which manufacturer/model PLC easy to use/accessible for home installations - Page 1
Forum section: electronics / beginners

author: V_King
author_rank: Regular Contributor
timestamp: April 19, 2018, 01:43:20 pm
content: Hello,I am setting up a small PV solar setup for my boat and would like add some logic control to prevent my batteries going below 50% depth of discharge. Pretty much I just need an industrial grade voltage comparator, which would flick a high current changeover relay between inverter power and shore power hookup depending on the battery bank voltage.I am trying to use industrial din rail mount controls everywhere as the installation and maintenance is usually easy, robust and straight forward. I do not want to faf around with arduino type setup for the control, so think a simple PLC controller would suffice.Does anybody work with various PLCs and could recommend which one to go for, which is:1. cheap (especially could be found easily second hand on ebay)2. does not need any paid for software to configure it.I know there are arduino PLCs but they seem to be in a region of >£200 which is above to what I'm happy to pay.On the other hand, I understand I could mock up some op'amp with adjustable voltage regulator to work as comparator, which is straight forward. What is not straight forward is making sure it is safe (inputs, outputs, fire, etc), so probably a well designed PLC is again a better choice.Unless there are din mounted voltage comparators I am not aware of?Other suggestions are more than welcome as well.Cheers

author: TopLoser
author_rank: Unknown
timestamp: April 19, 2018, 02:15:40 pm
content: Well the Siemens Logo PLC's are readily available and have analog inputs. I always seem to have a pile of them left over at the end of jobs...Software is officially £45 but you can get it for free if you look around.You can get USB programming cables for $25 on eBay or buy official ones for stupid money.

author: Bratster
author_rank: Frequent Contributor
timestamp: April 20, 2018, 06:57:56 am
content: Automation direct has pretty good prices for plcs, their programming software is also free.https://www.automationdirect.com/adc/Overview/Catalog/Programmable_ControllersI haven't used their stuff yet, but it's the first thing on my list for when I do need a PLC for a project.Sent from my Moto x4 using Tapatalk

author: V_King
author_rank: Regular Contributor
timestamp: April 20, 2018, 07:16:19 am
content: Thanks for the replies. Trying to get my head around the Siemens Logo range and understand it's capabilities/limitations.TopLoser, a question for you in regards of wiring everything up. How do you do the power distribution for relays etc.? I have 24V din mount PSU, which feed relays, other controls and it only has 2 outputs. Are there any mounting distribution blocks or something to make all the wiring neat?Thanks,

author: lypse
author_rank: Contributor
timestamp: April 20, 2018, 07:30:20 am
content: A normal home should not need PLCs, since most of people will not know how to adjust anything later on (eg. next home owner or electrician), or the software/parts are obsolete or extremely expensive.I think that is the main reasons to why the home automation stuff has never taken off.. not to mention the increased cost when building a new house.Also remember all the space and cables needed when you start running a line to each switch/outlet ect.. it adds alot materials and labour....I have purchased a micrologicx 1100, but but only because I got it cheaply with a handfull of I/O modulesI don't think I will re-wire my house to run on software anytime soon..

author: lypse
author_rank: Contributor
timestamp: April 20, 2018, 07:41:54 am
content: Power distribution for the relays are no different than what you already do. except the relay will have a max load it can switch/carry."mounting distribution blocks" I believe you are looking for DIN terminal blocks, they come in endless variates.

author: TopLoser
author_rank: Unknown
timestamp: April 20, 2018, 09:49:21 am
content: http://uk.farnell.com/phoenix-contact/3044076/terminal-block-din-rail-2pos-12awg/dp/8332975Loads of variations and accessories for this kind of thing.

author: cs.dk
author_rank: Unknown
timestamp: April 21, 2018, 05:28:16 am
content: Quote from: TopLoser on April 19, 2018, 02:15:40 pmIf you wan't to rid of some, then send a PM. Could use an extra or two.Quote from: TopLoser on April 19, 2018, 02:15:40 pmLOGO! is programmable via ethernet. No need to buy utterly expensive cables.

author: TopLoser
author_rank: Unknown
timestamp: April 21, 2018, 05:02:27 pm
content: Quote from: cs.dk on April 21, 2018, 05:28:16 amYes you're right, the new Logo!8 series all have ethernet, but not the old series stuff that you'll probably get cheap on eBay.OP could probably program his application via the front keypad, application sounds very simple. No software or cable needed at all.

author: gocemk
author_rank: Regular Contributor
timestamp: April 21, 2018, 05:24:47 pm
content: I strongly recommend Unitronics PLC's for this kind of stuff. Every model comes with some sort of HMI (2x16LCD on the cheapest Jazz model, and color TFT on the better models).They are extremely reliable and i use them both in residential and industrial environments and they have never failed me.The software is free and you can download it from their website. The cheapest Jazz models can be programmed via cheap RS232 converter cable, while the later models are programmable via USB.Their website ishttps://unitronicsplc.com/Also, you can find plenty second hand models on ebay.Hope this helps.

author: V_King
author_rank: Regular Contributor
timestamp: April 24, 2018, 07:25:18 am
content: Thanks for all the answers. Seimens logo looks like a good place to start and ticks all the boxesgocemk, thanks for the suggestion, but it seems there are three reasons not to use unitronics. I can't find any on any of the ebay websites accessible to me, their prices seem high and the third one is not the place to be discussed here.

author: Jeroen3
author_rank: Super Contributor
timestamp: April 24, 2018, 07:54:23 am
content: You can also try CLICK PLC or Wago 750. Perhaps Eaton Easy, but these are expensive.