Using reserve power in the electricity network

You can use reserve power to safeguard the distribution of electricity in the event of a disturbance

For example, a generator could be installed on a property or farm. UPS devices can ensure a fully uninterrupted supply of power to devices from the onset of a power cut until the reserve power generator has started up.

When you connect reserve power, you must ensure that the reserve power equipment is installed in accordance with the applicable regulations. Incorrectly connected reserve power devices could pose a fatal hazard to residents in the building and personnel repairing the electricity network. They may also cause damage to devices connected to the electricity network.

Keep the following matters in mind when you connect or plan to connect a reserve power device:

  • All installation of reserve power devices must be carried out by an authorised electrician.
  • All devices must be installed in the property's electricity network after the electric meter.
  • For the safety of our fault repair personnel, it is important to ensure that the electricity network supplied with reserve power is disconnected from the network company's distribution network. For this reason, the reserve power equipment must have a switch that prevents it from operating in parallel with the distribution network.
  • There must be adequate isolation, and the recommended method is to use a three-position change-over switch that disconnects one supply before connecting the other. Note: Placing the main switch in the 0 position does not provide adequate isolation. Your contractor can provide further information on the isolation requirements and on connecting a reserve power generator. Your contractor will find the specifications in the SFS 6000-5-551.6/7 standard and on ST card ST 52.40.
  • While the reserve power system is in operation, you are responsible for the quality of the voltage, and you should take care to ensure this when you choose a device.
  • The reserve power generator should be serviced regularly.

Reserve power used at the same time as mains power

The network company must approve reserve power generators that can be used at the same time as normal mains power. 

Examples of reserve power that can be used at the same time as mains power include synchronisation reserve power generators, parallel operation and dual operation. These are used for purposes such as reducing the maximum current required from the electricity network while large loads, such as grain dryers, are in operation.