By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

Chipmaster motor wiring

All Topics | Latest Posts

Search for:  in Thread Title in  
Les Jones 127/08/2021 15:56:41
2292 forum posts
159 photos

It is not recommended to do any switching on the output of most VFDs. I suggest that you check with the manual for the VFD that you have. You normally have the forward ,reverse and stop controls together with the speed control potentiometer mounted in a convenient position away from the VFD. The wiring between the controls and the VFD is only low voltage and current so thin multicore wire is used. It is probably possible use the old forward/reverse/stop controls connected to the control inputs of the VFD. using the old controls in this way may give problems as sometimes the contacts oxidise when there is no cleaning action that occurs when switching high voltages.

Les.

John Haine27/08/2021 16:52:21
5563 forum posts
322 photos

If you forget and open the switch between VFD and motor while running it can generate an inductive spike that destroys the output transistors. Much better to make a direct connection and do the switching and control on the control side of the VFD. For one thing you can usually set the VFD for a controlled accelerate/decelerate time - no need for a clutch.

It won't be so relevant on a lathe, but on a mill for tapping it's convenient to have the motor set for running slowly (say 10 Hz with a large belt reduction), then bring the tap down so it's just resting on the top of the hole, switch on in forward, run the tap to the desired depth then just switch from fwd to reverse. The VFD will happily bring the motor to a controlled stop then reverse with no drama. Try doing that with a normal reversing switch on the VFD output and it would definitely object!

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate