Looking for motor starters with adjustable thermals

[garbo]

I don't know where you get the idea IEC contactors are garbage. I have literally put tens of thousands of them in my designs over the years. I cannot recall having a single one fail in normal use. It is true that you cannot replace the contacts on them. But it is generally cheaper to replace an IEC contactor than it is to replace a contact on a NEMA starter. And usually much quicker to do so.

There are also a lot of nifty doodads you can get with them that make them a whole lot easier to use in groups.

And you cannot beat the space-saving.

It is also true that you have to think a little bit about what you're doing and maybe upsize them sometimes. But the vast majority of applications that's just not necessary.

Like anything I suppose there are differences in quality between different brands, and maybe you just got someone who misapplied them. I can't imagine why a bypass application for a VFD would ever fail since it will not close or open with a load on unless the VFD fails.

I did find some older Danfoss VLT model for drives with bypass had 30 HP IEC contactor on the M1 input contactor that feeds 40 HP drives . The M2 output & M3 bypass both were 40 HP drives. Tech that performed our start ups did not no about this. Both of the 30 & 40 HP made in Italy GE IEC contacors were both the exact same size. Tech thought that being the M1 input contactor always had a low in rush current especially on drives that had start ramp times above 10 seconds could get by with a smaller size. Anyway the M2 IEC garbage contactor went bad at least twenty times more often then the M1 input or seldom used M3 bypass contactor. Every time we did our monthly ATS testing in a large research building with older VFD'S with bypasses I had to replace at least one of the M2 garbage IEC contactors. Most of these drives ran 24/7 and all had long ramp up times so one would think.that a contactor that has only been shut off less then 200 times during its 6 to 8 year life would last a lot longer. All were in clean cool enviroment except for maybe 25 in a basement chiller & pump room whose temperature was in the high 80's summer months.

 

[norcal]

I have a much better opinion of IEC starters then I used to, had to replace the reversing contactors on a commercial washer, OEM was SQ D hoist contactors that had failed replacements were A-B IEC contactors, that washer is used for 2 shifts a day 7 days a week, every day of the year including holidays, & the wash cycle is programmed for a few mins. forward, short stop period, then a few mins reverse, then repeats, this goes on every wash cycle, after many years those contactors are still going strong even after being the machines being abused by low paid laundry aids, that is just one example but led me to change my view of them, I still prefer NEMA starters but not going to bad mouth name brand IEC products. Later versions of that make of machine use VFD's.

 

[Jraef]

Technically the input contactor ahead of a VFD need only be rated at the input current rating of the VFD, because it never has to start or stop the motor directly. So the load on that contactor is more like that of a lighting contactor, plus the input current of a VFD is lower than the rated output current of the VFD.

Still, kind of cheap-shirt if you ask me, I would have just used the same contactors all around, that way there is only one spare part. I mean, how much did they save between a 30HP and 40HP contactor, $10?

 

[petersonra]

Had to replace IEC contractors & starters sometimes twice a year especially on waste water pumps that should have had tanks many times larger to prevent pumps from setting & stopping 20 times a hour. Had to throw out expensive 75 & 100HP garbage IEC contractors that were not that old because you can not replace the contacts like the full size NEMA made in USA starters. Had trouble countless times with VFD drives with enclosed 2 or 3 contractors used for bypass. IEC contractors would often single phase or no pull any of the 480 volt contacts in even while measuring 115 to 122 Volts AC at coil after power was off to perform 1 to 4 times a year PM'S.We had a tech who worked on nothing but larger vacuum pumps and he had the same option concerning short lives of IEC contractors. Told me on most vacuum pump stations that had 2,3 or 4 IEC contractors he left a brand new replacement inside of cabinet to save time running to get one.

this sounds like someone misapplied them. one thing about iec contactors is there is not as much conservatism build into the basic unit. you have to look at the application to figure out what you actually need to buy. you cannot always just select by HP like you can a nema starter. but people do not understand this.

 

[Jraef]

this sounds like someone misapplied them. one thing about iec contactors is there is not as much conservatism build into the basic unit. you have to look at the application to figure out what you actually need to buy. you cannot always just select by HP like you can a nema starter. but people do not understand this.

That’s the crux of the problem. IEC contractor selection is supposed to be done as a process, (referred to as rationalization) involving the motor HP, duty cycle, power factor at the moment the motor turns off, expected mechanical and electrical lifespan, etc etc. NEMA selection is just by HP, then all the other issues are assumed to be the worst.

 

[garbo]

A NEMA size 1starter is actually rated for about 27A. An IEC contactor rated for the same current will exhibit similar performance, life, and physical size.
People often get into trouble using IEC devices when they are sized only by the nameplate HP.

Believe you are way off about IEC contractors & starters having same life as a real deal full size NEMA contactor or starter. Seemed to .years ago that a NEMA starter is good for 1 million operations while the garbage IEC was only good for 50,000 to 100,00 but today said both good for a million . Pure 100% lie. Like Silk posted recently had VFD'S with bypass that ran 24/7 year round. Only b time the POS M2 output drive contactor ever shut off was on monthly ATS testing . Had maybe 100 of bypass drives in this 12 story research on center. After every ATS testing would have to replace at least one of the POS IEC M2_output contactors. Always had between 117 to 122 volts to POS IEC contactor but coil would either inky pull in 1 or none if the three 480 volt contacts. So all of these POS IEC contactor went bad before 200 operations. Back in the 198)'s worked in a large candy plant where they had over 25 18' deep storage tanks loaded with chocolate that the energy management system had them run 15 minutes on 15 minutes off 24/7 all year long. Around 35,000 start stops a year using real deal A&B NEMA starters from the 1950's. Maybe once a year had to rep!ace a starter coil and never had to rep!ace contacts. Sure a a typical POS IEC starter would not last 2 years .

 

[jim dungar]

Believe you are way off about IEC contractors & starters having same life as a real deal full size NEMA contactor or starter.

IEC contactors have been properly applied for decades all across the world. Misapplications, particularly those associated with cutting costs, can occur with every product.