PLC Noob needing help

I am completely new to PLCs and was given the task of figuring out all the components needed, and to buy a panel accordingly. These are the components that I know I already have:

- Allen Bradley Micrologix 1200 PLC
1762L40BXB ABS 24 in 24VDC 16out Relay 24 VDC Power
- Allen Bradley Power Supply
1606-XL120D AB 24VDC 5AMP
- Allen Bradley Panelview 300

The input power to the system is 480V 3-phase. I have 14 digital inputs at 24V each. I also have 10 digital outputs at 110V each. I understand I will need relays for these outputs. Additionally, I know I'll need some sort of motor starter for a hydraulic pump that runs off of house power (480 3ph).

I'm looking for any advice as to what components such as relays, fuses, safety modules, motor starters, terminal blocks, etc that I will need. Finally, I need suggestions as to where I might purchase these components.

Thank you.

A start

The next thing you need is a transformer to drop the 480 supply down to 110v to power your output devices and, I'm assuming, your 24VDC supply. Transformers are rated in Volt/Amps. You'll need to get one capable of handling ALL of the loads simultaneously.

Automationdirect carries some of what you'll need - I think they even carry enclosures now.

Off the top of my head, you'll need: an enclosure - How big depends on how much stuff you're going to put in it. The specs. for the panel devices will include the physical dimensions, the device's 'footprint'; a disconnect; some method of labeling/marking the wiring; DIN rail, saves a lot of time mounting stuff.

You may not necessarily need relays for all of the outputs since the PLC has its own. It depends on how big a load you're looking at.

I won't dig up links for all these but, here are some manufactures I'm familiar with.

enclosures - Hoffman
wire marking - Panduit, Brady
relays/motor starters - Allen Bradley, Cutler Hammer
wire guide/trough (to make things neat inside the pane) - Panduit
wire ties - Panduit

For a local supplier, look in the yellow pages under "Industrial Controls".

Just wondering, is this a school project?

Yes, part of my Senior Project here at college. The guy that was doing our PLC research is in Mexico for a week and so I'm taking over until he gets back. I was hoping to impress him w/ my accomplishments... then I realized I knew nothing.

We have a supplier already for all our electrical components (www.kendallelectric.com) so that's a start. But our contact there won't be back until Monday so I wanted to learn as much as possible this weekend. I've learned a bit since my first post and think I've compiled a list of components that I will need in addition to the items I have. Please let me know how this looks and especially if I'm missing something:

(QTY) Description
------------------
(3) 600 VAC Fuse blocks
(1 or 2) 120 VAC Fuse blocks
(1 or 2) 24 VDC Fuse blocks
(1) Ground Bar
(1) Safety Relay
(1) 440V 3ph - 110V single phase transformer
(?) Terminal blocks
(1) Allen Bradley 700-HL Terminal Block Relay
(1) Motor Starter
(1) Overload Unit
(?) Fuse Block end barrier
(?) Terminal Block end barrier
(1) Disconnect Switch/handle/rod

A NEMA 12 Enclosure
Din Rail ... depending on enclosure size
Wiring

It looks pretty complete but, it seems there's always something forgotten.

What about fuses for the fuse blocks?

Any switches/lights/indicators on the cabinet door?

Hardware/screws for mounting everything?

I don't know how complete/extensive this needs to be but, it's really nice to have labels (Lamacoid'$ the be$T) on the backplane for the components. Something like, CR1, FU20, etc.

You don't show wire ties or wiring channel/trough. You'll probably need one or the other else the wiring will look like you threw red spaghetti in the cabinet.

Speaking of wire, what kind/gauge? THHN (with the nylon coating for gas/oil resistance) is usual in industrial applications.

Right now I'm not terribly concerned with wiring/labeling. Obviously this is an important component, however at this time I'm focusing on the main components that need to be ordered within the week and that will determine the overall panel size.

But as a side note:
MTW12AWG Black Wire
MTW16AWG Black Wire
MTW16AWG White Wire
MTW16AWG Green Wire
MTW18AWG Red Wire
MTW12AWG Blue Wire
2x3 Panduit Wire Duct (Black)
2" Panduit Wire Duct Cover
Buss Fuses

And I'll keep that suggestion for labels in mind. There shouldn't be any switches or anything on the cabinet door. Those will all be on the HMI panel, which I'm not terribly concerned about at this time. Though, I am coming up with more and more inputs. I haven't yet exceeded the 24 inputs though.

A tip on enclosures. Checl This link for a possable good deal: http://www.stores.ebay.com/id=90008658&ssPageName=L2

I usually can save about 20%-30% from hoffman or Automationdirect.

epic

Have you done a wiring diagram for the panel?

When I design a panel, the Bill Of Material (BOM) is usually the last thing done. I may preorder some components that I know will have a long delivery time but I generally do the electrical drawings first. After the drawings are done, it is much easier to get generate the BOM.

Begin by drawing the PLC I/O. Show all the components which will be connected to I/O, both inside the panel and external to the panel. Next, draw in the power wiring with fuses, transformers, power supplies, etc. Once this is done, the number of relays, fuses, terminal blocks is easily determined.

Vic,
You're absolutely right. Now if only I knew anything about wiring diagrams... Ah, the joy of having no EE's on the project. hehe. Thanks though, I'll look into it for sure.

Also, if ANYONE has a wiring diagram in ANY electronic format, I'd love the example. Thanks

[email protected]
subject: PLC wiring

What kind of (engineer?) senior student are we dealing with? Just curious. Sounds like NO background in electrical work. I hope you have someone qualified to review your project, before applying power.....ouch.

As for your labels, if this isn't a permanent set-up, then masking tape would do fine. I know it sounds cheap (it is), or you can get a cheap label maker ($20 - $30).

Well I guess you guy's are finished with this project by know. How did it turn out?

I am a Mechanical Engineer with no schematic background. The professor that reviewed my schematics said they were excellent. I replied, "for a mechanical?" to which he responded, "for anyone, they're some of the best I've ever seen."

We got labels figured out, and the wiring is almost done. One week to graduation. Ah, I live for crunch time. Yes, this will be reviewed before power is supplied. I appreciate all who've aided me.

Epic

Please let us know how it all goes for you.

Corkers

epic said:

Ah, I live for crunch time.

Click to expand...

Ah, I used to say that too, until every day became 'crunch time'...

Don't worry, it should wear off, given enough time. Not the 'crunch time', just the 'enjoyment' of it...

beerchug

-Eric

"Ah, I used to say that too, until every day became 'crunch time'...

Don't worry, it should wear off, given enough time. Not the 'crunch time', just the 'enjoyment' of it..."

Here I am sitting in the lab on a Sunday morning in the midst of one of what everything around here is turning out to be "crunch time" projects and I must have laughed out loud for about 15 minutes after I read Eric's post.

The voice of true experience!!!

Bob,

What time did you start this morning? I slept on the couch in my office last night and got up at 6:00 am this morning. I have to go to my sisters house at 11:00am for a family brunch, then I'll return here about 2:00pm. My kids call me Uncle Mike. My wife calls me "The soon to be EX".

Curnch time isnt quite like it used to be...

Mike.