plc help

[danl]

awesome suggestions. i'm going to dive into their site a bit deeper later on and see all the stuff they have. looks like this may very well be a one stop shopping spree for me. thanks for all ya help. building this system is long overdue and i know its going to be enjoyable for me.

 

[OkiePC]

Personally, I would use cheap and readily available DC outputs on the Click. Then get some simple plug in relays for the real world 24vac solenoids. The DC output card may last forever so long and the relay coils and wiring are all in the same box and good craftsmanship is applied. If one of the isolation relays fries...slap a new one in the socket for $5-$10. Cheap plug in relays can easily handle 2amp loads, and if something goes haywire at the load (solenoid) like a gopher chewing through a cable, for example...the relay contact may weld or burn open, but the coil circuit attached to the PLC should rarely if ever present a problem for the more expensive PLC output card.

Automation Direct is awesome for their prices and delivery times. The only complaint I have ever had about their products were for some defective terminal blocks (8 years ago) and cheesy fuse holders we bought from them. I have used their Fuji branded contactors and MCBs, enclosures, transformers, relays, and a bunch of other stuff with zero problems.

 

[Lancie1]

Personally, I would use cheap and readily available DC outputs on the Click.

Paul, That's what I was going to recommend also. . . until I calculated how much the 7-Amp-per-relay output module was going to cost per relay: $44 divided by 4 = $11 per relay! If you bought a relay with 7-amp contacts and with a plug-in base, it could easily cost more than $11, so in this case it may be a toss-up.

It looks like Dan could go either way with the Click, either internal auxiliary relay modules, or internal extra outputs with external relays. He will need some type of extra output module anyway, because he needs more than the built-in 6 outputs on the largest Click, so buying two of the 4-point Click CO-04TRS output modules will still be a good choice.

Compare two CO-04TRS 7-Amp relay output modules (2 X $44 = $88) with one CO-08TA transistor output module plus 8 external relays with bases (1 x $50) + (8 x $15) + (8 x $4.50) = $188

 

[danl]

hi y'all, well i checked into the valves i got and it turns out they have these ratings. .30 amp (7.2 va inrush 5.5 va holding) and .30amp (.30 inrush and .19 holding). now, i'm going to tie two of the 7.2 inrushes together seeing that those valves always have to work together and the rest can get their power from another transformer.
none the less, seeing that i'll be using a 115 X 24 vac step down transformer what would y'all recommend for a secondary side 24 vac amp rating? the regular valves are .30 inrush and .19 holding. the two mains tied together are 7.2 inrush and 5.5 holding.? would i be assuming one transformer at 24vac at least 15 amp and the other being 2 amp?

 

[Lancie1]

Would I be assuming one transformer at 24vac, at least 15 amp, and the other being 2 amp?

Dan, If it were my project, I would use the following:

One 120 volt AC circuit from you main panel, which splits to two feeds:

one 120 volt feed supplies power the two pumps (you need fuses for each pump) and maybe to a Click 120 VAC PLC (or to a 24 Volt DC Click with a 24 volt 2 Amp DC power supply). If you use the DC version of the Click, then you have to have a 24 volt DC power supply, which could also be used power your input sensors. Note that a DC power supply does not really need a transformer, because most of them today do not use transformers but instead use switching transistors to lower the voltage, and then run it through rectifers and filters.

The other 120 volt fused feed supplies power to one 120/24 volt, 240 volt-amp (VA), 10 Amps at 24 VAC, transfomer to power the solenoids and any other 24 VAC devices.

I think you will need two of the Click 7-amp four-output isolated relay modules to control your two 120 volt pumps (if you use the PLC to start/stop those). That would give you a eight 7-amp outputs and six 1-amp outputs, or 14 total outputs (you said you needed 12).

 

[danl]

time to order

these are the items that just may do the trick.
plc-
1 click model co-01dd2-d. has a real time clock battery back-up memory, 8 dc 24vdc ins (for the level switches)and 6 24vdc outs for valve solenoids.( i take it that dc will power the ac solenoids at .1 amp?)
2 click spdt 7 amp relays. co-04trs.(for the 2 pump relay starters and valve solenoids using the step down transformer.
1 co-o1ac power supply (for the plc).
1 120vac 250va v 24 vac 10.4 a transformer ph250pg.(for pumps and some of the valve solenoids).
pump starters and fuses.... still looking...
let me know if what i got so far fits the bill. the outputs (6) on the plc are strictly 24 vdc @ .1 amp per point. not sure how this would handle an inrush at the valve solenoid though. maybe another relay block?

 

[milldrone]

6 24vdc outs for valve solenoids.( i take it that dc will power the ac solenoids at .1 amp?)

I would suspect the AC solenoids will be a problem if you bare trying to energise them with a DC output.

 

[Eric Nelson]

I would suspect the AC solenoids will be a problem if you bare trying to energise them with a DC output.

I remember seeing coils on Festo valves that were rated for both AC and DC. The AC voltage rating was twice the DC, i.e 12VDC/24VAC. Not sure if they were special in any way.

That said, if Dan can't get 24VDC solenoids, he might 'try' running his 24VAC coils on 12VDC and see how much current they draw and how hot they get. I would agree that he should NOT run them on 24VDC.

Probably best to just use interposing relays. Automation Direct's little 5A card relays are a cheap solution...



-Eric

 

[todster]

I remember seeing coils on Festo valves that were rated for both AC and DC. The AC voltage rating was twice the DC, i.e 12VDC/24VAC. Not sure if they were special in any way.
-Eric

I think those had a diode in them. Sounds like Dans solenoid valves are for HVAC. Using them on DC will only produce that all to familiar acrid smell along with a possible mini mushroom cloud.
Maybe what you need isn't a "PLC". This might be worth looking into. http://cainetworks.com/products/webcontrol/webcontrol-faq.html
The outputs are TTL so you'll need relays to interpose.
It has 20 timers so you can set the date and times. Hook it up to a wireless AP and mount it in a watertight enclosure and you can access it from anywhere you have internet.
The boards are around $35 last I knew. These are used alot with the arduino components, etc.. It has analog inputs so you could put coils on the pump wires and monitor for high current conditions etc... The best part is no expensive software to buy and its network ready out of the box. http://www.ushomeautomation.com/Notes/WebControl/WebControl.html
http://ecorenovator.org/forum/appli...ontrol-universal-industrial-controller-2.html
Here you can see where some dude (apparently) named Andy, left his wide open. http://98.204.76.238/.

 

[danl]

look at my past posts

the solenoids i have to energize are all sprinkler valve solenoids. they are 24 ac and have a small inrush current and operating current to be concerned with. they are rainbird and orbit valves and very common. the two pumps i have to energize are 115 vac pumps. don't mind using relays or whatever to energize an outside power supply to do all of this. i just need guidance on what to pretty much buy to have all this work together. there are the need to be able to run 11 individual 24vac solenoids, two level sensors and two pumps. an example is: 7a.m.- pump 1 on. 4 solenoid feeds on. 1 distribution solenoid on. level indicator sees low water, turns pump 2 on. energizes solenoid feed on. sees high level turns off pump 2 and closes one solenoid off. finishes sprinkler mode (timer) turnes off 4 solenoid feeds and one distribution solenoid. keeps pump one running.
its simple as that.. but i don't know controllers or combination where in to get to power up this equipment. 24vac solenoids that have about 5 amps in rush and about 1 amp operating amp draw., two level switches., and two motor starter relays. that's about it.

 

[GlennA]

Are you familiar with relay logic ? Can you write out what you want to do in relay logic ? After you have it written out, you might find things you missed, or things you can combine; if the 4 solenoids and 1 distribution are always on at the same time, that might work with 1 plc relay output driving 5 relay coils. Or you might decide you want a separate output for each of those 5 valves.

 

[Lancie1]

The outputs (6) on the plc are strictly 24 vdc @ .1 amp per point. I'm not sure how this would handle an inrush at the valve solenoid though. Maybe another relay block?

NO! NO! NO! I will say it all again. You need to adjust your thinking about how PLCs work. I think you are under the impression that PLC outputs must be the same voltage as the power supply that operates the PLC. That is not true AT ALL. PLCs are made to be very flexible. In the case of the Click, the power that supplies the Click CPU power must be 24 VDC. But the power that supplies the relay outputs does not have to be 24 VDC. The outputs on the Click C0-01AR-D are NOT strictly 24 VDC. They are relays, so the output voltage can be nearly anything, AC from 6 to 264 volts AC, or even DC from 6 to 27 volts DC (see attached picture of the C0-01AR-D specifications).

http://www.automationdirect.com/adc...s_(Stackable_Micro_Brick)/PLC_Units/C0-01AR-D

1. Buy the Click C0-01AR-D.
2. Buy a 2-Amp, 24 volt DC power supply to run ONLY the Click CPU.
3. Buy a 120/24 VAC transformer to run your 24 VAC solenoids.
4. Buy two 7-Amp isolated relay modules to get your outputs up to the 12 that you need. You can run your two pumps and some of your 24 VAC solenoids from these add-on auxiliary modules.

Connect the 24 VDC power supply to your Click power terminals. That is the only place you need to use the 24 VDC power.

Connect the 24 VAC from your new transformer to one side of your Click relay contacts. Connect the other side of the relay contacts to your solenoids. Now when the Click program turns on the outputs, 24 VAC will flow to your 24 VAC solenoids.

Forget about using 24 VDC on your solenoids. You do not have to, so why would you? Like others said, that is a burn-out waiting to happen.

 

[danl]

oh dang. thanks lancie. i misread the specs. i thought the relays only had 4 outputs each and that i was going to have to use the plc's outputs ad well to make the combined number. i was thinking total 2 relay modules and plc module) as 14, only really requiring 12. my bad. sure do appreciate ya input here. it's helped me ALOT !. looks i'm now well on my way of getting this done now. thanks again!!

 

[Lancie1]

these are the items that just may do the trick.
plc- 1 click model co-01dd2-d. has a real time clock battery back-up memory, 8 dc 24vdc ins (for the level switches)and 6 24vdc outs for valve solenoids.

If you really want to use 24 VDC inputs, then look at the C0-01DR-D. It has 24 VDC inputs (that can be powered from your 24 VDC power supply that you have to buy anyway), but still has relay outputs that can be used with your 24 VAC to run your solenoids. You can use two of the outputs at 120 VAC to run your pumps (through external relays, or use two of the 7-Amp isolated relay module contacts).

http://www.automationdirect.com/adc...s_(Stackable_Micro_Brick)/PLC_Units/C0-01DR-D

 

[Lancie1]

I misread the specs. I thought the relays only had 4 outputs each and that I was going to have to use the plc's outputs as well to make the combined number.

Well you are still a little confused. A Click PLC only has 6 built-in outputs, period. You cannot stretch an output to make it into two. Outputs are costly and therefore valuable, so you must carefully design your system to eliminate outputs that you do not really need. The relay-output Click models have relay contacts rated for 1 Amp, with a 3-Amp maximum in-rush current for 10 miliseconds. That rating will probably handle your solenoid valves.

I was thinking total 2 relay modules and plc module as 14, only really requiring 12.

The only way to use a Click PLC and have 12 outputs is to buy some add-on auxililary modules. In your case, the most sensible one to buy is the 7-amp relay module, which does have 4 relay outputs per module. Therefore you need two of those, giving you 14 outputs and two spares that you may find a use for.
http://www.automationdirect.com/adc...cro_Brick)/AC_I-z-O_-a-_Relay_Outputs/C0-08TR

...the two pumps I have to energize are 115 vac pumps. I don't mind using relays or whatever to energize an outside power supply to do all of this.

Your wiring description is sort of backward. You do not need to use relays to energize an outside power supply. Instead, use a manual switch or switches to turn on a 24 volts DC power supply and a 120/24 Volts AC transformer. Wire the 24 VDC power supply to the Click relay-output PLC. Feed the 24 VAC to your PLC relay outputs (both the 6 internal relay outputs and the 8 external auxiliary module outputs). Use the PLC to turn on the relay outputs at the correct time, based on the internal Click PLC real-time clock.

Now, depending on how you are wiring your two 120-volt pumps, you might save $48 by buying one C0-08TR 8-relay 1-amp output module instead of two of the 7-Amp C0-04TRS modules. If your pumps can run directly off of the 7-Amp relay outputs (you never said how much starting current your pumps need), then use the C0-04TRS modules. Notice that each output of the C0-04TRS module can handle 4.9 Amps inductive current and 12 Amps of inrush current. That would start and run a 1/6 HP pump. If you pumps are larger, then you need external motor starters. Then use one C0-08TR auxiliary module, and buy two external 120 volt pump motor starters.