3 phase electric HELP

[cqueen]

I have bought a piece of machinery that runs on 3 phase. In true PH style I thought - 'Simple I'll just buy a converter'. Now bearing in mind I don't even know what 3 phase is/does - I need some help.

So to help figure out what I need, the machine has 4 motors each rated at 0.37Kw.

Convert Kw to HP =

0.37Kw x 4 motors = 1.48Kw (x) 1.34 = 1.98hp

Now that's just the power to the motors, what about the little light bulb and electrics for the switches/digital displays?

Would a 2hp static converter be ok? Are static converters silent (or at least quiet)?

Thanks

[cqueen]

Blakeatron said:

I got it wrong and it hurt

Physically or financially?

[cqueen]

hidetheelephants said:

There are a variety of ways of running 3 phase machines;

1. Using 3 phase leccy direct if it's available; commercial premises often have it, residential tend not to.
2. Rotary converter; noisy and inefficient.
3. Static coverter; expensive for what it is and bulky.
4. VFD inverter; whizz bang electronic wizardry, you can vary the motor speed and all sorts.

Machine Mart flog rotary and static converters and there are a number of online dealers who specialise in phase converters for domestic use of 3 phase machines. There are VFDs on ebay but you need to know what you're doing if it doesn't come as a turn-key non-electrician friendly package.

what's the machine? 4 half horse motors sounds like some kind of deviant woodworking multitasking wonder device.

So in short, you would recommend going for the static converter? bulkiness isn't a problem, the ones in machine mart are approx 25cm cube. It's a coffee roaster

[cqueen]

Well it's too late now - I've bought the bloomin thing!

Besides, if it's as easy as just plugging it in and away you go... what could possibly go wrong?!

[cqueen]

To be fair - I aint gonna go touching any wires. I'm just gonna plug the thing into a converter and hope it doesn't blow up!

The heating part is done by gas.

[cqueen]

skilly1 said:

Any chance Of a picture? I am intrigued by a coffee roaster that needs 3 phase!

http://www.youtube.com/watch?v=2EjLNSxk_7U

[cqueen]

Smiler. said:

Are you sure that these are 3-phase? What model have you bought?

Yes I'm sure. You can choose to have them built for single or 3 phase.

Not sure what the issue is though, There's only one plug for the machine and i'll stick it into a 2hp static converter. job done surely?

[cqueen]

Smiler. said:

Er, good luck with that then.

Well I havnt heard any reason why it wouldnt work? This is a used machine, I would have chosen single phase otherwise.

[cqueen]

mph1977 said:

the easy way to answer the question ifs for the OP to take a picure and show us

1. the rating plate

2. the plug on the end of it;s leads or the wires in the lead ...

Your wish is my command, also included the one of the motor plates..


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[cqueen]

Interesting, but do you think it would be worth the cost of a sparks time and any re-wiring costs? remembering that a converter will cost about £350?

[cqueen]

jason s4 said:

I recently installed something very similar and was able to wire it to a 16A single phase supply.

Can you give me a little more info on what you had to do?
Thanks

[cqueen]

I have no intention of touching this myself, i just wondered how much work would be involved for the sparky.

[cqueen]

thinfourth2 said:

P.s. I did all the 3phase wiring myself just to annoy the daily wail readers.

love it

Think I'll just buy a 3.5hp converter and see what happens.

[cqueen]

thinfourth2 said:

It will go bang or not work

Read what i said about control circuits

Also if there is a control box which will be a box full of controls.

normally identified by being box shaped and a removable cover.

Remove the cover and look for pieces of paperwork as the old fashioned way of doing things was to stuff a wiring diagram in there. If no paperwork or diagrams then take a picy of the bits inside

Edited by thinfourth2 on Monday 12th September 10:55

Why would it go bang? Yes there is a control panel and some paper diagrams, but im not at home right now so will post them later. Thanks

[cqueen]

thinfourth2 said:

Answer the question about are the motors individually switched as it is important.!

Yes the motors are separately controlled. Most of the time only 2 of them will be in use, sometimes all 4

[cqueen]

So why would this be different to a lathe or big saw in someones domestic workshop? Can't i just buy a converter that is powerful enough to cope?

[cqueen]

I stopped by an electrical supplier/contractor earlier, he recommended a local company that would re-wire all the motors for probably less than the cost of the converter. I'll pop down there later and see what they say. Sounds good though!

[cqueen]

Hmmm I've just spoken to a couple of electrical motor engineer types, the both said 'mmmmeh, you'd be better off just buying a converter'. Although I kinda got the impression they just weren't really interested in the work.

[cqueen]

some more photos...



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[cqueen]

Any good?



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