of solar PV connectors and cable assemblies has become increasingly important.

A photovoltaic connector may be exposed to mechanical forces during installation, transportation, maintenance and long-term operation. Repeated tensile stress can potentially affect the connector, cable or conductor and may eventually lead to mechanical damage or electrical discontinuity.

For this project, a photovoltaic component manufacturer needed a dedicated testing system to evaluate the durability of its PV connectors under repeated tensile movement while carrying electrical load.

The customer's objective was not simply to measure the maximum tensile force of a connector. They needed to understand whether repeated mechanical movement could cause wire breakage, connector damage or interruption of electrical continuity.

The customer was looking for a testing solution that could combine mechanical tensile loading with electrical continuity monitoring.

Their key requirements included:

• Testing according to UL 6703 Clause 9.4
• Repeated reciprocating tensile movement
• Controlled and adjustable test force
• Accurate movement and force measurement
• Electrical continuity monitoring during testing
• Automatic test cycling
• Multiple specimens tested efficiently
• English-language PLC and touchscreen interface
• Reliable operation for laboratory testing

A conventional tensile tester could provide force measurement, but it would not necessarily provide the complete testing arrangement required for this particular PV connector reliability test.

This led to the need for a more application-specific testing system.

To address these requirements, Sinuo developed a dedicated UL 6703 PV Connector Reciprocating Tensile Testing System.

Rather than using a basic single-station tensile machine, we configured the equipment with four independent test stations, allowing multiple photovoltaic connector specimens to be evaluated efficiently.

The complete system combines:

PLC Control + Servo Motor Drive + Force Sensor + Precision Linear Slide + Electrical Continuity Monitoring

This configuration enables the machine to perform controlled vertical reciprocating tensile movement while monitoring both the mechanical and electrical behavior of the specimen.

Why Four Independent Test Stations?

One of the important design decisions for this project was the use of four independent testing stations.

For a laboratory performing PV connector qualification and reliability testing, testing one specimen at a time can significantly increase the overall testing period.

The four-station configuration allows the customer to:

• Test multiple samples efficiently
• Compare different connector designs
• Perform repeatability testing
• Improve laboratory utilization
• Reduce operator waiting time

The stations are independently configured, providing greater flexibility for different test samples and test programs.

For solar component manufacturers, connector reliability is more than a mechanical specification.

A connector may experience different forms of mechanical stress throughout its service life. If repeated tensile loading results in conductor damage or electrical discontinuity, the impact can extend beyond the connector itself.

Therefore, PV connector reliability testing plays an important role in product development, quality control and compliance verification.

The purpose of this project was not simply to build a machine capable of pulling a connector.

It was to create a testing platform that could answer a more important question:

That was the core requirement behind this UL 6703 testing solution.