Inverter drives



David
If you don't have the basic Electrical knowledge to fit the inverter, set the parameters on the VFD (Inverters) and wire the controls with appropriate interlocks (or have someone who can to advise you), go the Newton-Tesla route. A little expensive but safe.
Gavin O or E-bay units are often older models of VFD and you may not be able to get the instructions allowing you to set it up (change the parameters). Previously owned usually means limited (sometimes no) gurantee. I don't think the prices are always low either. You need to gave a good "feel for the deal"
Drives-direct do some good "packages" and, judging by their adds in ME/ MEW, have "moved up on the supplier ladder". They certainly advertise assistance and control systems. Again, may not be as low priced as other routes - but you'll have "on-line help".
Finally, the RS route is a good bet - assuming you have the basic Electrical knowledge (or access to someone who does). Bear in mind that you'll need a gew more bits and - as RS supplies to the trade - you'll get lottle back-up and you'll need a "trade account" with them. Maplin don't sell VFDs.
Just remember, if you can blow a single-phase motor it's even easier to blow your 3-phase ditto and a VFD if you don't know what you're doing.
Regards Andy
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In article

Andy,
Thanks for these thoughts. I have no problem with single phase switch units and am also OK with 3 phase on paper (though no direct experience) - and I have a friend who is an ex-RN electrical engineering officer if I need any assistance. For me it's the time - pricing up the RS stuff with all the bits and bobs needed, plus VAT, and the difference starts to look fairly modest even before you reckon all the extra work involved. I'm sure if I was prepared to wait and spend time it could be done for half the cost, but there are other things I'd rather do.
And I do know what you mean about the instructions - I have a 3-phase/inverter on my T&C grinder, bought second-hand with no instructions, and I have no idea how to change anything. Fortunately it is not the sort of machine where I need to, so I have just let well alone.

The jury is still out on what happened - I hope to dismantle the motor assembly this weekend, tedious job as the lathe is hard against a wall and too heavy to move easily - but I'm pretty sure the motor is not burned out. It is locked solid, won't turn even a tiny fraction of a degree (and yes, the clutch etc. is all disengaged). I am wondering if something has got into the casing, or the centrifugal switch has fallen apart or something.
David
--
David Littlewood

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Bear in mind

No need for a 'trade account' with RS, I've been buying from them for many years without any kind of trade account (maybe I ought to open one !!). Brad.
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wrote:

Yep - anyone can buy from RS; the difference is that if you have a trade account, the postage is free (as long as you order via the web). Used to be a guaranteed next day delivery too...not quite that good nowadays but never taken more than 2 working days.
Regards, Tony
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