You are not registered yet. Please click here to register!


 
 
plc storereviewsdownloads
This board is for PLC Related Q&A ONLY. Please DON'T use it for advertising, etc.
 
Try our online PLC Simulator- FREE.  Click here now to try it.

---------->>>>>Get FREE PLC Programming Tips

New Here? Please read this important info!!!


Go Back   PLCS.net - Interactive Q & A > PLCS.net - Interactive Q & A > LIVE PLC Questions And Answers

PLC training tools sale

Reply
 
Thread Tools Display Modes
Old February 12th, 2020, 01:19 AM   #16
dogleg43
Member
United States

dogleg43 is offline
 
Join Date: Dec 2005
Location: Indiana
Posts: 383
Quote:
Originally Posted by Firejo View Post
This would be a three position terminal block

https://www.alliedelec.com/product/p...7022/70054840/
Fair enough.

An Allen-Bradley 1492-WTF3 is an example of what I was thinking of.

337DB93A-F049-4C12-A05B-20C2FBC98BA7.jpeg
  Reply With Quote
Old February 12th, 2020, 02:03 AM   #17
willxfmr
Lifetime Supporting Member
United States

willxfmr is offline
 
willxfmr's Avatar
 
Join Date: Nov 2013
Location: Wisconsin
Posts: 403
Quote:
Originally Posted by dogleg43 View Post

My final comment is to just make sure the electricians terminating spring clamp terminals understand how to do it properly.
I prefer the screw clamps for this very reason. I worked 3 years with a guy on the shift ahead of me that couldn't figure out how to get a wire in a spring clamp without it either falling out, or being in so far that the clamp was on the insulation not the wire. Of course he was better than the guy who wired a small control box using StaCons and never crimped any of them...


Bubba.
__________________
“Now will come the nay-sayers with all the reasons why you shouldn't do this. Some of them are teachers, and some of us are doers. Besides, you have got to let the smoke out of this equipment every now and then, or it starts to clog up the chimney.”
~Lancie1
  Reply With Quote
Old February 12th, 2020, 03:01 AM   #18
JesperMP
Lifetime Supporting Member + Moderator
Denmark

JesperMP is offline
 
JesperMP's Avatar
 
Join Date: Feb 2003
Location: Copenhagen.
Posts: 14,091
For me spring clamps or "cage clamps" as they are sometimes called.

The problem with the electrician not understanding how to use cage clamps is IMO positively offset by the fact that you can see what you are doing due to that you usually insert the wire from the front.
On screw terminals you insert the wires from the side so you are effectively doing it blind. Have experienced numerous problems due to wires inserted wrongly.

For screw terminals I have also experienced plants where the local electrician failed to tighten the screws on every single terminal. With cage clamps, at least they are self tightening.

Dont group cage clamp terminals together with push-in terminals. I love cage clamp, and I hate push-in terminals. Sadly, push-in terminals seems to be the new standard in PLC I/O cards.
__________________
Jesper
See my profile interests for Q&A
  Reply With Quote
Old February 12th, 2020, 06:00 AM   #19
PLC Pie Guy
Member
Canada

PLC Pie Guy is offline
 
PLC Pie Guy's Avatar
 
Join Date: Jun 2013
Location: Halifax
Posts: 895
Quote:
Originally Posted by JesperMP View Post
For me spring clamps or "cage clamps" as they are sometimes called.

The problem with the electrician not understanding how to use cage clamps is IMO positively offset by the fact that you can see what you are doing due to that you usually insert the wire from the front.
On screw terminals you insert the wires from the side so you are effectively doing it blind. Have experienced numerous problems due to wires inserted wrongly.

For screw terminals I have also experienced plants where the local electrician failed to tighten the screws on every single terminal. With cage clamps, at least they are self tightening.
They need a new electrician! These are non-issues to somebody paying attention.
I hate broken spring terminals!
Screw terminals always!
  Reply With Quote
Old February 12th, 2020, 06:07 AM   #20
dogleg43
Member
United States

dogleg43 is offline
 
Join Date: Dec 2005
Location: Indiana
Posts: 383
Quote:
Originally Posted by JesperMP View Post
For me spring clamps or "cage clamps" as they are sometimes called........The problem with the electrician not understanding how to use cage clamps is IMO positively offset by the fact that you can see what you are doing due to that you usually insert the wire from the front.
Group cage clamp terminals together with push-in terminals. I love cage clamp, and I hate push-in terminals. Sadly, push-in terminals seems to be the new standard in PLC I/O cards.
Jesper, What is the difference between spring clamp/cage clamp terminals & push-in terminals?

I’ve always used those terms interchangeably.
  Reply With Quote
Old February 12th, 2020, 06:26 AM   #21
JesperMP
Lifetime Supporting Member + Moderator
Denmark

JesperMP is offline
 
JesperMP's Avatar
 
Join Date: Feb 2003
Location: Copenhagen.
Posts: 14,091
In the push-in terminals you do not have to insert a screwdriver to open the clamp.
If you use stiff wires or wires with ferrules you can literally just push the wire in.

The spring force of the tab that gets pushed in is very weak. The only thing that keeps the wire in place is the sharp edge on the tab that gets pushed in. It is very easy to deform the tab since it is quite flimsy. It just takes that you insert the wire at too steep an angle, or wiggle the wire a bit. And you wont know that the tab has been weakened since it is very hard to see.

The spring force in a cage clamp terminal is much stronger. And the design is generally much more robust. It is possible to damage a cage clamp terminal, but it takes some deliberate force to do so.

Also, with push-in terminals you can squeze 50% more wire ports in the same space as you can with cage clamp or screw terminal. So the PLC manufacturers are using this "advantage" to squeze ever more channels into the same space. We have 16-channel modules where in the past we would have 4 or 8-channel modules. This is an improvement that I did not ask for.
__________________
Jesper
See my profile interests for Q&A
  Reply With Quote
Old February 12th, 2020, 01:53 PM   #22
diat150
Lifetime Supporting Member
United States

diat150 is offline
 
Join Date: Mar 2006
Location: Louisiana
Posts: 1,325
Ill never use screw terminals again unless a customer forces me. push in are better in every aspect.
  Reply With Quote
Old February 12th, 2020, 01:59 PM   #23
ndzied1
Lifetime Supporting Member
United States

ndzied1 is offline
 
ndzied1's Avatar
 
Join Date: Aug 2002
Location: Chicago, Illinois
Posts: 2,475
For some that are not clear on the major types of terminals, here is a nice little video I found on YouTube.

https://youtu.be/oFSt8Y71WZE
__________________
nOrM
======================
nOrM=Norman Dziedzic Jr.
I've never been to China but my phone has.
  Reply With Quote
Old February 13th, 2020, 11:15 AM   #24
bill4807
Member
United States

bill4807 is offline
 
Join Date: Mar 2013
Location: michigan
Posts: 170
Over time I have moved from screw terminal to spring clamp/cage clamp style.
I find them easier to wire, and to many times i have had to troubleshoot and fix wires that were landed on the insulation from screw terminals.

Also I have noticed during shipping of some machines some of the screw terminals have loosened, probably because they weren't landed correctly from the beginning.

Also in tight ductwork the spring clamps give more room for your fingers since they are on more of the front of the block as opposed to the top and bottom like screw terminals.
  Reply With Quote
Old February 13th, 2020, 11:20 AM   #25
Rson
Member
United States

Rson is offline
 
Join Date: Jun 2017
Location: Michigan
Posts: 254
I prefer screw terminal connections.

Industrial control wiring is stranded-wire. If it were solid wire, the push-in clamp style would be perfect (like a bread-board in digital electronics). If you use push-in clamp terminals, ferrules are a must IMO.

The best of both worlds are the clamps like you would see on an Allen Bradley 1606 power supply. They have a physical lever that clamps the wire shut. It isn't feasible on many other applications, however.
  Reply With Quote
Old February 13th, 2020, 01:12 PM   #26
Toine
Member
Netherlands

Toine is offline
 
Join Date: Nov 2016
Location: NL
Posts: 275
Quote:
Originally Posted by dogleg43 View Post
I moved into engineering and design and my opinion changed after using Wago & Phoenix spring clamp terminals for control wiring (stranded #16 & smaller) on some industrial panels. The connections seemed to hold up well and it was a space saver in the panels because less space is required between the terminals and the wiring duct.

We have been using these for many years, in my experience they are faster to use and more reliable than screw type terminals. The spring determines the force on the connection, no more electricians either fastening too hard, too loose, or forgetting to properly fasten entirely. Cage clamps are resistant to vibration. Screw terminals need to be checked and retightened on a regular basis, which just does not happen. For this reason spring clamp terminals are a requirement in some sectors. Railways, ships spring to mind (pun intended), just about anything moving or vibrating.
  Reply With Quote
Old February 13th, 2020, 03:08 PM   #27
Aabeck
Member
United States

Aabeck is offline
 
Aabeck's Avatar
 
Join Date: Feb 2013
Location: Detroit
Posts: 1,644
My background started in industrial maintenance. Even if a spring terminal is rated for so many insertions, the plastic degrades so by the time I have to get in the panel pushing a screwdriver in to release usually cracked the plastic.

I even have to work on small relatively new Mitsubishi VFD's with spring terminals and even the customer has taken to cutting the wires a few inches out instead of trying to get the wire out, then using a handfull of wire nuts to reinstall.

+1 screw terminals only!
__________________
Never underestimate the quality of idiots that will be running your machines
http://aabeck.com
  Reply With Quote
Old February 13th, 2020, 03:43 PM   #28
kvogel
Member
United States

kvogel is offline
 
Join Date: Jan 2011
Location: Colorado
Posts: 95
Changed from screw terminals to spring terminals, will never go back.

To many failures with screw terminals, either loose connections or spread, broken terminal housings due to overtightening.

I have only has a tiny number of failures with spring terminals and they are obvious at the install unlike with loosening screw terminals.

Wiring is also WAY faster with spring terminals.

Cheers

Ken
  Reply With Quote
Old February 13th, 2020, 03:47 PM   #29
Rson
Member
United States

Rson is offline
 
Join Date: Jun 2017
Location: Michigan
Posts: 254
I'm just curious - with regard to UL certifications - usually you need a torque screwdriver / etc for screw terminals.

I'd imagine that all goes away with push-in or spring terminals. That would probably be worth it alone for those doing UL listed panels.
  Reply With Quote
Old February 13th, 2020, 07:48 PM   #30
rupej
Member
United States

rupej is offline
 
Join Date: Sep 2014
Location: NC
Posts: 716
Quote:
Originally Posted by Rson View Post
I'm just curious - with regard to UL certifications - usually you need a torque screwdriver / etc for screw terminals.

I'd imagine that all goes away with push-in or spring terminals. That would probably be worth it alone for those doing UL listed panels.
It's true.
  Reply With Quote
Reply
Jump to Live PLC Question and Answer Forum

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Topics
Thread Thread Starter Forum Replies Last Post
terminal block technology MNJ96 LIVE PLC Questions And Answers 23 February 17th, 2020 05:49 PM
Rotary Index Table app. gpdc LIVE PLC Questions And Answers 1 September 20th, 2007 01:22 PM
Air compressor screw type - questions leitmotif LIVE PLC Questions And Answers 7 September 11th, 2007 06:02 AM
melsec type A0J2 and MAC E200 terminal? ason LIVE PLC Questions And Answers 10 January 17th, 2007 01:22 PM
OT Cage Clamp Terminals MikeW LIVE PLC Questions And Answers 15 January 19th, 2005 09:29 AM


All times are GMT -5. The time now is 09:53 AM.


.