×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Homemade auxiliary power for elevator

Homemade auxiliary power for elevator

Homemade auxiliary power for elevator

(OP)
Hi everyone. I am new here and I would like to ask for your help about my small elevator.
So when the power is out I want the system to automatically switch to the power auxiliary system.So the only thing I came up with is the attached schematic but I fear the interference of the 220v of the ac outlet with the 220v of the inverter output.If you have any suggestions it would be appreciated. Thank you

RE: Homemade auxiliary power for elevator

You cannot do that for so many reasons...

Look up "automatic transfer switch".

Learn about the current needed at 12V to run your inverter.

Learn what "contactors" do.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Homemade auxiliary power for elevator

Everything Keith said - with a few questions to get you thinking:

You've gone to significant lengths to provide a 12V dc supply to operate a relay that's switching 12V dc. Did you know that you can get relays where the coil operates with a different sort of supply to the current it's switching? You can get relays with coils that operate off 230V ac - and most contactors use a mains voltage coil.

How happy are you with a system where the inverter backfeeds the supply line (and all its attached loads all the way back to the thing that tripped to cause the power cut)?

Get a highlighter and on your diagram mark the Live that comes out the inverter, trace it up to the transformer, across the rectifier and into the relay. Why is this energy path significant?

What does the spec sheet for your inverter have to say about having an external ac power source parallelled with the output? Does this change depending on whether the dc input is energised? How did Keith acquire his nickname?

You haven't drawn the motor controls. Did you just leave them out to simplify the sketch (fair enough), or are they in the power lines upstream of the drawing?

Does it matter if the elevator loses power? If it does matter, what are you going to do to make sure that the user does the right thing with the time the backup buys them, rather than getting caught out when the battery is exhausted?

A.

RE: Homemade auxiliary power for elevator

RTFM. Connecting AC to the output of the inverter will blow it up. It likely warns against that exact connection in the manual.

Even if it can provide the power required to run the motor, the inverter likely can't provide the power required to start the motor.

RE: Homemade auxiliary power for elevator

see: https://www.elevators.com/wp-content/uploads/docum... this one requires 30A service at 220V; that's 6.6 kVA; your drawing shows a total capacity of 780AH, which means you can run the elevation for maybe 12 minutes total time.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Homemade auxiliary power for elevator

Yes TooldToCare it works!
Now can you please self delete your hijack post?

Keith Cress
kcress - http://www.flaminsystems.com

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close