# terminal blocks



## gesparky221 (Nov 30, 2007)

I try to bring all the inputs to a terminal strip and the outputs to din rail fuse blocks. This makes future wiring much easier. It also is easier to troubleshoot on the din rail terminal block than the plc I/O card. I started fusing all the outputs a few years ago so I don't have to shut the plc down to pull the card if a fuse blows. The plc's I use, (GE) have high density cards that have a plug in cable than gets terminated on a strip.


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## denny3992 (Jul 12, 2010)

i like the 9030 series we are primarily an ab company but got into ge for a customer and really like the versatility of the 9030!


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## denny3992 (Jul 12, 2010)

ab has a similar setup for prewired cards to cables, not really a fan.


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## bill39 (Sep 4, 2009)

denny3992 said:


> how many of you when installing a plc take inputs and outputs to terminal blocks before going to field wiring ?



Two good reasons to always take the I/O to terminals:
Ease of troubleshooting.
Future upgrades are easier. No danger of the field wiring being too short if a different style of PLC or module are used.
.....and please, please, please, ALWAYS USE WIRE #'S.


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## alcelectrician (Mar 29, 2012)

I look at it this way, if i have the room to put terminal blocks in for all the inputs and outputs then i will but if i dont have the room then i make do


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## Tsmil (Jul 17, 2011)

Amount of space is always the deciding factor. Always for new panel designs.


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## alcelectrician (Mar 29, 2012)

exactly, when u r designing new panels and u r limited to the size of panel, u might not have enough room to put all the inputs and outputs on terminal blocks. i just always go for keeping it neat


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## denny3992 (Jul 12, 2010)

imo they should go to terminals! with the stacked blocks, unless its a tight retro theres no reason not to! and yes fusing is mui impotante


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## gesparky221 (Nov 30, 2007)

I always use the input and output number for the field wiring. Makes it a lot easier to track down a problem. We also label all of our sensors with the input numbers.


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## John Valdes (May 17, 2007)

I always, every single time, mount terminal blocks for every wire that leaves the enclosure. Always.
This is so I can build my control panel, test it on the bench and take the panel to the job and mount it. Then anyone that can count (read numbers) can connect it. Every terminal block is numbered corresponding with wire number.




alcelectrician said:


> exactly, when u r designing new panels and u r limited to the size of panel, u might not have enough room to put all the inputs and outputs on terminal blocks. i just always go for keeping it neat


Insist if you are building the panel, that you choose/order the enclosure and back board.
I have had managers, PA's and others scoff at the size of the panels I have ordered. (they are not cheap) When the job is done, they scoff no more as everything fits in nice and neat.


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## greenman (Apr 20, 2012)

For outputs I like using an isolating relay, so the plc card does not blow contacts or a fuse block.
http://www.phoenixcontact.ca/company/search.jsp?q=isolation+realy&x=12&y=10
INTERBUS ST digital output modules for AC voltages
The digital INTERBUS output modules are designed for the connection of digital actuators, such as *electromechanical valves*, contactors or lamps.
In addition to the standard IB ST 24 BDO modules, the range is rounded off by modules with extended functionality.
The scope of functions provided by the standard models covers the majority of applications. On top of this, several modules provide additional electronic functions, such as:
- Output channels in up to four electrically isolated groups
- Separate electronic short-circuit protection for each output channel
- Higher output current
which are needed in individual applications.
All the typical advantages of INTERBUS-ST handling, such as multi-wire connection methods and plug-in electronics are provided by both product lines.
Phoenix Contact make some cool stuff
Input i run to an isotaion block so if you half to change a prox cable you just open the block. Or one isolation block per card


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## Inphase (May 5, 2012)

I'm surprised no one has mentioned fusing inputs individually as well, a good practice as well. Terminals are a must also, ever tried to jumper an input on an active plc card...not nearly as fun as with terminals.


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