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Thread: New DOL or VSD?
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1st January 2018, 05:14 PM #1
New DOL or VSD?
Hi all, it's been a while, but I'm finally getting around to cleaning up the Jeffwood 702 panel planer (thicknesser) I picked up about 2yrs ago. I've got some specific Qs about the Jeffwood, but I'll post them in a pre-existing Jeffwood thread to keep them together. This question is more of a general power question related to an antique motor, so i figured I'd post it separately here.
While everything seems to work fine, the plastic housing for the DOL motor starter has been damaged in transport - and is now cracked and loose. So I figure while I'm refreshing the rest, I may as well replace it. I have no idea of the history of the machine, but I presume (rightly or wrongly) that the original DOL is the correct size - so, first question, is it? And the follow up, if not, what is and why?
IMG_0686.jpg
So, second question: I'm assuming the easiest option is to replace the DOL, but is swapping over to a VFD (3ph-to-3ph) an option for soft start motor control?
Preface all these questions with the fact that I have 3phase power in my shed, so no need to convert to 240v and as an aside, the motor on the Jeffwood appears to be a c.1950s Crompton Parkinson 3-phase 'heavy as all get out' thumping big lump of a thing which seems to run just fine. Specs (I think - the motor plate is quite worn):
Delta wired - marked as 'mesh'
1420rpm
2.75hp
4.5A
400/440V
50Hz
IMG_0687.jpg
Your thoughts would be appreciated - with all the usual disclosures and warnings accepted regarding electrical advice provided by forum members
Cheers
LeanneI think, therefore I am... unable to get anything finished!
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1st January 2018, 05:48 PM #2Woodworking mechanic
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Going by the motor specs, the DOL seems correct. 2.75hp = 2.05kW and 4.5A X 415V = 1.87kW
Clipsal - 56DOL16/1 - DOL Motor Starter, 7.5kW, 415V, 2 Push Button
As to whether a VFD would be an advantage, I’m not up on 415-to-415 connections so i’ll leave that to those more qualified.
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1st January 2018, 06:12 PM #3.
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You could just replace the plastic DOL housing with an IP rated box - that would be by far your cheapest option.
Given you have 3P I'm not sure why you would bother with a VFD as there is no need for speed control.
As you say the motor is a great big thumping thing so soft start does not seem necessary either.
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1st January 2018, 09:31 PM #4GOLD MEMBER
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Leanne, the only bit I would warn you about is if it's that old it may have rubber wiring going into the motor and that is a big fire risk.
Rgds,
Crocy.
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1st January 2018, 09:44 PM #5
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2nd January 2018, 11:30 AM #6Woodworking mechanic
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I have no experience with 415v but they certainly match the specs. Send NCArcher a PM - he’s the expert always seems happy to answer questions
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2nd January 2018, 12:57 PM #7
Hi Leanne,
You dont need a DOL starter that big. The motor is only 2kw. Get a 2.5 kw starter and it will have the correct size/range TOL in. I am interstate atm but will link to a correct one when i get back tomorrow.Those were the droids I was looking for.
https://autoblastgates.com.au
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2nd January 2018, 03:34 PM #8
Thanks Tony, that would be great
LI think, therefore I am... unable to get anything finished!
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3rd January 2018, 07:20 PM #9
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3rd January 2018, 07:29 PM #10
Be careful of the quality/commercial grade ones. They often don't come with a TOL. Can add up to $150 extra depending on the size required.
If anyone ever recovers a starter from a dead machine, don't throw them out. Will come in handy one day. A commercial and industrial sparky I was working for years ago had a huge pile of them and they saved us on many occasions.Those were the droids I was looking for.
https://autoblastgates.com.au
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3rd January 2018, 09:45 PM #11
As you've already got 3-phase power, and as it's for a thicknesser, probably the only advantage of a VFD is the soft start/braking. I'd say it's not worth the cost for almost no advantage.
I don't know Jeffwood machinery, but if it has a separate motor for the feed, then the ability to slow or increase the feed rate with a VFD could be very useful.
My tuppence worth.
Cheers, Vann.Gatherer of rustyplanestools...
Proud member of the Wadkin Blockhead Club .