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"Wiring Technique"

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TimothyMoulder - (49 posts) Dec-20-01, 06:51 AM (EST)

"Wiring Technique"

This should be a cakewalk for ya
Let's say we have a main panel and two sub-panels that we intend to connect via a pair of cables, main to sub, one each
In the main, we plan two terminal strips, one per sub-panel. Half the inputs and half the outputs are to go to each sub-panel.
My question is about grouping the I/O into these two terminal strips. Which of the following approaches do you think is best, and if you feel so inclined, why?
1.) Groups the terminals by Inputs and Outputs (ala break-out boards), distribute via cabling

TS1 (All Inputs)
I1I----------------------------I--(Sub-Panel 1)
I
I2I----------------------------I
I
I3I---------------------I----- I --(Sub-Panel 2)
I I
I4I---------------------I I
I I
TS2 (All Outputs) I I
I1I----------------------------I
I I
I2I----------------------------I
I
I3I---------------------I
I
I4I---------------------I
2.) Group the terminals by their destination sub-panels, Inputs then outputs
TS1 (Sub-Panel 1)
I1I(IN)------------------------I--(Sub-Panel 1)
I
I2I(IN)------------------------I
I
I3I(OUT)-----------------------I
I
I4I(OUT)-----------------------I

TS2 (Sub-Panel 2)
I1I(IN)------------------------I--(Sub-Panel 2)
I
I2I(IN)------------------------I
I
I3I(OUT)-----------------------I
I
I4I(OUT)-----------------------I

To my eye, the first seems to make more sense on a schematic, but the second seems more logical wiring-wise. What say you?
Thanks!
TM

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Table of contents

RE: Wiring Technique, TimothyMoulder, Dec-20-01, (1)
RE: Wiring Technique, rsdoran, Dec-20-01, (2)
RE: Wiring Technique, Terry_Woods, Dec-20-01, (3)
RE: Wiring Technique, Tom Jenkins, Dec-20-01, (4)
RE: Wiring Technique, Steve Bailey, Dec-20-01, (5)
RE: Wiring Technique, Rick Densing, Dec-20-01, (6)
RE: Wiring Technique, rsdoran, Dec-20-01, (7)
RE: Wiring Technique, elecplc, Dec-20-01, (8)
RE: Wiring Technique, kalle, Dec-21-01, (9)
RE: Wiring Technique, TimothyMoulder, Dec-21-01, (10)
RE: Wiring Technique, Barrington, Dec-21-01, (14)
RE: Wiring Technique, Tom Jenkins, Dec-21-01, (13)
RE: Wiring Technique, Tom Jenkins, Dec-21-01, (12)
RE: Wiring Technique, Terry_Woods, Dec-21-01, (11)

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TimothyMoulder - (49 posts) Dec-20-01, 07:38 AM (EST)

1. "RE: Wiring Technique"

Well, that got rather chopped up in the delivery, but i think you get the idea If you need more clarification, lemme know.
TM

Top

rsdoran - (332 posts) Dec-20-01, 07:48 AM (EST)

2. "RE: Wiring Technique"

I like both approaches but I think I like the first best..I assume that the inputs for sub panel 1 will be in sequence then sup panel 2 start the next sequence.
Example
Sub Panel 1 I:0/0 to I:0/7
Sub Panel 2 I:0/10 to I:0/15
I am sure there are more numbers involved but this was an example.
Ok I want to throw in a 3rd idea, I am sure you have considered it but I thought it worth mentioning.
What about master/slave or remote I/O?
Less wiring to deal with, one run of conduit normally for the communication cable and maybe 1 for the power leads if subs are powered from the main. Dont have to deal with the mess of pulling 50 wires or whatever is involved and ringing them out then numbering for associated I/O.
Its just a thought, and I am interested too in how others will approach this.

Top

Terry_Woods - (933 posts) Dec-20-01, 08:17 AM (EST)

3. "RE: Wiring Technique"

First, Tim, your ascii illustrations will come out a lot better if you delimit them with [CODE] and [/CODE].
Now, I prefer the second method, I/O grouped by destination - which is to say... modularizing.

+---+
| | +---+ +---+
| A | | A |--------> | A |------> A
| | | | +---+
| B | | B | +---+
| |---------> | | | B |------> B
| C | | C |--------> | C |------> C
| | | | | D |------> D
| D | | D | +---+
| | +---+
| |
| | +---+
| E | | E |---------------------> E
| | | |
| F |---------> | F | +---+
| | | |---------> | F |-----> F
| G | | G | | G |-----> G
| | +---+ +---+
+---+
That method keeps related I/O together (modular) and minimizes the amount of back-and-forth between panels when troubleshooting.
If you happen to have smart terminals (indicating) at each of the panels you can watch the local module as it operates. That should make troubleshooting quite easy.
When I create a system, the schematics reflect the modular nature of the system. The wire numbering then causes Inputs and Outputs to have a certain relative (modular) positioning. I then extend that modular scheme through all sub panels down to the final destinations in the process.
It's a great scheme if you are building from scratch. If you are revamping a system... it might or might not be possible. Then it depends on how much money and time you have.

Top

Tom Jenkins - (821 posts) Dec-20-01, 09:58 AM (EST)

4. "RE: Wiring Technique"

I agree with Terry - we use the second approach. The first may be more logical intellectually, but your panels should be designed for the guy in the field that has to install and troubleshoot the system. After all, lines on paper are easy no matter how you do it!
I also agree with the idea of substituting a communications link for hard wiring if your remote panels are anything more complicated than terminal junctin boxes. Instead of remote I/O we have gone to micro-PLCs in the remote panels. It isn't any more expensive than dumb I/O, and it lets you put alarming and equipment protection logic in the remote panel so you protect the machine even if the master dies.
One other level of separation we use is analog and DC discrete I/O from AC power and AC discrete I/O. Makes the wiring in the panel easier.

Top

Steve Bailey - (805 posts) Dec-20-01, 10:26 AM (EST)

5. "RE: Wiring Technique"

Either way is a good approach, but I prefer the second. When the panels are installed at the job site, the contractors are going to pull all of the wires between the main panel and sub-panel A at the same time. Same goes for sub-panel B. The person that hooks up the wires to the terminals will do a neater job if all of the terminations from a given bundle are on consecutive terminals. The person that has to check out the finished wiring will have an easier time also.

Top

Rick Densing - (189 posts) Dec-20-01, 01:08 PM (EST)

6. "RE: Wiring Technique"

Ditto to Steve

Top

rsdoran - (332 posts) Dec-20-01, 06:30 PM (EST)

7. "RE: Wiring Technique"

I was thinking along these lines.

Inputs
Panel A Panel B
||||||||||||||||||||||||||||||||X||||||||||||||||||||||||||||||
Inputs
||||||||||||||||||||||||||||||||X||||||||||||||||||||||||||||||
Outputs
||||||||||||||||||||||||||||||||X||||||||||||||||||||||||||||||
Outputs
||||||||||||||||||||||||||||||||X||||||||||||||||||||||||||||||
I did something similar to this not too long ago but I didnt have that many I/O involved so just used one ge fanuc with 2 long strips, 1 for inputs and 1 for outputs but the inputs matched the outputs to subpanel but at same time were sequntial on terminal strip.

Inputs
Panel A Rack 0 Slot 1 Panel B Rack 0 Slot 2
|||||||||||||||||||||||||||||||X|||||||||||||||||||||||||||||||
Outputs
Panel A Rack 0 Slot 3 Panel B Rack 0 Slot 4
|||||||||||||||||||||||||||||||X|||||||||||||||||||||||||||||||

I prefer remote I/O or master/slave but in this case I didnt have a choice and didnt have to do the wiring so I went with the flow.
Note: The X denotes a divider
I like the way Terry explained it. I think the modular concept makes more sense but as a troubleshooter type and if working from one plc I like all the inputs close and outputs close..I guess what I like is BOTH. That make sense?

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elecplc - (3 posts) Dec-20-01, 11:24 PM (EST)

8. "RE: Wiring Technique"

RS is a real moron. That isnt how its done you idiot.

Top

kalle - (87 posts) Dec-21-01, 05:21 AM (EST)

9. "RE: Wiring Technique"

According to the pecking order there has to be a "picking-chicken" in every chicken run.
It looks to me that RSDoran is choosen to be that one here, especially for spring chicken like "elecplc" that hasn't found their place in the chicken run!!!!!!

Top

TimothyMoulder - (49 posts) Dec-21-01, 07:05 AM (EST)

10. "RE: Wiring Technique"

LAST EDITED ON Dec-21-01 AT 07:08 AM (EST)
ElecPlc, that was un-called for.
RS, both are, I think, valid methods in particular situations, although I will side with age and wisdom that the modular approach is probably the best all-round. And I agree that the best of all possible worlds would be some method of uniting the two, although to my eye, they seem mutually exclusive.
Perhaps someone knows a third way? I have considered remote I/O in the past, but I'm mainly looking for wiring and cabling techniques here.
Thanks!

Top

Barrington - (93 posts) Dec-21-01, 08:34 AM (EST)

14. "RE: Wiring Technique"

It looks to me like rsdoran's method does combine both options.
The sub panels AND I/O are both segregated.
This would be easily wired, and easy for troubleshooting.

Sub Group
A B C
| |------------| |------------| |------------| |
| |xxxxxxxxxxxx| |xxxxxxxxxxxx| |xxxxxxxxxxxx| |<Inputs
| |------------| |------------| |------------| |
| |------------| |------------| |------------| |
| |oooooooooooo| |oooooooooooo| |oooooooooooo| |<Outputs
| |------------| |------------| |------------| |
| |------------| |------------| |------------| |

Top

Tom Jenkins - (821 posts) Dec-21-01, 08:16 AM (EST)

13. "RE: Wiring Technique"

I am stunned by your rapier like wit, elecplc! I only hope someday I can meet the high standard exemplified by your comments!

Top

Tom Jenkins - (821 posts) Dec-21-01, 08:14 AM (EST)

12. "RE: Wiring Technique"

Despite elecplc's highly professional and insightful comment, I understand what you are trying to do RS, and it is certainly rational. I fall back to a position I have stated many times - in areas like this it is most important to be consistent. If you have a system based on some logic, and you folow the pattern consistently, electricians and technicians will quickly learn to follow it. Ater all, what is the theoretical logical basis of black for hot and white for neutral and green for ground?

Top

Terry_Woods - (933 posts) Dec-21-01, 07:33 AM (EST)

11. "RE: Wiring Technique"

The modular method that I'm talking about does NOT separate Inputs from Outputs.
Starting in the field, a module consists of a particular set of Inputs and Outputs. Those Inputs and Outputs remain grouped together as a module right up until they are tied into the PLC.
That is, they are not separated into Inputs and Outputs until they are in fact wired into the Input and Output Terminals on the PLC!
A full explanation of what I'm talking about will require a full explanation of my "Design for Failure" Philosophy. I ain't ready to get into that - too big, too controversial.

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TimothyMoulder - (49 posts)	Dec-20-01, 06:51 AM (EST)
"Wiring Technique"
This should be a cakewalk for ya Let's say we have a main panel and two sub-panels that we intend to connect via a pair of cables, main to sub, one each In the main, we plan two terminal strips, one per sub-panel. Half the inputs and half the outputs are to go to each sub-panel. My question is about grouping the I/O into these two terminal strips. Which of the following approaches do you think is best, and if you feel so inclined, why? 1.) Groups the terminals by Inputs and Outputs (ala break-out boards), distribute via cabling TS1 (All Inputs) I1I----------------------------I--(Sub-Panel 1) I I2I----------------------------I I I3I---------------------I----- I --(Sub-Panel 2) I I I4I---------------------I I I I TS2 (All Outputs) I I I1I----------------------------I I I I2I----------------------------I I I3I---------------------I I I4I---------------------I 2.) Group the terminals by their destination sub-panels, Inputs then outputs TS1 (Sub-Panel 1) I1I(IN)------------------------I--(Sub-Panel 1) I I2I(IN)------------------------I I I3I(OUT)-----------------------I I I4I(OUT)-----------------------I TS2 (Sub-Panel 2) I1I(IN)------------------------I--(Sub-Panel 2) I I2I(IN)------------------------I I I3I(OUT)-----------------------I I I4I(OUT)-----------------------I To my eye, the first seems to make more sense on a schematic, but the second seems more logical wiring-wise. What say you? Thanks! TM
	Top

TimothyMoulder - (49 posts)	Dec-20-01, 07:38 AM (EST)
1. "RE: Wiring Technique"
Well, that got rather chopped up in the delivery, but i think you get the idea If you need more clarification, lemme know. TM
	Top

rsdoran - (332 posts)	Dec-20-01, 07:48 AM (EST)
2. "RE: Wiring Technique"
I like both approaches but I think I like the first best..I assume that the inputs for sub panel 1 will be in sequence then sup panel 2 start the next sequence. Example Sub Panel 1 I:0/0 to I:0/7 Sub Panel 2 I:0/10 to I:0/15 I am sure there are more numbers involved but this was an example. Ok I want to throw in a 3rd idea, I am sure you have considered it but I thought it worth mentioning. What about master/slave or remote I/O? Less wiring to deal with, one run of conduit normally for the communication cable and maybe 1 for the power leads if subs are powered from the main. Dont have to deal with the mess of pulling 50 wires or whatever is involved and ringing them out then numbering for associated I/O. Its just a thought, and I am interested too in how others will approach this.
	Top

Terry_Woods - (933 posts)	Dec-20-01, 08:17 AM (EST)
3. "RE: Wiring Technique"
First, Tim, your ascii illustrations will come out a lot better if you delimit them with [CODE] and [/CODE]. Now, I prefer the second method, I/O grouped by destination - which is to say... modularizing. +---+ \| \| +---+ +---+ \| A \| \| A \|--------> \| A \|------> A \| \| \| \| +---+ \| B \| \| B \| +---+ \| \|---------> \| \| \| B \|------> B \| C \| \| C \|--------> \| C \|------> C \| \| \| \| \| D \|------> D \| D \| \| D \| +---+ \| \| +---+ \| \| \| \| +---+ \| E \| \| E \|---------------------> E \| \| \| \| \| F \|---------> \| F \| +---+ \| \| \| \|---------> \| F \|-----> F \| G \| \| G \| \| G \|-----> G \| \| +---+ +---+ +---+ That method keeps related I/O together (modular) and minimizes the amount of back-and-forth between panels when troubleshooting. If you happen to have smart terminals (indicating) at each of the panels you can watch the local module as it operates. That should make troubleshooting quite easy. When I create a system, the schematics reflect the modular nature of the system. The wire numbering then causes Inputs and Outputs to have a certain relative (modular) positioning. I then extend that modular scheme through all sub panels down to the final destinations in the process. It's a great scheme if you are building from scratch. If you are revamping a system... it might or might not be possible. Then it depends on how much money and time you have.
	Top

Tom Jenkins - (821 posts)	Dec-20-01, 09:58 AM (EST)
4. "RE: Wiring Technique"
I agree with Terry - we use the second approach. The first may be more logical intellectually, but your panels should be designed for the guy in the field that has to install and troubleshoot the system. After all, lines on paper are easy no matter how you do it! I also agree with the idea of substituting a communications link for hard wiring if your remote panels are anything more complicated than terminal junctin boxes. Instead of remote I/O we have gone to micro-PLCs in the remote panels. It isn't any more expensive than dumb I/O, and it lets you put alarming and equipment protection logic in the remote panel so you protect the machine even if the master dies. One other level of separation we use is analog and DC discrete I/O from AC power and AC discrete I/O. Makes the wiring in the panel easier.
	Top

Steve Bailey - (805 posts)	Dec-20-01, 10:26 AM (EST)
5. "RE: Wiring Technique"
Either way is a good approach, but I prefer the second. When the panels are installed at the job site, the contractors are going to pull all of the wires between the main panel and sub-panel A at the same time. Same goes for sub-panel B. The person that hooks up the wires to the terminals will do a neater job if all of the terminations from a given bundle are on consecutive terminals. The person that has to check out the finished wiring will have an easier time also.
	Top


	Rick Densing - (189 posts)	Dec-20-01, 01:08 PM (EST)
	6. "RE: Wiring Technique"
	Ditto to Steve
		Top


	rsdoran - (332 posts)	Dec-20-01, 06:30 PM (EST)
	7. "RE: Wiring Technique"
	I was thinking along these lines. Inputs Panel A Panel B \|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|X\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\| Inputs \|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|X\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\| Outputs \|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|X\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\| Outputs \|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|X\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\| I did something similar to this not too long ago but I didnt have that many I/O involved so just used one ge fanuc with 2 long strips, 1 for inputs and 1 for outputs but the inputs matched the outputs to subpanel but at same time were sequntial on terminal strip. Inputs Panel A Rack 0 Slot 1 Panel B Rack 0 Slot 2 \|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|X\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\| Outputs Panel A Rack 0 Slot 3 Panel B Rack 0 Slot 4 \|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|X\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\| I prefer remote I/O or master/slave but in this case I didnt have a choice and didnt have to do the wiring so I went with the flow. Note: The X denotes a divider I like the way Terry explained it. I think the modular concept makes more sense but as a troubleshooter type and if working from one plc I like all the inputs close and outputs close..I guess what I like is BOTH. That make sense?
		Top


	elecplc - (3 posts)	Dec-20-01, 11:24 PM (EST)
	8. "RE: Wiring Technique"
	RS is a real moron. That isnt how its done you idiot.
		Top


	kalle - (87 posts)	Dec-21-01, 05:21 AM (EST)
	9. "RE: Wiring Technique"
	According to the pecking order there has to be a "picking-chicken" in every chicken run. It looks to me that RSDoran is choosen to be that one here, especially for spring chicken like "elecplc" that hasn't found their place in the chicken run!!!!!!
		Top


	TimothyMoulder - (49 posts)	Dec-21-01, 07:05 AM (EST)
	10. "RE: Wiring Technique"
	LAST EDITED ON Dec-21-01 AT 07:08 AM (EST) ElecPlc, that was un-called for. RS, both are, I think, valid methods in particular situations, although I will side with age and wisdom that the modular approach is probably the best all-round. And I agree that the best of all possible worlds would be some method of uniting the two, although to my eye, they seem mutually exclusive. Perhaps someone knows a third way? I have considered remote I/O in the past, but I'm mainly looking for wiring and cabling techniques here. Thanks!
		Top


	Barrington - (93 posts)	Dec-21-01, 08:34 AM (EST)
	14. "RE: Wiring Technique"
	It looks to me like rsdoran's method does combine both options. The sub panels AND I/O are both segregated. This would be easily wired, and easy for troubleshooting. Sub Group A B C \| \|------------\| \|------------\| \|------------\| \| \| \|xxxxxxxxxxxx\| \|xxxxxxxxxxxx\| \|xxxxxxxxxxxx\| \|<Inputs \| \|------------\| \|------------\| \|------------\| \| \| \|------------\| \|------------\| \|------------\| \| \| \|oooooooooooo\| \|oooooooooooo\| \|oooooooooooo\| \|<Outputs \| \|------------\| \|------------\| \|------------\| \| \| \|------------\| \|------------\| \|------------\| \|
		Top


	Tom Jenkins - (821 posts)	Dec-21-01, 08:16 AM (EST)
	13. "RE: Wiring Technique"
	I am stunned by your rapier like wit, elecplc! I only hope someday I can meet the high standard exemplified by your comments!
		Top


	Tom Jenkins - (821 posts)	Dec-21-01, 08:14 AM (EST)
	12. "RE: Wiring Technique"
	Despite elecplc's highly professional and insightful comment, I understand what you are trying to do RS, and it is certainly rational. I fall back to a position I have stated many times - in areas like this it is most important to be consistent. If you have a system based on some logic, and you folow the pattern consistently, electricians and technicians will quickly learn to follow it. Ater all, what is the theoretical logical basis of black for hot and white for neutral and green for ground?
		Top

Terry_Woods - (933 posts)	Dec-21-01, 07:33 AM (EST)
11. "RE: Wiring Technique"
The modular method that I'm talking about does NOT separate Inputs from Outputs. Starting in the field, a module consists of a particular set of Inputs and Outputs. Those Inputs and Outputs remain grouped together as a module right up until they are tied into the PLC. That is, they are not separated into Inputs and Outputs until they are in fact wired into the Input and Output Terminals on the PLC! A full explanation of what I'm talking about will require a full explanation of my "Design for Failure" Philosophy. I ain't ready to get into that - too big, too controversial.
	Top

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