RSA Electrical

Electrician in Claremont, Constantia, Newlands, Ronderbosch : Rob 071 533 6466

Inverters : Battery Back Up Systems

How do these systems work?

The unit is permanently connected to utility power so that while mains is present the extra large built-in battery charger recharges the batteries and keeps the batteries fully charged until a power failure (load shedding) occurs.

The equipment you want to back up is also permanently connected via the system. Back up means the designated circuit / equipment has a backup supply.

In case of a power failure the backup system automatically switches over, via an extra fast transfer switch to the inverter, which will continue to provide power to the equipment within 15 msec. This is not as fast as a UPS system, which is instantaneous.

This is extremely fast and standard equipment like TVs, DSTV decoders, microwaves, fans, etc. are unaffected. The sinewave systems can also backup computers but it is possible that a very small percentage of computers could reset during the switchover time.
Also wifi routers can reset.

When utility power returns, the whole procedure is reversed and the unit will switch back to utility power and will automatically start re-charging the batteries. 

Your equipment remains connected to the system even when power is restored. The whole process is fully automatic.

The advantage of this that you don’t have to install a noisy generator. Generators need constant refilling and maintenance and are not ideal for residential areas or for small businesses where noise and pollution from the exhaust are a problem.

Our systems offered here are a pure sinewave inverter; with a built-in battery charger, automatic changeover switch and a large battery bank. There is a small fan on the inverter. We do not recommend or install modulated sine wave inverters, which are cheaper and have limitations.

FAQ: How many hours of power can a multi-function inverter with battery storage provide?

This depends on the load. By reducing your load during a power outage, the batteries will last longer. 
For example, using 1kW of power on a 1kWh system will deplete the batteries in an hour, but by turning off non-essential equipment and reducing the load to 500W the system will last 2 hours. 
Typically, battery back-up systems should be sized to combat load shedding which occurs in up to 2.5-hour segments and up to 3 times a day (Stage 4). The battery back-up system should be sized sufficiently to have time to charge fully between load shedding periods.

FAQ: Does the battery back-up system automatically switch to battery power when the grid falls away and does it charge the depleted batteries when the grid returns?

Yes, the system will seamlessly switch to battery back-up when the grid falls away and automatically use the grid power as soon as it becomes available to recharge the depleted batteries. 

There is no down-time for your essential equipment when load shedding kicks in.

Optimise your power usage.

Only keep the basic/necessary devices running. For instance your geyser does not need to be on backup as it consumes a lot of power and you will only lose 2°C in water temperature during the 2-2.5 hours load shedding by keeping off the backup system.

By installing LED lights (remember incandescent and halogen downlights won’t do) all your lights can be added on backup power.

We recommend quality LED lamps such as Philips, Synergy. Also remember if you are upgrading to led lamps then you must upgrade your dimmers and make sure the led lamps are dimmerable and have the correct colour.

An induction or gas hob should be used for cooking while heating food should be done using a microwave oven.

Fridges and freezers can be powered by backup power, but normally it is not necessary if the unit’s doors stay closed.

AV systems and PCs are not very power hungry and can easily be powered by a backup system leaving you with those luxuries during load shedding.

Note: we do not do solar installations.

Contact RSA Electrical for a site visit (R620 ex Vat) and a subsequent quotation.