×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

*
*
*
*

Thanks. We have received your request and will respond promptly.

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

Three single-phase SSRs in place of one three-phase, with zero-cross

thread240-501787

Three single-phase SSRs in place of one three-phase, with zero-cross

Three single-phase SSRs in place of one three-phase, with zero-cross

(OP)
Hi Everyone,

We are having trouble getting three-phase sold-state relays. These are used to power a resistive heater load - in some instances a single heater is across two of the phases, and in others three heaters are distributed across the phases. I was able to find a single-phase SSR that otherwise has similar ratings to the normal 3Φ SSR we use (and for less than a third the cost!). Both SSRs have a zero-cross feature. Will there be any issue using three 1Φ SSRs? I am mainly worried that the zero-cross feature will not coordinate between phases, but I have trouble thinking that through.

Thanks!

RE: Three single-phase SSRs in place of one three-phase, with zero-cross

For simple on / off use, I don't understand there being an issue. You have 1 or 3 single phase objects that apparently have no sync required. That the SSRs are opto coupled, they are independent of their power source. I think it's irrelevant about phase sync and zero cross. Besides, the SSRs don't "know" or determine zero cross, they respond to it. Power control would work by using the thermal inertia of the heaters - X cycles on and Y cycles off.

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

Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now
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