Swa-2441 pid

I've looked through the posts and cannot find any information here on anyone using the Auber SWA2441 PID.
I've been given a couple of them and wondered if they'll work for a control panel or if they're junk for brewing.
Thanks.

Unfortunately, the SWA-2441 only has relay outputs, so is not suitable for driving an SSR (http://auberins.com/images/Manual/SWA-24x1 v1.pdf.) The SWA-2451 does have voltage pulse outputs for driving an SSR.

Brew on

But despite that, you might still be able to find a use for them. Maybe as readouts for temperature sensors that don't control anything, or to control something that doesn't switch often (bringing a HLT up to temperature - set up the PID parameters so they just work as a thermostat, and use a DC supply to give the SSR control voltage?).

Rats!
Thanks doug293cz and dyqik

The relay inside is usually driven by a 5 volt pulse. I removed the relay on one I have and jumpered the output to drive a solid state relay. Worked great.

Could I use the timer function from these on a PID(2352) that might need an external timer?

MacAle,
Do you have a diagram of that mod?

http://diyourself.ru/food/electric-brewery-control-panel-on-the-cheap-do-it.html

Check out this url and it explains what is going on.

I looked for a schematic for that PID but didn't find one on their web site.

Thanks MacAle.

DNKDUKE said:

Could I use the timer function from these on a PID(2352) that might need an external timer?

Click to expand...

I guess you could wire the SSR output of another PID through the relay and use the timer feature to cut off the control signal when required.

One last question...
What is the difference/benefits between an SSR and a contactor?

DNKDUKE said:

One last question...
What is the difference/benefits between an SSR and a contactor?

Click to expand...

A contactor is an electro-mechanical relay ideally suited for switching high currents/voltages at low rates. Switching contactors at high rates will lead to early failure. Contactors have zero leakage when off, so are good for providing safety isolation of high voltages. Contactors have very little internal resistance, so generate almost no heat in use. Thus they do not require heat sinks or special cooling.

An SSR is a completely electronic switch ideally suited for switching high currents/voltages at high rates. Since there are no mechanical components to wear, or contacts to degrade due to arcing, they can switch millions of times. SSR's have significant leakage (mA) when off, so they are not effective at truly isolating high voltages for safety purposes. SSR's also have significant internal resistance, so generate heat when conducting high currents. Thus they require heat sinks to keep them from overheating. Running an SSR too hot will reduce its life.

Brew on

Thanks.
Seems to me that both would work but the controller would not be as effective.

Best practice is to use both. A PID controls an SSR with one hot leg running through it. Both hot legs run through a DPST, NO contactor activated by a switch. For the element to fire the switch must be turned on to close the contactor and the PID must be signaling the SSR to close. Since SSRs leak current and can fail closed, this is a way to know that "Off means off."

jeff...
Understood and agree but I'm talking about a PID that won't work with an SSR but only a controller.

jeffmeh said:

Best practice is to use both. A PID controls an SSR with one hot leg running through it. Both hot legs run through a DPST, NO contactor activated by a switch. For the element to fire the switch must be turned on to close the contactor and the PID must be signaling the SSR to close. Since SSRs leak current and can fail closed, this is a way to no that "Off means off."

Click to expand...

+1 (except ' this is a way to no that "Off means off." ' should be ' this is a way to know that "Off means off." ') Sorry to pick on your typo, but this point is important enough that there should be no risk of misunderstanding.

Brew on

DNKDUKE said:

jeff...
Understood and agree but I'm talking about a PID that won't work with an SSR but only a controller.

Click to expand...

Are you trying to justify having a marginal design to save $50 on a $500 plus system? A contactor will have a short life used with a cycle time suitable for electric brewing. A longer cycle time may lead to temperature instability or scorching (depending on your element watt density.) Use an SSR to control the element. If you want to use the PID in hand, then tap into the PID's relay control signal to drive the SSR (earlier post in thread showed or linked to how to do it.)

Brew on

Agree 100%
Sometimes people need to talk things out outloud with people who've been there. Ya'll have been very helpful.
Thank you.

doug293cz said:

+1 (except ' this is a way to no that "Off means off." ' should be ' this is a way to know that "Off means off." ') Sorry to pick on your typo, but this point is important enough that there should be no risk of misunderstanding.

Brew on

Click to expand...

No apologies necessary. Edited accordingly.

Check it out, you can turn a 2441 into a 2451.
http://www.auberins.com/forum/viewtopic.php?f=2&t=1386&sid=0d14d7f29c1606a62dbc0983ae7b094a