Recomendations?

BDKuhns

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Join Date
Sep 2003
Location
KC, MO
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This question pertains to my post Pico inputs? a while back. I've looked at several different ways to perform the task I'm attemptint to do. the ABB-KRD sereis relays look good, but I need one more additional controllable output.
What I need is a "Controllable relay" or "PLC" that would allow two user controlled potentiaometers to controle three 120VAC outputs. One of the outputs will need at least a 10A max output capability.
Does anyone have a suggestion for a simple (and cost-effective) product that will perform the above.
Thanks.
 
I am not real versed on AB's product line of options and model mumbers. I think that AB only offers two expansion modules, a 12 ac in /8 ac out or a 12 dc in / 10 dc out. The AC units are supposed to have 8 amp contacts. This is heavier then what moeller and the others had advertised. I would think a Moeller expansion could work, but don't want to say.

So far, the programs and software are interchangable.

The AB Picos are derived from the Moeller "easy" units. Moeller manufacures and relabels for quite a few companies.

Moeller's model "EASY619-AC-RC" and an "EASY202" expansion module with (2) 10 amp relay outputs wold be what you need.

Why dio you need 10 amp contacts. DO NOT switch 10 amp motor or lamp loads with a plc. In fact, 10 amps continuous through 10 amp contacts should be considered a no-no!

As I have said before, I am waiting for Mitsubishi to bring out their version of the Pico, and call it an "Istsy Bitsy Mitsi".


regards.....casey
 
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ok????

Ok, I am confused. Is AB (Allen Bradley) the same maker as ABB/SSAC? I was under the belief that they were not the same.
I'll look at both manufacturers you suggest. I learn something every time I'm on this site.
My task is realy very simple, but I am having difficulty solving it without three individual timed relay's. I wish to do it with some of the smaller PLCs in order to obtain experience with them. I was also hoping to see if there was a multi-function (3 or more timed outputs) TDR that would solve this issue.
The 10A was just a target so that the TRD would not be overloaded. It is going to controle the start and stop of a 3A FLA motor. The motor has it's own protection.
Thanks.
 
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BDKuhns...
(this is a little late but I'll post it as is... and then read BD's latest)

Your posting is confusing...

Are you looking for a way to make the Pico handle this situation, or are you looking for a way to handle this situation?

You said...
"What I need is a "Controllable relay" or "PLC" that would allow two user controlled potentiaometers to controle three 120VAC outputs. One of the outputs will need at least a 10A max output capability.
Does anyone have a suggestion for a simple (and cost-effective) product that will perform the above."


First, as far as an output that can handle 10A...

NEVER, NEVER, NEVER, (get my point?) NEVER use a PLC or similar type controller to provide 10A directly. Use the output of the device to control a relay that is rated to handle at least 10A continuously.

Second, as far as having two separate analog inputs controlling ANY number of outputs...

Who is the boss? If "Station-A" says go slow and "Station-B" says go fast... who has control?

This can not be... what is your real intent?

90% of any solution comes from properly understanding the question!
 
The Total Story!

In order to clarify this all, I'l try to use some of the vB codes
to show a discription. (please be patient with this)

 
user input (times)

1. Vac-time (pot-#1)
2. seal-time (pot-#2)
Outputs
1. vac motor (controled by pot-1)
2. seal bladder/seal heat bar (controled by pot-2)
3. vac seal sol (2sec delay off after seal heat)




swtch
vac motor|------------------------
|------------|

|-------|
seal |------------------------- ----|


v-sol |-------------------------------------|


The "vac" has two time delays. A variable time-1 (low) till a
variable interaval time-2 (high) then off.
the vac sol will have a 2sec delay on off after the vac time 2
goes low.

Hope this is any clearer.

 
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Who has to adjust the pots to set the time durations and how often do they need to be adjusted?

The GE Fanuc VersaMax Micro has two pots that can be used as timer presets. The drawback is that they are located on the PLC itself and you need a little screwdriver to adjust them. That renders them less than ideal for frequent adjustment by an operator, but OK for infrequent adjustments.

You can get a starter kit that includes the PLC, programming software and download cable for under $200. The outputs won't handle 10 amps, but like Terry, for a load that size I'd use an isolating relay anyway.
 
Is there possibly a TDR that has 3 or 4 controlable outputs?
The only ones that I can find (so far) have a SPDT set up with two timing sequences (intervals).
 
Basically, your expanded explanation is more confusing.

You can run a vacuum pump for three days... if it isn't developing a vacuum in all that time then your purpose is defeated.

You simply need to do the following...

1. load a bag
2. apply a vacuum (valve? pump?)
3. monitor that the vacuum is developed (vacuum sensor switch)
4. seal the bag for such-n-such time (pot adjustment)
5. release the sealer
6. delay (pot-2?)
7. shut-off the vacuum source (valve? pump?)


You simply need to apply a vacuum sensor to the evacuated area. This is an adjustable, digital-type sensor (these are cheap... $15 -$20 apiece). When the vacuum is developed the contact closes. Then, and only then, begin your sealing process for whatever time the pot is set to. When the sealing timer times out, release the sealer and then begin your 2-sec delay before releasing the vacuum.



+-----------------------------------+
VACUUM VALVE | |<---+
----+ +-- |
|
+-------------------------- | --+
VACUUM SENSOR |-+ | |
---------------+ | | +---
+----+ |
| +-------------+------ |
SEAL TIMER +->|//POT-TIMED//|--+ |
---------------+-------------+ | |
| |
+-------------+ | |
SEAL | |<-+ |
---------------+ +- | ----- |
| |
+-----+ |
| +-----------+-- |
DELAY BEFORE RELEASE +->|///2-sec///|---+
-----------------------------+-----------+



Notice that you only need one pot for your seal-time.
 
Sounds like a sealer

BD,
Since you mentioned a seal bar and your logic seems to be targeted to a sealer I assume your trying to make a sealer, whether stand alone or on an existing process. Some of the sealer companies are using that little mitsubishi PLC (I have forgotten the 2 letter designatator) but their using it becuase it has a couple o potentiometer inputs. The Allen Bradley Pico does have one analog input I think so youd have to have 3 to control the individual functions and then talk to each other. You could look at the Wago mini plc that connects to their I/O which would allow you to configure the I/O to suit you as another option. If its a stand alone sealer, have 2 air valves on the clamp cylinder, the first applies 20 psi or so and if the seal bar makes it down all the way, then you make a prox switch which turns on the 2nd higher pressure valve to apply the force needed make a good seal. Also if your not cooling the bar, it will heat up with each cycle and this changes the time you need to get a uniform consistent seal. It also changes the hold time. If your using a vertrod style with water flowing through the bar, then seal as fast as you want. Theres a buttload of information I've learned the hard way about sealer bars and systems and dont think the sealer companies have a handle on it, theyre clueless about how we use them in the feild, they think one seal every 30 seconds is a lot. They also dont close the loop, by monitoring the sealer bar temp, you can adjust(automatically) the seal time and cool time. This is a must if you dont cool the bar. blah blah, guess that enough for now.

Good Luck
 
Most of the bag sealers I've seen ain't very 'smart'. They just fire off their sequence without checking for anything. Unless Barry plans to improve the machine (which isn't a bad idea), I think a PLC (and even a smart relay) is overkill for this application.

Just throw in 3 timers and be done. Something like the little 'power cube' SSAC timers (LINK) will handle the load, are available with different timing fuctions, and can use an externally mounted pot.

To figure out which timing functions you need, SSAC has a handy selection guide HERE, with animations... :cool:

beerchug

-Eric
 
3 amp output x 7 for inrush=21 amps. Use a contactor for a start.

You do not require 3 outputs off a timer, just 3 timers, or, if you wish, 3 compare functions off the same timer to give you the 3 outputs.

Am I reading this incorrectly?
 

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