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Hello!
How would you normally drive a 220v servo in the USA?
240v is absolute max on the servo so 2x120v would not be adviced and most transformers seem to be 120 to 240v.
Is there also 120 to 220v transformer? link?
Whats the normal voltage in the US, is it 120v?
Thanks.
Normal single phase in NA is 120v / 240v, you have a choice of what you can use , most servos will be fine at plus 20% if you correctly wire the drive with the a reactor and power filter there should be not problems with the over voltageQuote:
Originally Posted by jeeybee
You never size the power supply to the exact plate voltage of the servo, any overcurrent or other limits are taken care of by the drive.
IOW, there is a controller between the motor and supply.
As a rule it is over-current that can damage a motor not over voltage, within reason.
Al.
Ok, on the drive it says 220v -15% +10%
So max for the drive should be 242v and according to wikipedia the US can have a fluctuation of the voltage of about 6% which would be max 254.4v.
If it was only for me I would have tried it but as I´m sending it from Sweden to a customer in the US I´m a bit more careful :)
Then get a drive that says 240v or even 230v they have them 220v is a Chinese labeling thingQuote:
Originally Posted by jeeybee
I have only ever seen 245v max in NA I doubt that it would ever get to 254v range that would not be good for most things
If this is a commercial sale etc, and you are concerned about selling to the N.A. market, you could do some definitive tests on a product before shipping, such as a maximum estimated Supply limit test using a Variac to take the voltage up to the estimated limit. l.;)Quote:
Originally Posted by jeeybee
Al.
Ok thanks, its hard to make long term stress tests though.
Quote:
Originally Posted by jeeybee
The other way to protect yourself is to offer a max Voltage, say it is 220v / 230v and the end user would have to use a Buck Transformer so it did not go above your max voltage Buck Transformers are not expensive for low amp application's
Buck / Boost Transformers are use when doing small changes in voltage supply: 5%, 6.6%, 10%, 13.3%, 20%, and 26.6%
Is it 220V/single phase or 220V/3phase?Quote:
Originally Posted by jeeybee
240V is fine for the 220V driver because there is tolerance, just choose the same phase is okay.
Typically the 1 phase voltage in N.A. is now 120/240v
Rarely seen is 220v 3ph, 208 3ph is more common.
Al.
I've spent several decades developing PSUs and VFDs and we always designed for 240 +10% ie 264V. The +10% is required (by UL, CSA etc) on top of the declared sticker voltage. And you wouldn't expect it to blow up at 265V - there are voltage transients to design for, caused by the effects of lightning strikes, fuse blowing spikes etc, which require some additional design margin above 264V.
The supply here in the UK is typically 240-250V these days and it doesn't cause a problem. I lived in Canada for 5 years and my UK stuff was fine on the 240V there. You shouldn't have a issue.
This is not what the problem is his servo drives are rated for 220v which is normal from China, and wants to find a way to run them safely on 240v / 245v PlusQuote:
Originally Posted by Muzzer