PID Confusion

[MankySteve]

I've been looking at PID on the bay and such and there such a range especially the bay. It got me al confused.

 

[keith1664]

My tip is to make sure that whatever you buy works with the type of probe you'll be using. The really cheap PIDS tend to only work with K type thermocouples, look around the £20-25 mark for those that work with a range of probes, especially PT100 probes.

 

[Northern Brewer]

These are reprogrammable to work with K and PT100 amongst others, only just over a tenner too. Had no problems with delivery either.

I've tested this with these probes and these SSRs

I believe SSRs can be switched AC or DC, the PIDs above send out 12V DC (don't need a seperate supply) to switch the relay.

Cheers
NB

 

[keith1664]

How do you go about reprogramming them? I have one I bought by mistake!

 

[Vossy1]

This PID controller from Auberins is a winner, used by many of us :thumb:

 

[Northern Brewer]

How do you go about reprogramming them? I have one I bought by mistake!

Depends which one you get, mines Rex C100 and the instructions came with it,

 

[Northern Brewer]

anybody tried one PID driving two SSRs?
I have two seperate 15A feeds and may want an SSR on each - not worked this through yet but just thought I would ask so I have th eoption, I may give it a go later.

Cheers
NB

 

[Darcey]

I bought 2x PID's that are useless to me. 12V and 48V bugger.

 

[keith1664]

I have my pid quite happily running 2 ssr's. Just connect them in parallel.

 

[Northern Brewer]

I have my pid quite happily running 2 ssr's. Just connect them in parallel.

Thanks Keith :thumb:

 

[Northern Brewer]

I bought 2x PID's that are useless to me. 12V and 48V bugger.

why useless? are your SSRs AC switched?

 

[Darcey]

I am struggling to find information about them as they are from ebay and several of the shops I purchased them from (China and HongKong) are no longer active on ebay .

Unless I am being a fool. If the PID says Power

Supply 12V DC

but output mode

Relay Contact: 3A at 250VAC, SSR: 8V DC, 30

can I plug the PID in to the mains?!
The other has a smilar but with Power Supply 48V DC... :cry:

 

[Northern Brewer]

If you post some photos showing the connections, any labelling and model number of the PID and SSR then may be able to help, or somebody else may recognise them.

 

[timbim]

can I plug the PID in to the mains?!
The other has a smilar but with Power Supply 48V DC... :cry:

It needs a 12V supply from somewhere, butchering an old wall wart is the cheapest, but a decent switchmode 12V isn't going to be expensive either.

The best way to find out if you can run an SSR off it would be to meter the output terminals with a voltmeter. If it's spitting out anything above 3V, then you can drive an SSR directly. Pay attention to the maximum voltage the SSR is rated for and make sure the output doesn't exceed that. Also make sure that the SSR you buy is rated for an AC, 250V load or it will explode.

If it doesn't supply a voltage directly, it will almost certainly just be closing a relay between the two output terminals. Check that with a meter in the resistance mode. If that's the case, you can take the 12V supply and feed it into one side of the output, take the other side to the + terminal of the SSR, and the - terminal to the - terminal of the supply. Of course if the SSR doesn't have polarity marked, it doesn't matter which way round you put it.

It's likely that the other will run happily on a lower voltage supply, try it on 12v and see what happens! The worst that could happen is it not working.