OT: HP of an electric motor?

I vaguely remember that 200 bhp is approx 150kw.

Tim Hobbs

'58 Series 2 '77 101FC Ambulance '95 Discovery V8i

Twas Tue, 1 Jul 2003 20:32:09 +0100 when "David_LLAMA4x4" put finger to keyboard producing:

1 horse power is 745.6999 watts. Multiply watts by 0.001341022 to get HP horse power.

And which horse was it that set the standard for the power this animal could produce? Irish Draft horse or Dartmoor Pony?

;o)

-- Regards. Mark.(AKA, Mr.Nice.) ___________________________________________________________ "To know the character of a man, give him anonymity" - Mr.Nice.

mr.niceATsofthome.nethttp://community.webshots.com/user/mrnice106___________________________________________________________

3HP would be about perfect as I am stuck with single phase. They wanted about £5k to get 3 phase up to us and the stud farm down the road!!!

Just to confuse the issue the motor is marked as 7.5Amp but 750 watt and

230 volts ??? The maths then works out: 230v x 7.5amp x .001341 = 2.3 hp. Might just do BUT why is there a 750 watt marking on the motor??? Only 1hp!!! Not enough.

A clue to anyone who messes with such items is that it has a big capacitor fitted to aid starting. Would a 750 watt motor really need this?

Still in a pickle.. maybe I should just bolt it to the machine and see if it runs...

David LLAMA 4x4

Strange. Over here (Belgium) we used PK (PaardeKracht = HorsePower) and now kW (KiloWatts) to rate the power of a (combustion/electric) engine. One PK = 736 Watt, that's 10 Watts short. Normally it should be the same...

Anybody know where the difference may come from?

-- Pros

-1982 Range Ruster V8-

(E-mail address is forged - reply to group please)

Volts time amps works with DC, or for AC in a resistive load.

Motors aren't a resistive load, and the voltage and current will be out of phase, which makes things complex.

I know just enough to know I don't know enough.

The difference is that there is a UK horsepower (hp) = 1.34102kW and a metric horsepower (HP) = 1.35962kW

Tony.

Many thanks Adrian - even if the news you bring is not what I wanted to hear at least i know!! There is indeed a speed of 1460rpm marked on the same plate....

So if anyone wants such a motor in part exchange for a bigger one, I know hwere there is one!!

David LLAMA 4x4

What are you trying to run?

A 3hp single phase motor, if you can find one, will be nearly the same size as a washing machine drum and at least as heavy.

Are you sure that's what you need?

Slightly smaller horses. Or lower octane grass.

In article , David French writes

That's a circular argument:

slightly smaller horses = less fertilizer = lower octane grass lower octane grass = slightly smaller horses

In article , Mr. Nice. writes

IIRC the hp was invented by Watt. He was having problems selling his steam engines because the mill owners couldn't understand how much power they generated. Watt decided to enumerate the power in a way they would be able to understand more simply and came up with 750W ish. As to which horse was used as the benchmark I've no idea, but probably not a Shire horse, which IIRC can easily exceed 1hp.

Twas Tue, 1 Jul 2003 23:41:34 +0100 when "David French" put finger to keyboard producing:

LMAO!

-- Regards. Mark.(AKA, Mr.Nice.) ___________________________________________________________ "To know the character of a man, give him anonymity" - Mr.Nice.

mr.niceATsofthome.nethttp://community.webshots.com/user/mrnice106___________________________________________________________

I have purchased a new ( to me ) lathe. Since moving into the wilds the biggest thing I miss is being able to nip into a friendly engineers and use their equipment for an hour or so.... we now have an 11 mile round trip to get to the fish and chip shop and back !!!!

The lathe is straight out of a factory toolroom and has a 3hp 3 phase motor fitted. The work I have for a lathe means I need the features of a big lathe ( hollow arbor, big swing over bed ) even though I am only doing lightish work ( facing, centre drilling, turning etc ).

I suppose I could get away with a 2hp motor as long as it will turn the lathe as I am not doing any of the heavy jobs ( screw cutting etc. ) that the original 3hp motor was able to power it to do.

David LLAMA 4x4

I suppose I could stuff finding a motor and tie a small horse to the flywheel of the lathe!! There must be a few welsh mountain ponies around here - even if there isn't I could borrow one of the big posh horses from the stud farm down the road...

David LLAMA 4x4

In article , David_LLAMA4x4 writes

Dave You wanna try getting three phase down south.

I have a 3phase cable that runs through the bottom of my field.

All I asked was that they put a pole in the ground and run a supply up the pole I was going to run the cable the 1/4 of a mile to the workshop.

The want 15k just to give me a three phase supply directly above the cable in the field !!!!!

My solution was to buy a 3phase genny Which will run the ramps and compressor in the workshop.

On or around Tue, 01 Jul 2003 22:04:56 +0100 (BST), snipped-for-privacy@zhochaka.demon.co.uk ("David G. Bell") enlightened us thusly:

eeek. don't go there. you'll end up with differential equations afore you know where you are. there are different kinds of motor, too - some are not good for high start-up torque. Generally, the ones that are will take a big initial current.

I have a 3HP one on a pressure washer, running on a 13A fuse. If you're reckless enough as to switch on without first pulling the gun trigger, instead of starting the motor it blows the fuse. If you once get it running, it's fine.

On or around Tue, 1 Jul 2003 23:41:34 +0100, "David French" enlightened us thusly:

there's a PS as well, which I speculated could stand for Pferde-Scheiße, but probably stands for something more boring, which might be the same.

proper BS horses are 746W, roughly.

dunno about them french steam-horses (CV = Cheval Vapeur).

Don't look, Nikki...

The problem with using horses from a stud farm is that there are power losses in the conversion of reciprocating motion to rotary.

(Nikki, I told you not to look!)