There are two issues here. RF getting back to the vfd electronics, and the
actual motor speed compared to the supposed speed.
Firstly the RF may well blow the vfd unit unless you're very careful, but
there's been posts on that before.
Second, the speed of 1800 rpm is the assumed speed. In reality a synchronous
motor that is truly in sync with the mains frequency, will run at a speed
that varies a bit either side of 1800 rpm. This is because the mains
frequency varies slightly a bit as well. I have measured this myself with an
accurate electronic counter, giving 2998 rpm on a 3000rpm motor (freq =
49.97 Hz)
Being a few rpm out will result in the output slowly varying, as it comes in
and out of sync with the mains voltage peaks. How much is tolerable is your
choice I suppose.
To make it work you would need the impractical solution of monitoring the
mains freq to a couple of decimal places, then do the maths to get the
applicable motor speed, and then to match the vfd speed with the
calculations result.
Good Luck (especially with the RF issue)!
Regards
Phil Tuck
www.hvtesla.com
-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of David Boyle
Sent: 22 April 2014 18:51
To: tesla@xxxxxxxxxx
Subject: [TCML] srsg with a vfd
I have a chance to get a motor and vfd drive for a nice price for my
srsg. My only concern is would a 3 phase synchronous motor powered by a
variable frequency drive running at 1800rpm be in sync with the line
voltage?
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla