Please explain the safety standards.
When mounting a photocoupler onto an apparatus as a means of insulation for safety reasons such as protecting you against an electric shock, it may be subject to various regulations in the aspect of safety standards. A broad range of matters have been standardized as different standards, including the safety provisions and criteria. The safety standards are divided into the apparatus standards and part standards; the former apply to an entire set and the latter to each component part, respectively.
| Safety Standards | IEC | EN | Standards | |
|---|---|---|---|---|
| The Standards of Equipments | The Standards of Office Equipment etc. | IEC60950 | EN60950 | UL1950 |
| BS EN60950 | ||||
| DIN EN60950 etc. | ||||
| The Standards of TV,VCR etc. | IEC60065 | EN60065 | BS EN60065 | |
| DIN EN60065 etc. | ||||
| Parts Specifications | The Standards of Photocoupler | EN60747-5 | UL1577 | |
These safety standards have been uniquely provided in each country, based on the international standards, IEC. There are typically the UL in the U.S.A., VDE in Germany, BSI in Britain, and so on. The test method to measure insulation performance between input and output, and its judgment criteria have been defined quite differently in the UL Standards and the VDE Standards.
- UL: Dielectric strength test based on the extent of dielectric breakdown when a high voltage is applied.
- VDE: Partial discharge test to determine the insulation performance by the fact that the electric charge produced by partial corona discharge is 5 pC or lower.