Need help with phase converter and switch

[Bobby Robbinett]

A few years ago, I bought a Torrit 5hp 3phase dust collector that didn't come with a starter or switches, so I built my own.
It's not particularly difficult to do, and cost me about $100 in parts from ebay.
It's an extremely high quality switch, but it does take some effort to figure things out and put it all together.

I used an ABB AF30-30-00-13 contactor mated to an ABB EF 19 electronic overload relay with a couple of Allen Bradley 800T momentary switches.
Your 7.5 hp motor would however require a larger overload relay, ABB EF45-30.

Having said all that, it sounds like you'd prefer a much more straightforward approach, and to that end I'd recommend a simple magnetic starter like this one from WEG. Only $99 with free shipping in the US.....

https://www.mrosupply.com/electrical...v24ax-r33_weg/

That gets you a starter with switches, but you still have to wire the static phase converter in there. That's where the manual or the schematics for the static phase converter come into play.

Here's what I cobbled together...

Thanks for the help Gustav! I will order one of those WEG magnetic starters with the switch built in as soon as I get paid this Friday. Got to hide any more purchases from the wife so she doesn’t get mad. LoL. I am sure that between myself and my friend we can figure out wiring it up. I have a family member down the road that has a large shop with a lot of three phase machines running off a large RPC and he bought a large dust collector with a 10 horse motor. He is wiring it direct where it will come on when the breaker in the main panel is flipped. He is setting this up to be his whole shop dust collector. He bought it used and said it didn’t come with a switch or a starter. Is this foolish of him? He says it’s fine to have it hard wired without a starter or switch but I told him I would ask you boys here and make sure.

[Rod Sheridan]

I wouldn't run a 10 HP motor without a starter with overload protection..........Where I live code requires it.

What does your local electrical code require?

Regards, Rod.

[Malcolm McLeod]

I wouldn't run a 10 HP motor without a starter with overload protection..........Where I live code requires it.

What does your local electrical code require?

Regards, Rod.

^ +1

But even ignoring code (but don't!!), a CB just isn't designed to routinely switch loads. He'll be buying replacement CBs in bulk.

[Gustav Gabor]

As I'm not a licensed electrician, please take my advice as only being from a cabinet maker who's done a good bit of electrical work.

Unless he is certain that his motor is thermally protected internally, I would most definitely not just use the breaker as the starter/on-off switch.
While it can technically work, breakers are just not designed for that purpose. WEG makes a 10 hp version of that magnetic starter for virtually the same money.

https://www.mrosupply.com/electrical...v24ax-r34_weg/

I'd strongly recommend doing it right. A 10 hp 3 phase motor draws a decent amount of current.
Also, be sure to use the correct size wiring and breaker.

[Bobby Robbinett]

As I'm not a licensed electrician, please take my advice as only being from a cabinet maker who's done a good bit of electrical work.

Unless he is certain that his motor is thermally protected internally, I would most definitely not just use the breaker as the starter/on-off switch.
While it can technically work, breakers are just not designed for that purpose. WEG makes a 10 hp version of that magnetic starter for virtually the same money.

https://www.mrosupply.com/electrical...v24ax-r34_weg/

I'd strongly recommend doing it right. A 10 hp 3 phase motor draws a decent amount of current.
Also, be sure to use the correct size wiring and breaker.

Again, thanks for the replay from Rob, Malcolm and Gus. I spoke with my family member about your advice on not running his 10hp machine on just the main breaker. I showed him the link that Gus posted and he agreed that for around a $100 he would be better to do it this way. He is supposed to order it today. He was under the impression that it would be a lot more expensive.

[Rollie Meyers]

I wouldn't run a 10 HP motor without a starter with overload protection..........Where I live code requires it.

What does your local electrical code require?

Regards, Rod.

Anywhere the NEC is adopted will require overload protection for any motor greater then 1 HP.

[Bobby Robbinett]

A few years ago, I bought a Torrit 5hp 3phase dust collector that didn't come with a starter or switches, so I built my own.
It's not particularly difficult to do, and cost me about $100 in parts from ebay.
It's an extremely high quality switch, but it does take some effort to figure things out and put it all together.

I used an ABB AF30-30-00-13 contactor mated to an ABB EF 19 electronic overload relay with a couple of Allen Bradley 800T momentary switches.
Your 7.5 hp motor would however require a larger overload relay, ABB EF45-30.

Having said all that, it sounds like you'd prefer a much more straightforward approach, and to that end I'd recommend a simple magnetic starter like this one from WEG. Only $99 with free shipping in the US.....

https://www.mrosupply.com/electrical...v24ax-r33_weg/

That gets you a starter with switches, but you still have to wire the static phase converter in there. That's where the manual or the schematics for the static phase converter come into play.

Here's what I cobbled together...

Getting ready to order this Weg 7.5hp magnetic starter and the link that you posted says this product is obsolete. Do you know the model I would need for a 7.5hp unit like the one in the link that is the new model or current version available? I need it to be capable of starting and stoping my PM72 3 phase 220v saw. Might also need a 5HP Weg magnetic starter for the 3 phase PM26 shaper that I got with this saw.

[Frank Pratt]

After reading the questions being asked here, it is obvious that a professional needs to be involved here.

[Gustav Gabor]

Not sure why it's obsolete now, as it wasn't at the time of posting it.

Try this one ..... it also has a 230v coil......so far it doesn't say anything about it being obsolete.......
https://www.mrosupply.com/electrical...v24ex-r33_weg/

These starters are available in various configurations, such as 120v coils and other HP ratings from MRO, just look through the listings under magnetic starters.
If at all concerned or unsure, please do consult with your electrician friend before proceeding.....

[Stephen Bandirola]

You are doing this the hard way.
Go to ebay type in 7.5 vfd $197.

add any old power switch like https://www.homedepot.com/p/POWERTEC...dalType=drawer

No starter or overload protection needed they are already built in.

I have been using 2 of the 5hp ebay vfd's (5hp table saw and 5hp dust collector) for over a year with absolutely no problems.

[Gustav Gabor]

I think you're missing the point.
He already has a static phase converter that would work for the saw in question. The saw just doesn't have an off switch or overload protection, thus the magnetic starter to work with the proposed static phase converter.

By the way, a 7.5hp VFD will not work on a 7.5hp 3 phase motor when it's being run from a single phase source.
It would need to be a 15hp VFD to convert from single phase to 3 phase, and those are most certainly not $197!

[Bobby Robbinett]

Not sure why it's obsolete now, as it wasn't at the time of posting it.

Try this one ..... it also has a 230v coil......so far it doesn't say anything about it being obsolete.......
https://www.mrosupply.com/electrical...v24ex-r33_weg/

These starters are available in various configurations, such as 120v coils and other HP ratings from MRO, just look through the listings under magnetic starters.
If at all concerned or unsure, please do consult with your electrician friend before proceeding.....

Thanks again Gus. I tried placing my order with MRO for this Weg magnetic starter but got an email yesterday saying that it was out of stock and would be a 3 month wait. Trying to find another supplier that is around the same price. Most other suppliers are in the $140-$160 range. I actually need to order three in total, one for a 10HP machine, one for a 7.5hp machine and one for a 5HP machine. Got my electrician buddy coming down a week from today so hopefully I can find someone stocked and able to ship ASAP.

[Tom Bain]

Bobby — I recently ordered a WEG starter from www.motorsandcontrol.com and it shipped out the same day. I will say that the PESW model numbers are vast and can be confusing so double check that you are ordering the right model.

[Gustav Gabor]

Thanks again Gus. I tried placing my order with MRO for this Weg magnetic starter but got an email yesterday saying that it was out of stock and would be a 3 month wait. Trying to find another supplier that is around the same price. Most other suppliers are in the $140-$160 range. I actually need to order three in total, one for a 10HP machine, one for a 7.5hp machine and one for a 5HP machine. Got my electrician buddy coming down a week from today so hopefully I can find someone stocked and able to ship ASAP.

After looking at their ad a little more carefully, under "notes" it states they only stock starters with 120v coils. .....isn't that just special!!.......
Having said that, it could likely be made to work with a 120V coil, but that is something you'd want to discuss with your electrician.

As Tom pointed out motorsandcontrol.com has WEG starters, and supposedly have 40 of these 7.5hp units in stock, but they don't have free shipping and are $20 more.

https://motorsandcontrol.com/weg-ele...losed-starter/ This is the 7.5hp starter $112.05

https://motorsandcontrol.com/weg-ele...losed-starter/ 5hp starter $99.27

https://motorsandcontrol.com/catalog.../category/168/ 10hp starter $141.74


They also have starters with metallic enclosures, but of course for a bit more money. For example a 7.5hp starter with metallic enclosure.....

https://motorsandcontrol.com/weg-ele...motor-starter/

[Stephen Bandirola]

I think you're missing the point.
He already has a static phase converter that would work for the saw in question. The saw just doesn't have an off switch or overload protection, thus the magnetic starter to work with the proposed static phase converter.

By the way, a 7.5hp VFD will not work on a 7.5hp 3 phase motor when it's being run from a single phase source.
It would need to be a 15hp VFD to convert from single phase to 3 phase, and those are most certainly not $197!

You might want to research modern VFDs before giving advice on them.