[FIXED] Electric Brewery Problem - Elements won't work

[och29]

Hi,
I've slowly been building my new electric brewery clone (see here) but can't get my elements to work. I'm using a HERMS setup so there's an extra PID, SSR and relay. Here's what I've got at the moment (I've omitted the wiring from the switch to the relay coil):



The output light on the PID goes on, the light on the SSR lights and the relay makes a click when I turn the switch. I measured 240V across the SSRs when the switches is on... can anyone tell me why the elements aren't working?

Thanks, och29

[bobsbeer]

Is the relay coming on after the SSR?

[Fil]

just a couple of things?

1) Pids are bundled with SSRs to cater for the high frequency switching which would kill a mechanical relay rapidly, so putting a mechanical relay at the end of the pid ssr coil relay control chain is puzzeling me?

Secondly, unless its been ommited for clarity reasons the schematic dosent appear to have any load feed to the mechanical relays just a switching current fed from the ssr?

without a load to switch the elements wont have any chance of working?

[Belter]

This is the problem with the American Electric brewery website. The mechanical relay is entirely pointless. You only need to isolate the line conductor in your circuits but in America you have two line conductors. SSR's are single pole so you need another double pole relay to isolate the other conductor. In the UK the neutral can go to the element and the line conductor only isolated by the SSR. I haven't actually looked at your problem yet so that may not help just wanted to clarify. It's easy for me as I'm an electrician but I avoided the electric brewery website like the plague to avoid things like that and designed mine myself. I'm sure others would disagree with me as at least the website enables people who don't know what they're doing to build an awesome panel for their brewery.


Any chance you could draw in the bit you've omitted as As far as I can see that should pretty much be the only place where the problem could be. Unless you've used the Normally closed terminal instead of the normally open terminal on the relay. Do you have 240v on the other side of the relay contact?

[och29]

As I understand it the mechanical relay is just a safety feature. The part I've omitted is a switch that activates the coil in the mechanical relay. When that switch is closed the coil activates and closes the mechanical relay. Unless this is closed, the SSR can activate but since there is a gap across the element it will not fire. Effectively its a safety isolator to prevent the PID/SSR activating the element unless you have selected the element using a switch.

The part I have omitted is just HOT BUS --> element select switch --> relay coil --> NEUTRAL BUS. There's 240V across the coil and an audible click when I turn the element select switch on so I don't that's the problem.

Between JBK and The Electric Brewery Forum I think it's either a problem with the connections on the relay (i.e. doesn't allow current to flow through it to the element) or the neutral return from the element. If it is a neutral return problem could just wire from the element neutral back to the neutral bus?

[Fil]

Ahh, test the element with a multimeter set to read resistance, if ok the element will conduct when you touch meter probes to each element pole. if no conductivity the element is the weak link

[och29]

I'm using a Magnecraft 92S11A22D-240A mechanical relay, below are the pin connections.



The element is connected between 8 and 4. Power from the SSR comes in to 6. Pin 2 on all four relays (including the main power relay) are connected together and connected to the neutral bus.

[Belter]

Yes you could. I take it you have a volt meter? This should be a very easy fix. Check 240v between line and neutral bus on common of relay. Check on N/O terminal of relay. Check at element. Wherever you dont have 240 (which I'm guessing will be at the relay contact) is where the problem is. It sounds like you either have used the N/C contact on the relay which is going N/O when energised or have used N/O on line and N/C on neutral?

One thing to consider is that a SSR will leak voltage even when closed. Enough to fire a Neon. I don't know if it's enough to fire a relay coil but if it is then the PiD may be inactive and the mains firing the relay but you don't have enough oomf to fire the element.

[Belter]

I'm using a Magnecraft 92S11A22D-240A mechanical relay, below are the pin connections.



The element is connected between 8 and 4. Power from the SSR comes in to 6. Pin 2 on all four relays (including the main power relay) are connected together and connected to the neutral bus.

8 & 4 are technically the Common and the line and neutral should be connected to those but that won't be the problem.

Fil has made a good point. Check the resistance of the element to check it isn't faulty.

[och29]

My multimeter is a bit dodgey but they seem to be fine (when checked with a multimeter). The elements for the boil and HLT were bought from The Electric Brewery and the HERMS is a stainless kettle element from eBay. Given that I have two different types and two elements of the same type from the same supplier I doubt they are the problem but it was worth investigating. I've tried switching 6 and 8/2 and 4 but it made no difference. I've wired it that way for logistic reasons.
If I have used the NC contacts and common on the relay wouldn't that just mean that the switch works in the wrong way i.e. energizing the coil isolates the element? I'll go and have another look with the multimeter.

[Belter]

If you'd put your L&N on 6&2 and the switched connections on the N/C contacts then they'd never fire as you haven't used the correct common terminals.

[Belter]

Without a multimeter you're basically stabbing in the dark. Perhaps knock on Jim and Silvia next door and ask if they have one you could borrow?

[och29]

For clarification I do have a multimeter. I've changed the connections to the relay over but no effect -

Connected live(from SSR) to 8 and neutral to 4 (neutrals connected together across all 4 relays and back to neutral bus where neutral 'in' is connected) Element connected between 6 and 2. I could still measure 240V across the SSR terminals when the element select switch was selected on. When it was selected off (but the PID was still activating the SSR) I measured 1-2V occasionally which I assume is the normal leak you get with SSRs.

As there is obviously power coming to the SSR is it most likely to be the neutral connection? Shall I try wiring directly from the output plug for the element to the neutral bus?

[Belter]

Yes definitely.

You said you had a multimeter but it wasn't very good.

I'd bypass the second relay entirely

[Belter]

Have you checked for voltage on each side of the relay contacts and at the element?