control pannel help

[Cain Harland]

I just wired up my little RIMS tube control panel and somethings freeking me out. I have an indicator light hooked up to the neural and phase terminals of the element socket. So basically it runs in parallel with the element. The relay has a built in indicator light to show signal from the PID and its working as I expected (only on when switch is on and PV below SV) but my one is always on which I don't get as I only expect the phase side to have power when the relay is being activated. The switch just interrupts the signal from the PID to the relay so I can turn the element off but keep the PID on. There is also a regular 10amp outlet on the side for my pump.

The wiring seemed real simple to me the neutral and earth terminals on the 30 amp (element) socket are connected appropriate input and the same terminals on the PID and 10 amp (pump) socket. With phase the input for the Relay is connected to the phase in and phase on the PID and 10 amp socket and the relay output is the only thing connected to the phase on the 30 amp socket and light. Now I don't want to plug in the element in  until I know its going to turn off when its supposed to.

I have 3 possible reasons for my problem

1) I wired it wrong

2) The SSR is poked and always on

3) SSRs allow a little power through even when off and its enough to run the light but not the elememt or require more resistance than the lights providing to operate correctly

Can anyone shed some light on this for me.

[Cain Harland]

Before someone comments on the 1.5mm wire and 30 amp socket, I'm not running a 30 amp element just wanted the pump and element sockets to be incompatible. The element is 3000kw so I will be drawing 12-13 amp all up.

[Smiffy]

See if you can find a data sheet for the exact SSR you have, and look for a figure which tells you what the resistance should be across the AC terminals when it is powered off, then you can measure your SSR.

You don't say what the indicator lamp is, if it's a LED, they will light up with a very high resistance in the supply, but once the real load is connected it wouldn't.

Smiffy

[Cain Harland]

I don't know what it is. Its some cheap Chinese component that described itself as indicator lamp so possibly LED possibly a tiny bulb in there.

I guess I will just give it a test run with the element.

[Chris Banks]

Def no3 - they pass a small current when off

[Cain Harland]

Thanks thats made me feel better about giving it a go with the element.

[Cain Harland]

Running it with the element sorted it all out. Factory settings on the PID ended in a 6 degree over shoot but auto tune reduced that to 2 while tuning. So hopefully better after tuning and on bigger volume of water, test was only about 6L. Next test with sugar syrup because I'm a little worried about scorching due to limited flow in the pipe fitting I used for an element adapter so I could use a 1.25 inch BSP element rather than importing something.The 10 amp components all handled the 3kw load no problems nothing even got particularly warm other than the RIMS tube itself.

[Barry]

Yep, that's why a lot of e-brewery builds also feature a mechanical relay as well as the SSR, so you switch it off and be sure of full isolation.

[Cain Harland]

Maybe I will rewire so the switch is between the relay and element socket instead of PID and relay. Although its probably not the same kind of issue on my little control panel that only controls one element as it might be if you were controlling 2 or 3, I'm not for example going to have and empty kettle sitting there with an element I don't want to fire at all.

[Barry]

yeah horses for courses, for my system it's peace of mind that if the switch is off I can clean/move my pots knowing there's zero current running through the element.

[Huntsman Brewing]

Check the link below on the Fotek SSR. It seems there are some dodgy knock offs appearing on the market. I'm not saying yours is, or this is your problem, but wouldn't hurt to check

http://aussiehomebrewer.com/topic/90323-counterfeit-ssr-warning-che...

[Cain Harland]

Thanks for the heads up. I will keep an eye on it but all seemed to be running fine during test with element and I'm only putting about 12 amp through it so maybe the fake one (it almost certainly is fake for < $5 on aliexpress) will handle the load.