Surge protective devices for the power supply

Type 1, type 2 and type 3 surge protection for power supplies

Type 1, 2, and 3 surge protection protects against malfunctions and defects caused by overvoltages. In the absence of effective protection, high costs are likely due to system failures. In the worst-case scenario, the affected equipment will need to be repaired or replaced. The multi-stage concept from Phoenix Contact provides effective protection for systems and devices.

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Type 1, type 2, and type 3 surge protection

Type 1, type 2, and type 3 surge protection

The difference between type 1, type 2, and type 3 surge protection

Type 1 combined lightning current and surge arresters are used in unmetered areas. They must satisfy the most stringent requirements, as they are supposed to protect against the effects of direct lightning strikes. The demand placed on the short-circuit current rating is very high in a typical main distribution installation environment. In order to be able to meet these requirements, powerful technology, such as spark gap technology, is required.

Type 2 surge protective devices with a low discharge capacity are installed in the metered area. They are generally installed in subdistributions or machine control cabinets. These surge protective devices must be able to discharge induced overvoltages from indirect lightning strikes or switching operations, but do not have to handle direct lightning strikes. Discharge technology with fast response behavior – such as varistor technology – has proven itself here.

Type 3 surge protective devices with the lowest discharge capacity, also known as device protection, are installed as close as possible to the end device. Special surge protective devices are needed for signal lines. These are also installed immediately upstream of the end devices to be protected. The devices are available in a wide range of designs to suit the various different installation environments. In addition to standard DIN rail mounting, there are products for installation in sockets or for direct mounting on a PCB of the end device.

Technologically speaking, type 3 surge protection is similar to type 2, which is based on varistors, but the requirements concerning discharge capacity are even lower compared to type 2. Type 2/3 surge protection is provided above all on cables that lead into a building from the outside.

Standards for type 1, type 2, and type 3 surge protection

Surge protection standards

Standards and directives for type 1, type 2, and type 3 surge protection

National and international standards provide a guide to establishing a lightning and surge protection concept as well as the design of the individual protective devices. A distinction is made between the following protective measures:

  • Protective measures against lightning strike events: stipulated in lightning protection standard IEC 62305. A key component of this is an extensive risk analysis with regard to the necessity, scope, and cost-effectiveness of a protection concept.
  • Protective measures against atmospheric influences or switching operations: stipulated in IEC 60364-4-44. In comparison with IEC 62305, it is based on a shortened risk analysis and uses this as the basis for deriving corresponding measures.
  • According to DIN VDE 0100-443/-534, surge protection is mandatory in private residential buildings and small commercial buildings. Systems commissioned after 2018-12-14 are to be planned and installed solely in accordance with the two new standards. DIN VDE 0100-443 governs when surge protection is to be installed. DIN VDE 0100-534 describes how and which protective measures are to be installed.
  • DIN EN 61643-11 sets out the requirements and test methods for surge protective devices in low-voltage power systems.

In addition to the standards mentioned, you may have to observe other legal and country-specific stipulations, which often make the use of surge protection a compulsory requirement. Our experts will be happy to advise you on this.

The Safe Energy Control product family

The Safe Energy Control product family

The Safe Energy Control product range

The SEC (Safe Energy Control) product family is synonymous with exceptional durability and maximum performance in the field of lightning and surge protection. With technologically leading spark gaps, we ensure the uninterrupted protection of your system. The direct coordination between spark gap and varistor in the special combined lightning current and surge arrester ensures that your sensitive devices are given the maximum protection – even in the event of dynamic overvoltages. At the same time, the family offers the first type 3 surge protective device in the world to feature Push-in connection technology for quick and easy installation. The uniform, compact design and operation without the need for a backup fuse completes the SEC family.