Surge OI-1 surge voltage limiter overview

Purpose and principle of operation

The impulse voltage limiter OIN-1 is needed to protect electric networks with a voltage of 380 / 220V. These are standard voltages for power supply. Impulse power surges may result from lightning strikes. Because of them, a potential difference arises in the earth. In addition, they distinguish switching bursts in the network. They occur when you turn on or off powerful electrical appliances or group start consumers in an electrical installation. Switching pulses can occur when starting powerful electric motors or group starting pumping stations, as well as when switching on capacitor units.

How does a limiter work? Inside the SPE-1, varistors are installed. According to the principle of action varistors reminiscent of the arresters that were used previously. Therefore, the limiter is installed parallel to the protected circuit. If the voltage in the network exceeds the permissible (classification) voltage of the varistor, it begins to short-circuit the wires, thus averting the danger from electrical appliances connected after it.

Application area

Consider where the SPE-1 is used in practice. The use in real work of a surge voltage limiter is quite wide. It is installed in the introductory boards or consumer metering boards. At the same time, it is recommended to install it up to the counter in order to protect it. We will talk about how to correctly connect the SPE-1 to the shield below.

If you are going to build a house and connect the site to electricity - in the technical conditions for the connection, the need to install a surge protection device will be indicated. But such a requirement is introduced in most cases as prescribed in the PUE - with an air cable entry.

The official documentation on the use of the surge voltage limiter from the company "Energomera" refers to the fact that it is recommended for use in grounding systems TN-S, TN-C-S in a single-phase and three-phase network.

Specifications

Not a single description of devices is complete without information on technical specifications. SPE-1 has the following characteristics:

1. It withstands voltage up to 275V for a long time, at a standard frequency of 50 Hz.
2. Mounted on din rail.
3. The width is 17.5 mm, which coincides with the dimensions of a single-pole machine.
4. During operation, it consumes a current of 0.7 mA, at 275V.
5. It complies with GOSTs and has passed certification, therefore it can withstand pulses up to 10 kV, with Ikz = 5000A.
6. There is a version of OIN-1C, equipped with a light indicator of the presence of voltage in the network.
7. The terminal blocks allow you to connect conductive wires from 4 to 16 mm.

How to connect OIN-1 in the shield

This device has a number of functional analogs from all popular manufacturers of electrical engineering, therefore, their connection schemes are basically similar. In the official documentation, the connection diagram is not too obvious, it is presented in two versions and looks like this:

Pay attention to the first option - connecting a parallel protected circuit, and the second - in series with the disconnector. That is, as a result of the operation of the surge voltage limiter, the disconnector must break the power circuit in order to avoid ignition of the product and the flow of current through the electric arc.

But the above diagram is not at all clearly and clearly understood, and the question immediately arises of how to properly install the device. So check out a few examples connecting the surge protector to the mains.

The figure below shows a typical circuit of the conditions for connecting 3 phases. Here, the connection of voltage limiters to the meter is more clearly shown. In a three-phase circuit with a TN-S or TN-C-S grounding system, it is connected between phases, zero and ground. But connecting the OIN-1 after the counter is also acceptable as an additional level of protection.

Wiring diagram for an example of connection in a two-wire power supply network:

And finally, we will consider the circuits for four different power supply circuits (1 phase, 3 phases, combined and disconnected protective conductors), which are most common:

Important Note

We examined why OIN-1 is needed and how to install it. But without fail you need to add a note from the official documentation:

We are talking about connecting the machine to the gap of the supply wire in front of the limiter. This is necessary in order to short circuit in the pulse limiter, break the chains and prevent the negative consequences of the event.

Finally, we recommend that you watch the video, which explains how to connect the surge voltage limiter to the network:

This is where we end the description of the characteristics and connection rules of SPE-1. We hope that the prepared review was useful and interesting for you!

Surely you do not know:

• Classification of surge protection devices
• What is a power limiter
• How to deal with low voltage