VFD milling question

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Despite the fact that the most common definition of an inverter seems to be: "an apparatus which converts direct current into alternating current"

I fear this may not be sufficiently explicit to satisfy Mr. Stevens

MichaelG.

Hi Michael

Searching VFD on the linked page provides 32 choices, not much help to the uninformed as there are more than one with electrical bias.

Emgee

Nevermind the simple, most used option of using "G-oo-gle", a search for vfd in the search box for the forum immediately gives a pretty good indication/description a very short time after clicking on the "GO" tab! If someone goes looking for every possible meaning amongst dozens of acronym meanings should learn the KISS principle!

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Emgee,

Yes, I am perfectly aware of that ...

Please understand that my post was a specific response to a specific statement by Mr Stevens.

MichaelG.

IMHO It's good for people to have to think and do some legwork, I think we should all try to use, TLAs, acronyms and abbreviations wherever possible

HTH

Nick

Sorry if I'm missing something but do you really need more than a 2.2 kW inverter to run a 2.2 kW motor? As far as I'm aware and in my experience, reasonably modern inverters will do what they say on the tin - no need to over-rate. Might be worth trying the 2.2 kW one on some 'real work' - I'd be surprised if it wasn't perfectly adequate.

There's also a much wider choice of single phase input VFDs in <= 2.2 kW than there is in higher power ratings.

I thought that it was the peasants who were revolting.

Or did I mistakenly spell that with "as" instead of a "d"?

Howard

I'm sure your probably right Pete, but as I had to buy one anyway, I thought there was no harm in having a bit of headroom. Especially as I've gone for a cheapo chinese jobbie, £130 delivered for a 4kw inverter.

i paid more than that for the 2.2 kw one, which was secondhand, although it is a good name brand.

An inverter is not necessarily a Variable Frequency Drive (VFD). I was taught that is was only allowed to use abbreviations after the term had been used in full in an essay. Many technical books will have a glossary to expand on any abbreviation used. The inverter is only the output stage of a VFD. The AC is first rectified to provide a high voltage DC stage usually called the DC link then it is switched to give three phases at the desired frequency this is the inverter part usually implemented these days with Insulated Gate Bipolar Transistors (IGBT)

Mike

Indeed, you'd struggle to run a 3-phase motor with one of these inverters.

Alan - if you are going to spend that sort of money you might as well buy a proper one. It will do a genuine 2.2kW without breaking into a sweat and won't pop when you try to use it. Why have cotton (or a pig's ear) when you can have silk?

Murray

Edited By Alan Waddington 2 on 07/12/2016 21:49:41

Oops, sorry about that. Being a Scottish-blooded Yorkshireman, I understand how this can cause a significant loss of sleep!

Note that the model I linked to is the J1000 series which operates in simple "constant VF" mode, whereas the V1000 models use sensorless vector control ie a bit more sophisticated. Worth the extra £20 in my mind but depends if you are working to a budget.

The V1000 technical documentation gives you an idea of the capabilities of these industrial drives.Pretty impressive stuff.

Murray

Yup V1000 4kw £191...... **LINK**.......would have definitely stumped up the extra £60 to get that

Note that the Inverter Supermarket prices don't include VAT (20%) or shipping (about a tenner IIRC). So £191 turns into more like £240 delivered...