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Please Critique My VFD Installation/Protection Plan

Joined
Aug 6, 2017
Location
Tigard
Converting 460v 3 Phase Lathe with 5HP Baldor to 230v single phase for use in my garage, because, well, I need it. Powered from 50 Amp breaker through twist lock 4 conductor 30A cord. Same breaker connected to welder, but not used simultaneously. Swapped 12 gauge cord for 10, two of the fuses to 40A. Instead of getting 2 pole contactor, I thought I would just get the 3 phase 40A with overload running through all legs in case someone wants to run the lathe on 3 phase someday (after I'm dead or in an Alzheimer's facility). Forward and reverse lever on apron wired to low voltage control on VFD. Speed control pot also direct to VFD. Maybe wire a jog/inch button to make indicating fun. Power to contactor is 120v from one leg of the 240v line to neutral. Momentary contact power button energizes contactor and stop button interrupts latching. I think I want the foot brake to actuate the VFD braking mechanism as the lathe came with braking resistors!

VFD is Invertek, labeled for 30A but asking only for 40A fuses. It's the biggest one that could do 5HP single phase. I'm looking at amazon dot com/dp/B0080HEVH8 for the contactor/overload, because but I don't need no stinkin' weird paths to ground.
I'm a newbee, apparently, so can't post real links yet...

Edit: That coil seems to be 208-240 VAC, not 120v.

Thoughts on this made in Brazil WEG? Even Allen-Bradley is made in China now, but certainly to a standard. Thank you for sharing your knowledge! I'm really enjoying reading old posts, and I believe I have learned enough to make me pretty dangerous!

Oh, lathe is Taiwanese, circa 1992, weighs over a ton, built pretty well in the style of Clausing/Colchester. It might be one of those mil spec models, came from Boeing. It's a little tired, but I'm fixing it. It has never been loved so much, and I have the grease stains on my crotch to prove it!
 
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Instead of getting 2 pole contactor, I thought I would just get the 3 phase 40A with overload running through all legs in case someone wants to run the lathe on 3 phase someday.
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I'm looking at amazon dot com/dp/B0080HEVH8 for the contactor/overload, because but I don't need no stinkin' weird paths to ground.

Edit: That coil seems to be 208-240 VAC, not 120v.

It has never been loved so much, and I have the grease stains on my crotch to prove it!
There's something I hadn't considered about using the three phase contactor. I'm sure the contacts are only rated for 40 Amps combined, so I would need a much larger contactor for single phase. I really don't want to use a 240v coil, and that's all I can seem to find of the WEG.

Also, the fuses over 30A are no longer 13/16" diameter, but 1-1/16" so I had to order some new fuse clips— from Zoro on eBay. I hope I don't regret not paying eight bucks apiece to Amazon— Prime eligible! Wait, is that a double negative? No?

Oh, and the grease stains? It's from the scissor jack in the trunk. Honest.
I keep my arms in the legs of sweatpants in the trunk. Until I get a gun safe. To keep them away from my 16 year old son and his friends. Mostly his friends...

So, still looking for the right contactor with adjustable overload for now single phase 40 Amps, but these things are frickin' expensive! I just like the idea of power being completely off until I hit the green button, and then the green light goes on, and you know it's on.
 
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If I keep talking to myself, I'll eventually be off probation and be able to post links. So, in the guise of keeping you updated, I'm really talking to people in the future, in case they want to go back in time to bring me back to the future, which, of course they should, even if they don't know it.

I got my fuse clips quickly from Zoro. I would not hesitate to use them again. They will allow me to use Bussman JKS-40 fuses in my GE THC-31 fuse block / disconnect. My Invertec specifies fast blow fuses, so I chose the type J that would fit. I decided not to use the contactor to disconnect the VFD, but I did buy one. I have the disconnect on the back of the electrical panel, and I believe that will do for now.

I ripped out all the original wiring. It seemed overly complicated with three relays— apologies to Dennis Turk, if you were involved. The two switches connected to the apron mounted forward and reverse have been simplified to activate the VFD's run terminal and reverse terminal through one relay, along with the jog button, and is latched by the green start button, but interrupted by the stop button, the foot brake, and the gear cover interlock switch. I didn't think letting-up on the foot brake should
start things moving again without having to push the button again, but can easily be changed. It's amazing how many fewer wires there are.

Now, just need Amazon to send me an actual twist-lock outlet, instead of a mislabled plug, get my fuses in the mail (tomorrow), and acquire 10 gauge wire to connect my fuse block to the VFD. Really, 12 gauge for one foot is not sufficient?! I would have thought so, but, well, that website said it wasn't. I can't wait to get this thing going, because it's been too long!

It was kind-of cool doing this because now I know it inside out.
 
I'm sorry, I should have reported back. I got a new toy and forgot all about my old friends. So, I got it all wired and powered it on and... instant fault from the VFD. Damn, motor's bad I thought, but I checked the wiring on the motor and sure enough, I mistook a worn 8 for a six or nine, I forget which, fixed it and it worked perfectly. I was lucky that the Invertek VFD detected the fault and didn't destroy itself or the motor. Whew!

I decided not to use the twist lock connector because it was only rated for 30 amps, so I used the NEMA 14-50 outlet and put the same plug on the welder. It doesn't ever use that much current– the 30 amps is only on startup of the vfd, and it really wouldn't have time to overheat anything, ever, so, way overkill. I bought a jog button but didn't wire it. It's easy enough to turn by hand, it's a toy.

The Minarik tachometer (VT something) didn't work, displaying random garbage on power-up. I checked the power supply on the Fluke meter and it was within reason. Looked at it on the 'scope and way f**ked. I replaced the capacitor on the power supply and it was fixed. The plastic bezel of the Minarik was cracked or should I say disintegrated. It is in a Ziploc bag now, being saved for posterity, and replaced with a stainless single rocker switch plate (the screw holes line-up perfectly) and a red lens made from two layers of the transparent red lid material of a random serving-saver food storage container I found in the cupboard. The previous was inserted for anyone searching for how to fix the Minarik instead of paying two or three hundred dollars from the extortionists on eBay.

The three axis Acu-Rite DRO works great, but the Z-axis needed to be multiplied by 1.25 to be accurate. I wonder how long it had been like that?! Anyway, the lathe works very well, and thank you all for taking such a profound interest!
 








 
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