What is a Distro?

 Temporary Distribution Board, a Portable Power Box or a Site Distribution Unit can often refer to the same thing, we call them Distros for short. We go into depth about the different styles and what you need to know when looking to buy one.

Enclosures

There are a few different types of enclosures available and often the style of enclosure will depend on the size of the distro, but you will also need to consider the application.

Metal

Very large temporary distribution boards which are used to combine multiple supplies (like multiple generators) and distribute to other boards, typically dealing with in excess of 500A, are normally constructed of metal. This is due to the weight of the components which include MCCBs and thick copper bus bar. The metal enclosures are nearly always mounted in a frame which can be lifted by a crane or forklift as they are too heavy to safely lifted by hand. The metal frames not only help to transport and manoeuvre the distribution board, but protect the parts. BS7909 refer to these initial distribution boards as Intake Switch Units as they connect to the supply and protect both the inputs and outputs from overcurrent.

Metal distros are generally the most expensive, as they are used when dealing with high current. Smaller versions of metal distro can be used where the environment or designer required it; often construction or hazardous areas may require metal enclosures due to external influences.

Polypropylene Stackable

The typical style suitable for most needs; these are available in a variety of sizes. These can be used as an Intake Switch Unit from a single power source, a Central Distribution Unit or a Final Distribution Unit as referred to in BS7909.

Our polypropylene stackable distribution boards offer inputs from 500A powerlock down to 32A Three Phase. These all have the same standard footprint and while our off the shelf distros already have a huge choice of outputs, if you are looking for a unique configuration, fill in our Custom Distro Form and we’ll get a price over to you.

All of our Polypropylene Stackable distros have the options for:

• Input Isolation/Overcurrent across all phases and neutral
• Phase Sequence Indicator (illuminated before input isolation)
• M10 Earth Lug
• Indicator lights on outputs
• A choice of Fixed or Variable protection on three phase outputs

Polypropylene Single Carry Handle

More often found as a Final Distribution Unit (FDU BS7909), our single carry handle polypropylene distros are light weight and often fulfil more specific needs, such as a stage breakout distro like the 32A Single Phase 13A 4 Way Distribution Board (Black). However we can also use these to fulfil specific needs clients may have, such as this custom request for a 63A Three Phase to 3 x 32A Three Phase with Variable RCDs.

Injection Moulded

We use the PCE branded Imst and Ischl injection moulded distro boxes to create a huge variety of Final Distribution Units (FDU BS7909). These are a great low cost, prefabricated, stackable product that can allow us to produce a large number of small distros for a customer without impacting our in house fabrication team. As one of the UKs largest stockists of Imst components, we are able to offer a single custom unit next day or 100 custom units next week, typically from our own stock.

We have a large selection of off the shelf Imst distros, some of which are unique to us, like our IMST 32A Three Phase Thru to 2 x 32A, 4 x 16A RCBO.

Connections

Make sure your distro has the right outputs and protection you need as well as the right input for your supply.

This section is aimed more at those purchasing one off distros, if you are building a system with multiple distribution boards please get in touch with one of our Temporary Event Power Engineers to discuss how best to utilise and grow your kit.

Input

If you are looking to purchase a distro for a fixed location, the input to your distro is more than likely decided upon by the supply connection you have. Perhaps you are a caterer looking to streamline your operation for the upcoming festival season, you will very likely know the total consumption of your equipment and what power you will need.

If you’re not limited by the supply or you are not sure how much power you will be using, you will need to add together all of your potential draw. This means looking at all of those little labels and working out how much current will be flowing at any one time. Your labels will show consumption (power) in Watts or current in Amps. It is best to add them together in one of these 2, so if you only have Amps and want Watts, multiple the Amps by 240. If you only have Watts and you want Amps, divide by 240. Also, remember that 1kW is 1000W.

For example, you have a water boiler that is rated for 2.4kW. This is 2400 Watts. 2400 Watts divided by 240 is 10 Amps.

Once you have totalled up the amount of power (Watts) or current (Amps) you will need, the next step is to look at the future. Always allow for expansion, that way your distro will last for years to come. Listed below are the typical inputs and the amount of power (Watts) and overall current (Amps) base on single phase appliances equally distributed.

16A Single Phase 3840W, 3.840kW, 16A

32A Single Phase 7680W, 7.68kW, 32A

32A Three Phase 23040W, 23kW, 96A

63A Three Phase 45360W, 45kW, 189A

125A Three Phase 90000W, 90kW, 375A

Single Phase or Three Phase

The number of phases for your distro is very likely decided by your supply. If you are powered by a generator, you will either have a single phase or three phase generator. If you are using a mains supply, you will know if you have a three phase connection or not.

If you are not sure what connection you have, look for the colour of the connector and the number of pins. A standard single phase connection will use a blue socket and have holes for 3 pins. A standard three phase connection will use a red socket and have holes for 5 pins.

If you have any other combination of colour and holes in your socket, get in touch and one of our Engineers can assist you further.