When installing an inverter in your home?

The unreliable electrical supply in South Africa is a concern for homeowners. There are many options for alternative power being offered, for example; solar panels, wind turbines, solar water heating and inverters. Also, there are many low tech, or DIY devises which can reduce your reliance on the conventional electrical supply. The inverter, with battery back-up can be an economical method to store a limited amount of electricity, for use when the municipal supply is down.

In the home, when the mains supply is available, an inverter takes AC electricity from the grid, converts it to DC electricity and stores it in batteries. Then, when there is no mains electricity, the inverter converts the DC electricity back to AC and powers the appliances which have been connected to it.

There are two options a homeowner can consider, when deciding on an inverter for a home; a freestanding “portable” option (plug n play) and a fixed option (hardwired). 

The freestanding or Plug n Play option:

The unit is housed in a self-contained box including the batteries. It can be moved around the home, but must be permanently plugged into a normal socket, to maintain the charge and the life of the batteries. These systems are readily available from many suppliers. They usually come with one battery (1200 VA), or two batteries (2400 VA). The costs vary, depending on the specifications, from approx. R 5000.00 to R 10000.00 (Price is dependent on specifications, supplier and current cost).

The number of appliances that can be connected to this option is limited. The specification of the inverter, the capacity of the batteries and the electricity used by the connected equipment, will determine what can be powered at one time. Usually; a light, the TV and a devise or two. The lights, or equipment to be used, have to be plugged in manually.

The hardwired option:

The system is installed permanently, close to the electrical distribution board. It’s bolted to the wall with the batteries mounted in a rack below. The room should be cool and ventilated, for safe optimum performance. The inverter is permanently wired to the distribution board and the plugs, lights and equipment you choose, are permanently connected. When the mains electricity is off, the lights and appliances connected can be used, as normal, as the selected electrical circuits are permanently connected.

The installation can be sized depending on your requirements. A small unit starting at 3 kVA, approx. 10-12 Amps, can run the essential loads to a medium size home. For either a 24 Volt, 2 battery, or 48 Volt 4 battery the approx. cost would be R 30 000.00 – R 40 000.00 including installation, depending on the specific requirements (Price is dependent on specifications, supplier and current cost).     

There are three types of inverters, either a pure sine wave, modified sine wave, or square wave inverters. For precise equipment that may have delicate electronics or audio devices, the pure sine wave inverter is preferred. However, for the homeowner, ordinary equipment and appliances, like tablets, televisions, and cameras work well with a modified sine wave inverter.

The batteries used with an inverter are important. Deep cycle, lead acid batteries are designed to be repeatedly discharged to at least 50% of their capacity, which makes them suitable for home power use. A car battery is not appropriate and should not be used.

For further information on inverters, contact: Bernard Heritage – ACDC Express:

Tel.:  082 453 5939

E-mail.:  bernardh@ACDCExpress.com

Website:  http://www.acdc.co.za