Site Transformer question

[Gibboncore]

I moved to Belgium from the UK a couple of years ago and buy all of my power tools on my trips back to the UK as they are much cheaper!!!
However my hammer drill died last week mid house renovation and while I'm able to swap some of the work around I need to buy a drill... after recovering from the shock of looking at the prices over here I opted for a MAKITA HR2470T and bought it on line... it arrived in two days! Super fast delivery no problems there... only problem was I'd selected the 110v version not the 240v version... AAAAARRRRGGGGHHH!
My fault entirely but now I need to work out if it's makes sense to try and exchange it (if the company I bought it from are willing to do this) taking into account the cost of two lots of postal charges or buy a site transformer instead.
Problem is I'm not sure what size I need... I'm guessing that I might need a 3.3KVA 230V Portable Site Tool Transformer 2x 16A 110V Outputs http://www.amazon.co.uk/Made-3-3KVA...ef=sr_1_2?s=diy&ie=UTF8&qid=1342121885&sr=1-2 but I don't really want to lash out cash on guesswork so any advice greatly appreciated
Cheers

 

[RF Lighting]

Have a look on the drill and there will be a plate which gives you all the information about the drill.

On there should be the rating of the drill in watts. Once you know how much power the drill requires, you can work out how big the transformer needs to be.

 

[alumni]

It's only a few quid difference between the various options.
To me, it's better to pay the little extra and get the one with the high load capacity. Less likely to be found wanting.

 

[27neth]

Just send it back.. you are allowed to under the distance selling regulations. They have to take it back.. Im also sure they have to pay postage costs..
http://www.oft.gov.uk/OFTwork/consumer-protection/campaign11-12/kycr/kycr-buying-online/
John...

 

[Deleted member 174758]

The drill is under 1000 watts, do the most basic site transformer of around 1.5kVA will be more than man enough, however..... These transformers aren't light and shipping it will be an expensive PIA. I thinj the postrer who suggested exchanging it has it right. It'll probably cost less in postage.

 

[Gibboncore]

Thanks for all of the replies: some good advice there.
I have checked the plate on the drill and the rating is 7.5A and 780W: however all of the ratings for site transformers I have found on line only seem to only detail the amps so I'm not sure how this relates to the power rating on the drill.
Shipping the goods here in the first place was expensive, though cheaper than buying in Belgium, and doing it twice over will be twice as expensive.
It might even pay to try and buy a site transformer over here.
I'm not 100% clear how the distance selling regulations apply to postage cost which could well be the deciding factor!
Thanks again for all of the advice
Cheers
Micky

 

[Deleted member 174758]

all of the ratings for site transformers I have found on line only seem to only detail the amps so I'm not sure how this relates to the power rating on the drill.

Really? as far as I'm aware site transformers are rated by law in kVA (or kilavolt Amperes), not Amps. The conversion factor is about 0.8 and whilst an electrical engineer would explain that the conversion isn't absolute and depends on a number of factors, for practical purposes 0.8 suffices. In practical terms that means that a 3.3kVA transformer (the size youu need to run a 1/2in router) will deliver at peak about 2600 watts. Because transformers get hot it is normal to specify a transformer approximately 50% larger than you require for a given tool when using continuously - so that 3.3kVA transformer will support an 1800 watt tool for continuous running without overheating (which destroys the insulation on the transformer coils).

In your case the transformer you need to run your drill continuosly would be 0.8 (800 watts) x 1.5 x 1/0.8 kVA = 1.5kVA, or for intermittent use 0.8 x 1 x 1/0.8 kVA = 1.0kVA.

 

[Gibboncore]

all of the ratings for site transformers I have found on line only seem to only detail the amps so I'm not sure how this relates to the power rating on the drill.

Really? as far as I'm aware site transformers are rated by law in kVA (or kilavolt Amperes), not Amps.

I think is down to my lack of knowledge on the subject and the relationship between KVA and watts: the KVA was listed in the adverts

The conversion factor is about 0.8 and whilst an electrical engineer would explain that the conversion isn't absolute and depends on a number of factors, for practical purposes 0.8 suffices. In practical terms that means that a 3.3kVA transformer (the size youu need to run a 1/2in router) will deliver at peak about 2600 watts. Because transformers get hot it is normal to specify a transformer approximately 50% larger than you require for a given tool when using continuously - so that 3.3kVA transformer will support an 1800 watt tool for continuous running without overheating (which destroys the insulation on the transformer coils).

In your case the transformer you need to run your drill continuosly would be 0.8 (800 watts) x 1.5 x 1/0.8 kVA = 1.5kVA, or for intermittent use 0.8 x 1 x 1/0.8 kVA = 1.0kVA.

Okay now I understand the equation: so all I need to do is ensure that I'm covered for the continuous load but obviously if I can pick a transformer with a higher KVA then that is just future proofing for any higher draw tools I might buy at a later date.

Thanks again to everyone who has offered help and advice.

Cheers

Micky

 

[Deleted member 174758]

so all I need to do is ensure that I'm covered for the continuous load but obviously if I can pick a transformer with a higher KVA then that is just future proofing for any higher draw tools I might buy at a later date.

That's it. For site use a team of two joiners will never need more than 3.3kVA in my experience. Possibly the only people who need more than that are the guys running heavy breakers (Kangos), welders or big grinders - but then they often either run off the site box (which can be up to 40 or more kVA) or bring a petrol/diesel genny. Watch out for weight, though - a 1.1kVA is dinky and lightweight, a 3 kVA is darned heavy and a 5kVA induces hernias if shifted about a lot (and your shipping costs will reflect this)! You'll also find that a 110 volt extension cable is useful as shifting a box is another onerous task - they're best left plugged-in and power supplied via an extension cable (circa £25 or so)

 

[Gibboncore]

okay thanks very much for the advice: really appreciate it.
Cheers
Micky