jld612 trouble

[jeremy]

im currently working on a thermal immersion circulator and am having a difficult time wiring it up. im using a ssr relay to control the heating coils so i dont burn out the internal relay, but again not sure how to wire it correctly. i think i need to use the internal relay (j2) to control the ssr relay, but if anyone can offer some suggestions or a possible diagram on how to wire, id really appriciate it. thanks for your time.

[Tech_Marco]

There is an output for the SSR from the 612 controller. Why would you use relay to control the SSR instead??
See page 7 of the manual, the Fig. 7 show #6,#7 is for the SSR output.

[websta]

I'm attempting pretty much the same thing with the JLD612 and SSR-25DA. As indicated, I have the SSR connected to terminals 6 & 7 and the thermocouple (PT100) connected to 8-10. PID seems to work as voltage on DC side of SSR is about 7.5 volts but there's no AC voltage on other side of SSR (red light is on). SSR is brand new - hope it's ok.

The JLD612 has a component (resistor or capacitor, can't tell) poking through the hole where terminal 11 should be. I can't tell if both ends are soldered as they should be but the PID seems to work. Is this normal? Can provide picture if need be.

UPDATE: Think I may have figured it out after doing more research here and in particular: viewtopic.php?f=5&t=320

I connected things as shown in the diagram (no fan or TX in my case) but there was no power to the PID. Is there supposed to be a connection from terminal 2 to the other side of the AC (blue line)? I tried it with terminal 2 connected to the AC and things seem to be working. In effect, terminals 1 & 2 of the PID are connected to terminals 1 & 2 of the SSR respectively - kinda makes sense.

[Tech_Marco]

Remember, a SSR(solid state relay) is just like a switch. You won't get AC output from a switch unless you send power from one side of the switch, and during closing circuit, current conducting to the other end. The DC signal signal can be "interpretable" as a button of the switch. You send signal to the input of the SSR (thining you're pressing the switch button), the normally opened circuit become a closed circuit and conducting current.

Unless you can send a diagram, I have no idea why it wont' work.

[websta]

Thanks for the reply Tech Marco - seemed to be working as it should so went through an Auto Tune. Came up to 140 degrees (target) and eventually finished tuning (AT light off). Unfortunately, temp kept dropping even though output was turning on and off. Cycled AC power to see if that would make a difference. At a 134 degrees I decided to try AT again so we'll see what happens. I documented PID settings from first Auto Tune so I'll see if round 2 is any different.

If temp keeps dropping after second AT, I'll provide a diagram.

Thanks again for the help.

UPDATE: second Auto Tune completed and then dropped to 137 degrees (from 140). After a while it climbed back to 140 and it's been there about 45 min. Looks like there may be some initial settling in after doing an Auto Tune.