UK We are opening a new business in the UK we have Power Question

[Paul Breen 2021]

we are considering to open a business in the UK and we have a machine with a 60HP hydraulic pump, it is 3 phase.

we are being offered a unit to use and the owner is telling us the supply is 3 phase with 30KVa

our question is will the supply be big enough to run the machine with the pump

 

[telectrix]

is the supply 30kVA per phase or total?

 

[Julie.]

It sounds like a single phase 80A supply to me.

Could be 3ph but that would be around 45A fuse, which sounds low even for a sub-let industrial unit or similar

 

[Lucien Nunes]

No, the supply is not big enough. The motor has a full load current of around 85 amps running (60kVA) but depending on the starting method, even a 100A (70kVA) supply might not be adequate. Where one large motor makes up much of the electrical load of an installation, its starting current is usually the main consideration, as the voltage drop during starting can cause other electrical equipment to malfunction.

You will need to liaise with the people on site who provide the supply (assuming it's not direct from the mains) and an electrician with experience in motor supplies.

 

[James]

60Hp is approximately 45Kva
therefore the supply is too small.

 

[brianmoooore]

The motor will probably run up to speed under the relatively light load of just pumping oil round in a circle, but, as the last post states, the supply's not big enough for the load, even when the pump's already running.

 

[pc1966]

Your best plan is to get some industrial electrician in to look at the setup in detail, it seems it is not enough but equally it is not a very "standard" limit (usually 63/80/100A so 43/55/69kW), so it might be fed from some incoming board in the unit.

Depending on the cost and limits for motor start up it might be worth seeing if you can have a soft-start system added to ramp up the hydraulic pump motor more gently and keep the surge current down. That might be cheaper than a supply with enough headroom!

 

[Paul Breen 2021]

Thank you all for the reply's its pretty much as i suspected myself, i calculated we need around 50KVA for this machine and to be able to keep the lights turned on

The machine has a programable softstart so we could ramp it up slowly which was my initial thinking but signing a 5 year lease with a 50/50 possibility to run this machine could be a mistake.
Once the motor has started the actual running load is quite low, it is basically ticking over to keep the oil flowing to 2 100mm cylinders that are shuttling against each other.

 

[David Prosser]

I’m quite intrigued as to what machine this is, two 100mm cylinders and a 60HP motor.

 

[brianmoooore]

High output hydraulic pumps are quite small. 2 x 100mm cylinders can shift a lot of oil, and the smaller the bore, the higher the pressure.

 

[David Prosser]

High output hydraulic pumps are quite small. 2 x 100mm cylinders can shift a lot of oil, and the smaller the bore, the higher the pressure.

That's exactly why I want to know what it is.

 

[Paul Breen 2021]

Hi All the pump is for a waterjet trimming machine, the hydraulic pressure operates the high pressure water intensifier.. hydraulic pressure in the middle cylinders and 4500Bar out of the end cylinders

 

[pc1966]

If the site is otherwise good for you then speak to the owner about getting an independent electrician in to look at what is possible and cost-effective in terms of supply upgrades.

If they have a beefy supply to the site but it is split on 45A MCB/MCCB/switched-fuse feeds then it might well be affordable to get a bigger supply share, they owner might even provide it as part of a 5 year lease to secure your custom.

 

[Paul Breen 2021]

If the site is otherwise good for you then speak to the owner about getting an independant electricin in to look at what is possible and cost-effective in terms of supply upgrades.

If they have a beefy supply to the site but it is split on 45A MCB/MCCB/switched-fuse feeds then it might well be affordable to get a bigger supply share, they owner might even provide it as part of a 5 year lease to secure your custom.

The site is more or less ok otherwise but I spoke with the owners yesterday and they are telling me a new supply from the sub-station would be the only option, depending if there is the extra available power there, he wasn't able to tell me anything more, apart from everything would be at our expense.
we are trying another couple of options in the area today so hopefully we can get something moving.

 

[pc1966]

OK, probably best to look around then. Good luck and let us know how you get on!