IR4053 Insulation Tester

Instrument Safely Measures Insulation Resistance During PV Generation

Hioki is pleased to announce the launch of the Solar Power System Insulation Resistance Tester IR4053. The new instrument features a photovoltaic resistance function that can be used to safely and accurately measure solar power systems while they continue to generate electricity during daylight hours.

The development of the IR4053 took the form of a three-way joint research project undertaken with the Nagano Prefecture General Industrial Technology Center under the guidance of Director Masakazu Yokomichi and NextEnergy & Resources Co., Ltd.

Role of Insulation Resistance Testing
Insulation refers to a state of high electrical resistance in which current does not flow. Insulation resistance provides a quantitative expression of this state in which current does not flow, with higher values indicating better insulation and superior safety.

With electrical devices and equipment, a lack of adequate insulation can lead to a short-circuit, posing serious hazards such as fire and electric shock. Consequently, workers perform insulation resistance testing to prevent such hazards. Insulation resistance meters are used to accomplish this type of testing, making them an essential tool in maintenance work that involves electrical equipment, among other tasks.

Insulation Resistance Issues in Solar Power Systems
The number of solar power systems has been increasing in recent years, presenting new opportunities for measuring the insulation resistance of those systems in the course of their maintenance and management. This situation has led to the ongoing development of maintenance inspection guidelines that govern how insulation resistance testing is carried out.

However, there are issues with insulation resistance and solar power systems. Since these systems generate electricity during daylight hours when the sun is out, mistaken shorting of a string of photovoltaic cells during testing work could result in a number of hazards such as an arc discharge*. In addition, when using conventional insulation resistance measuring instruments in a method that does not involve shorting strings of photovoltaic cells, the voltage generated by the string* affects measured values, making it impossible to obtain an accurate measurement in some cases.

The newly developed IR4053 features a photovoltaic resistance function for measuring solar power systems. This capability makes it possible to measure insulation resistance accurately without shorting strings of photovoltaic cells and without risking accidents such as arc discharge events, even as the system continues to generate electricity during daylight hours.

*Arc discharge: A type of insulation breakdown in which current flows through the air, causing high temperatures and a flash of light.
*String of photovoltaic cells: A group of multiple photovoltaic modules (solar panels) that have been wired together in series to generate power collectively.

* Maintenance and management of solar power systems
* Installation of solar power systems, etc.

1. Photovoltaic resistance function for safe, accurate measurement of solar power systems
The IR4053 features a photovoltaic resistance function that makes it possible to measure insulation resistance values safely and accurately without shorting strings of photovoltaic cells, even while the system continues to generate electricity during daylight hours. The instrument also includes a conventional insulation resistance measurement function, enabling its use as a single-device solution for measuring equipment such as power conditioners. The device provides two photovoltaic resistance function measurement ranges (500 V and 1,000 V) and five insulation resistance measurement ranges (50 V, 125 V, 250 V, 500 V, and 1,000 V).

2. Sufficient speed to measure insulation resistance of solar power systems with numerous measurement locations
The photovoltaic resistance function displays measurement results within 4 seconds. In addition, normal insulation resistance measurement displays results in 1 second. This level of speed makes it possible to complete measurement tasks quickly, even when numerous locations must be measured.

3. Ability to measure voltages of up to 1000 V DC in open-circuit voltage inspections at megasolar installations
Today’s solar power systems continue to grow larger in a trend that is typified by megasolar installations, and these larger systems generate electricity at higher voltages. When investigating the performance of solar panels, it is necessary to measure the open-circuit voltage of components such as strings. The IR4053’s voltage measurement function supports measurement of up to 1000 V DC.

IR4053 Product Video


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