chinese drive voltage compatability

[dix2111]

Hi everyone,

I have a question about Chinese made "no-name inverter drives"

From what I hear they have a bad reputation for failing under heavy use and that they often only last a year or two at best (for 5 hp and above anyhow)

I have been looking into this because I plan on importing some 10 and 30 hp drives.

Could it be a problem of voltage. Most of the drives I have researched are made for the non-usa market. Mostly Europe, India and the middle east.

Most countries (for 3 phase ) us a 380 - 400 volt system that can withstand spikes of up to 460.

As you know , in the US we us 460/480 volt 3 phase service.

I'm not a technical person but I have a lot of experiance with the chinese market.
If a product will explode in a firey ball of flames at 461 volts they will rate it at 460 volts.

What voltage requirments should I require when purchasing these drives.
I was told (by a chinese salesman) that a 380-460 volt drive will work on a 460-480 volt system if I change some parametes but I am sceptical. Can anyone please help me out here?

[Al_The_Man]

As a rule, the 3 ph input to a VFD is to a 3 phase rectifier and then a capacitor bank, Most manuf. would fit these components with a satisfactory margin, instead of sizing to exact voltage input.
On the question of motor voltage, this is usually set by parameter to the information off the motor label.
Ask him what parameters are specific to the voltage change.
If the R.O.C. VFD's are anything like their motors, I would be leery of buying a quantity.
Al.

[dix2111]

Thanks for the quick response.

I am waiting for some more information from the vender.

In a previous email he said that it should handle the occasional voltage spike of up to 470 volts. If this is true it seems that this drive is probably made for a 400 volt system and would eventually fail under a 460/480 volt sytem.

If I require the drive to be made for up to 600 volts would that give me a adequate safety net.

Does it work that way?

I friend of mine works for a brokerage house and they import a lot of components from China to be assembled into vfd's in America.

Some of the largest drive manufactorers imports a lot of their parts from China so I know they can make good parts but why can't they put them together right?

[Al_The_Man]

If you get them rated for 600v 3ph then that should take care of the tolerance issue.
Besides you could then also sell the equipment in Canada
Al.