Ask a Tradesman
Is there a 3 phase inverter out there that can manage a possible output of up to 60.000 watts for a tanning shop?
I know we can change the power supply via energy company but this is been quoted as a 6 week minimum wait and would rather get set up quicker than this. Electrical needs as follows which has been copied and pasted from a sunbed website:
Most people underestimate this, even some electricians if they haven’t installed a sunbed previously. As a
rough guide, a 200 Watt lamp uses about 1 Amp of electrical current, so a 40 tube 200 watt sunbed uses
around 40 Amps, which equates to 9.6 Kilowatts. This means that the cable supplying power from your
fuseboard to your sunbed room needs to be 10mm (size in cross sectional area) which is thicker than most
shower or cooker cables. Its amazing how many people think
that the sunbed can be simply plugged in to a conventional socket! A 13 Amp plug has a maximum power
capability of 3 Kilowatts before the fuse will blow.
What’s more, a sunbed is what’s called an inductive load. This means that when it starts up, it draws around
10 – 20% more current during the first few seconds, just like an electric motor. Many electricians do not realise
this, and although it does not affect the cable size required, it does affect the size of the circuit breaker (fuse)
in your fusebox. If the 40 tube (40 Amp) sunbed in the example above was supplied via a 45 Amp circuit
breaker, it would trip out on start up, giving the impression that the sunbed was faulty.
There are two solutions: one is the obvious, to fit the next size up circuit breaker. Unfortunately, this is either
50 Amps, or 63 Amps. The wiring regulation do not recommend a 63 Amp breaker to protect a 10mm cable,
as it results in a mismatch that can be potentially a fire hazard, so a 16mm cable would be required, which is
much more expensive, and cumbersome to route through your shop due to its larger physical size.
The other option is to use a Type “C” circuit breaker in the fuseboard. Electricians call these ‘motor start
breakers’ and these allow a higher initial start-up current to flow without tripping, as used on industrial electric
motors. Problem solved!
Leisure Centres and hotel chains may also insist on having what is known as an RCD, or Residual Current
Device fitted, also called RCB. This is similar to a circuit breaker and provides additional electric shock
protection to the sunbed user. Whilst this is not yet mandatory in the Wiring Regulations, larger companies
(and most suppliers of new commercial sunbeds) tend to insist on installing them to reduce the potential of
electrocution. In our current litigation-crazy society, this is likely to become more common in the future, and so
fittng a RCDis recommended
60,000 watts are you sure, thats a huge load? Are you sure its not 6000 watts i.e. 6 Kilowatts?
If it is 60kw then it will excced the maximum load that you can draw from a single phase 100amp service any way! so the meterr will catch fire if you connect 60Kw to it!
For 60Kw you'd need ten of these inverters;
Thats £10,000 in inverters to start with. They then need wiring up etc, its mega-money.
Do yourself a favour and get an electrical engineer in to design what you need properly from day one, as there is no cheap fix for the problem you have.
To operate 4 beds simultaneously (no diversity allowed) you will exceed the single phase 100amp fuse rating, so need a 200 or 300amp service installed by the Distribution Network Operator.
Trying to operate 4 x 9.6kw loads via inverters on a single phase supply head is suicide! Hope you have good insurance as your insurer will not payout in the event of a fire.
All the additional info you have provided is correct and will need to be done anyway. The flaw is that 3phase is a vectorial sum of the single phases so a 9.6kw single phase load is not a 3.2kw 3 phase load!
As I say, get an electrical enginner to design what you need properly, so that its installed right first time.
Answered 19th Mar 2012
once you have three phase supply it problem sorted.you know how many sun beds will be in total and then you know the maths to be done.simple!
Answered 21st Mar 2012
A good project need good experienced designer to guide from the 1st step.
Online free help could give some direction but looking at your date I advise to call EON/EDF or network people to submit your total demand and they will help you to guide with project cost.
Please do not connect anything over the limit as I have seen some businesses in past and closed down by LFB and Local authority.
Good luck with cable Network Company.
Answered 6th Nov 2013