We have recently identified the types of load, qualified how much load we have to correctly identify our UPS, spoken about battery extension modules and more. Today onto three-phase Vs single-phase power.

In the UK, 3 phase power is usually 400V, whereas 1 phase power is 230V. The former is a way to deliver power to larger loads and the latter is more commonly found where smaller loads are present, such as domestically.

To keep it nice and simple, depending on whether the power planned to supply a UPS system is 3 or 1ph, will make the decision for you as to what type of input your UPS will have. This isn’t necessarily always the case, as it may be a decision for a client to change the electrical infrastructure to a more suitable type. This can be due to a smaller or larger power demand by the critical load than the supply type is suitable for.

An example of this may be that the load exceeds 20kW in capacity but was suggested to be supplied from a 1ph supply. It’s unusual to have 1ph UPS exceed 20kW, therefore it may be best to change to a 3ph supply and in turn, utilise a 3ph UPS. The converse would be that a load is under 6kW, but was planned to be supplied by a 3ph supply. It is more likely that the load would be suitable for a 1ph supply type.

The output of the UPS to the load is also important to identify. Would the critical load usually be powered by a 1 or 3ph supply? When you can answer that, you can identify the UPS output type.

It’s uncommon to see UPS with 1ph input and a 3ph output. Having said that, they are advertised as solutions from time to time by manufacturers, so there is a market for it, somewhere!

More commonly, UPS are either 1/1, 3/1 or 3/3ph in design. There is a small window for 3/1ph systems to be applicable, usually between 10-20kVA. 20kVA and below could be 1/1ph and 10kVA and above could be 3/3ph.

If your load is around 10-20kW you fall in a very flexible design spot for UPS protection, as you can utilise all 3 common variants. This will help to reduce the need to change electrical infrastructure to accommodate the UPS. Outside of that, UPS is basically an intersection within the electrical power pathway to add the UPS and batteries as a stop gap for upstream power problems, therefore by selecting the correct product, no electrical infrastructure changes should be necessary.

When replacing existing UPS systems, power demands could have changed over time. Additional load added or reduced as deemed necessary by the client. When this happens, electrical infrastructure changes may be required or perhaps utilising a flexible UPS system to best accommodate both the infrastructure and the load. If this is the case for you, get in touch with our sales department. Following a site survey, we can identify the most suitable product for both.