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1200 HP soft start

1.8K views 14 replies 8 participants last post by  micromind  
#1 ·
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Retrofit. The original had problems like taking a dunk a couple times. The firing boards were no longer repairable (too old to get parts). The old firing boards were in the controls instead of the current design that runs plastic fiber to the control board. The phase stacks and half the CTs and controls (not shown) are all new. The contactors and PTs are original, I tried to clean up as much of the customer wiring as possible. Not a fan of the power wire routing but that’s factory original and seems to be holding up with no signs of corona damage and I was on a time limit getting this thing operational.
 
#3 ·
Once upon a rosy day there was a company in Florida that rebuilt boards. We used them decades ago for the old McQuay drives and some of the old Toshiba drives.
Sorry I do not remember the name, probably changed any way.

I have worked on the newer Eaton models and prefer the products from Toshiba.
Living where it is hot 2/3's of the time it is handy not to have to pull a circuit out to the middle of no where land for an air conditioner. Ya the Toshibas can handle Arizona in the summer with out anything other than the factory cooling. My experience is mining applications
 
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#4 ·
Once upon a rosy day there was a company in Florida that rebuilt boards. We used them decades ago for the old McQuay drives and some of the old Toshiba drives.
Sorry I do not remember the name, probably changed any way.

I have worked on the newer Eaton models and prefer the products from Toshiba.
Living where it is hot 2/3's of the time it is handy not to have to pull a circuit out to the middle of no where land for an air conditioner. Ya the Toshibas can handle Arizona in the summer with out anything other than the factory cooling. My experience is mining applications
As far as soft starters there were 4 domestics: SAFtronics, Phasetronics, Benshaw, and Toshiba (Houston). This is soft starts, not VFDs. Since then SAFtronics has disappeared in all but name only. I haven’t seen a Toshiba in years. That leaves Benshaw and Motortronics/Phasetronics in MV. Both are pretty similar products but the Benshaws have better customer support. Again this is MV Soft Starts.

In MV VFDs there is a larger field. The thing to remember is that there are only 3 manufacturers of the actual modules in use. Unlike LV the cable surge rating is not very high so you MUST use multilevel drives or lots of filters. There is no “5 kV IGBT” last I looked and HV IGBTs are very overpriced. So the first designs were often LCIs but that has mostly gone by the way side. Current designs either eat the higher cost of the HV IGBTs and use a neutral point clamped design or use a more complicated transformer and cheap low voltage IGBTs in a cascaded H bridge design,

Toshiba was the first one with a really solid MV VFD and still has a big name. The thing I hate about their drives is that all the mass of the sections is at the top and weighs a couple hundred points. On a flat, level surface it’s fine but on a mining skid changing parts is a nightmare.

I didn’t even know Eaton had a MV VFD or soft start. Their LV soft starts have one feature: tiny. That’s also the problem…they overheat and fail pretty often. WEG has patterned theirs after Eaton as well but nobody else is following their lead. I have worked in Eaton switchgear and starters in mining. I was not impressed at all. It looks nice until you try to work on it.
 
#5 ·
Eaton bought their MV VFD and soft start from some proprietary company that does mining on the eastern part of the country. The current tech soft and vfd's come from the boys that jumped ship from ABB. They were in Europe and then wandered over to Canada. When the SV9000 was introduced to us in the states it did not have a UL label. Did not sell well. Did not preform well in dirty or hot applications. I got my first 400 hp Eaton soft start for a water pumping application, primary water for the chillers. The instructions said 40C. I called them up and asked if they were serious. Of course the guys that designed the product were from Canada and Pittsburgh. Arizona was not what they were thinking about. I explained it got hotter than 40c inside the plant when the equipment was running. A bit of a stretch but not that much.
Summers the new 400 hp softstart did not do well. To hot. So being tired of dealing with it we ducted 8" of airconditioning into the top of the cabinet and reversed all of the fans to blow down. Never had a problem after that. Eaton did raise the temp up to 50C after a time. Kept the softstart cleaner as well. Adopted the pratice in many equipment rooms.
 
#11 ·
The old one was a Benshaw Micro. The new one is the Benshaw MVRXE. If you are familiar with the product the big changes other than newer parts is that the phase stacks communicate with fiber instead of electrical wiring which is very common among all MV brands these days. The main board is essentially a modified MX3. Much more compact. They supplied it with the entire control panel and the entire phase stacks prebuilt with some extra long glastic strips so that the phase stacks bolted to the original studs. We didn’t have to drill a single new hole for anything. Everything came in a big kit. It came with prewired cabling, fiber, plenty of cable loom. The only thing we supplied other than labor was a lot of tie wraps. The instructions were the standard manuals and two sets of prints, the final one and one with a lot of “cloud” markings showing most of the changes. There were a lot of controls changes. The MVRXE and Micro are twenty years apart. Much of the controls was simply completely different. But at the end of the day after adjusting some programming on the relays and replacing one bad cable (our fault) it just worked exactly like the original.

I do recall now dealing with a single Toshiba MV soft starter. It was a private labeled Motortronics but in a very unique and frankly terrible layout. All contactors were Toshiba which is fine. But it had the controls in the middle of the cabinet and at least one contactor including the incoming wiring was buried in an inaccessible area behind it. It was decently built but extremely maintenance unfriendly. When the firing cards developed an issue Toshiba played clueless and Motortronics was pretty much avoiding it like the plague. We ended up tearing out the whole thing and replacing it because it kept blowing out the utility fuses on the primary side of their transformer and was turning into a money pit. We were stuck replacing all 3 phase stacks at which point the water plant just wanted to replace it all with something reliable.
 
#13 ·
Motortronics brand labels their MV soft starter to Toshiba, ABB, GE (now ABB anyway), Siemens, Square D, Eaton and a couple of European companies that don’t sell here. Some of them like Eaton and Square D incorporate the guts into their own switchgear packages, but the rest just buy the whole thing from Motortronics. The Toshiba LV soft starters are also brand labeled Motortronics, and ABB used to before copying it and making it themselves. When I worked at Motortronics, I used to joke with the owner that he should hang a red light above his office door so that the rest of the sales force would know when he was whoring himself out again.

The only other North American manufacturers of MV soft starters left are now Benshaw and Allen Bradley. There used to be a New Zealand company called Aucom assembling MV soft starters and selling them here, but Benshaw bought them a few years ago and merged the product lines.

There is an Israeli company called Solcon that still sells here, and Weg sells an MV soft starter, but both of those are made overseas and not supported well here. I’ve seen a few Chinese suppliers trying to get in the game here but I wouldn’t touch those with a 20ft hot stick…
 
#14 ·
How times have changed. I used to sell both Eaton and Toshiba MV starters for the mines near here. Our techs had been to Houston and had the week long MV starter school. So most of the small stuff could be handled by us. I never cared for the Eaton MV Soft-starts as some of the parts (that went away in the heat) were hard to get to. The Toshiba cabinets I sold had cooling fins on the back and could literately be set in the Arizona sun and have no problems. Every one else we had to put in a room with AC. Some of the AC's were pretty big, like 30-40 tons of cooling. A lot of heat coming off the MV stuff.

Nothing wrong with Motortronics, in fact sometime they were less expensive for the same product.

All that was close to 20 years ago now. Glad I do not have to deal with MV any more.