pool controller - Page 1
Forum section: electronics / general

author: foremancr
author_rank: Newbie
timestamp: July 27, 2020, 07:18:06 pm
content: I am very much of a beginner. I am a engineer but I was working in this trade years back. Now I am retired. I have a pool controller that is very old and the main controller board no longer works. I would like to design and build a new one. The controller must turn the pump on ( 2 hp 220 vac) and provide voltage for (2) 24v valves, turn on a electric heater (24v), turn on a 120volt blower fan for the spa and supply 24v to a salt water chlorinate. I have a pool pilot that will monitor the chlorine levels of the salt water chlorinate. I need it to be remote controlled, not necessary to be cell phone controlled.

author: ebastler
author_rank: Super Contributor
timestamp: July 29, 2020, 06:22:24 am
content: Hi foremancr, and welcome to the forum!You don't really state your question -- what are you looking for?Also, you have posted this in the "KiCAD" section of the forum, where the functionality of one specific software tool for schematic and layout design is discussed. But it sounds like you are more interested in advice on how to approach the circuit design in general. I would recommend posting your (clarified) question in the "Projects" or "Beginner" section of the forum; that should result in better feedback.

author: Ian.M
author_rank: Super Contributor
timestamp: July 30, 2020, 06:52:33 am
content: You can move this topic to a more appropriate forum. Seehttps://www.eevblog.com/forum/blog/what_s-this-move-topic-icon-all-about/So you've got various pumps, valves and other loads that need to be controlled in sequence, presumably with some sensors, manual controls etc. that trigger various actions.There are various ways of tackling this, depending on your expertise familiarity with industrial control systems and embedded systems.The low hanging fruit, and probably the cheapest in terms of performance and satisfaction divided by time and cost, is to get an off the shelf pool control system and install it, keeping as many of your existing loads as possible, but replacing any that cause compatibility issues that cant be solved with a simple solid state relay.Then there are various options based on wiring together off the shelf parts, mostly intended for industrial control applications. Take a hint from the Europeans here and get modules that fit a DIN rail mounting system and put a DIN rail in your enclosure, as then (most of) the various modules you need can just 'click' into place,then wire point point. You can get DIN rail mount relays, SSRs, circuit breakers and GFCIs, and even small power supplies. You'll also need something to be the 'brains' of the system. The easiest option here would be a small industrial PLC, but other options would be something Arduinoish, either with a PLC shield or with built in PLC style protected inputs and outputs, or a fully custom logic board of your own design. The major advantage of this sort of modular approach is that mains and high current low voltage circuits only go through off-the-shelf modules with safety approvals, and all wiring can be done in compliance with your local electrical code.Then there's the fully custom approach of designing a replacement board to retrofit your old controller with, or possibly to standalone in a new enclosure, duplicating and possibly extending the old controller's functionality. However the old controller probably failed for a reason, and if it was corrosion related, its highly probable its due to moisture ingress and the old enclosure is compromised beyond economic repair.In all cases you are going to have to maintain a non-condensing humidity level inside the new controller's enclosure. As its totally impractical to hermetically seal an enclosure of significant volume that is exposed to a wide temperature range, you will need some sort of pressure equalisation vent system that either does not permit moisture ingress (e.g vented to an internal bladder, + a desiccant cartridge in the main enclosure volume), or has provision to monitor the internal conditions and heat the enclosure as required to keep its interior above the dew point.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 04, 2020, 09:13:57 am
content: Be careful with what you build.I've heard someone who did this and due to a software glitch or hardware short it dumped all the chemicals in the pool, and apparently that stuff is a bit pricey.