# 240V 30amp Mechanical Relays



## jlmcgrath (25/3/15)

Hey everyone,

In the gathering stages of putting a control panel together. Very similar to the Electric Brewery setup, but using a gas boil and no volt/amp meters.

I am having a really hard time finding panel mount 240v 30amp mechanical relays for the element switching. I see lots of people using Clion relays but can't seem to find any without having to order 200 of them, or paying $45 each for shipping.

Do I suck that badly at using google?

Anyone have any tips?

Cheers,

Jeff


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## dave81 (25/3/15)

Why do you need mechanical ones? I use solid state relays as do many people.such as this and it is controlled by my pid
http://m.ebay.com.au/itm/231296063774?nav=SEARCH


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## jlmcgrath (25/3/15)

I have SSR's to switch the elements on and off when the PID wants them to. I am looking for mechanical relays so I can use a switch to turn the elements off is I need to.


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## dave81 (25/3/15)

Just put a switch inline with the ssr trigger


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## krausenhaus (25/3/15)

This is what I have:

http://www.jaycar.com.au/Electromechanical-Components/Relays-%26-Accessories/Panel-Mount/240V-AC-Panel-Mount-Relay/p/SY4044

You don't need the big cube things that TEB uses.

I use it because I have a switch and indicator light that are rated for 10A while my element is 15A, so I can't have them in series with the element.


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## mofox1 (25/3/15)

Try looking for larger current switching relays... I ended up with 80A relays as they were available and reasonably priced.

First hit on aliexpress for me was us$28 for two, free postage. Searched for "80a relay" although often it helps to add the word coil.

No linky sorry, on phone. There was another one there for us$18 ea.


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## n87 (25/3/15)

http://au.element14.com/webapp/wcs/stores/servlet/Search?catalogId=15001&langId=43&storeId=10184&categoryId=800000004761&pageSize=25&showResults=true&pf=111783444,111783449,111783467,111783468,111783469,111783471,111783478,111783482,111783483,111783489,111783568,111783571,111783572,111783576,111783577

http://www.jaycar.com.au/Electromechanical-Components/Relays-%26-Accessories/Panel-Mount/24VDC-Panel-Mount-Relay/p/SY4041


i like the clicks of a mechanical relay


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## mofox1 (25/3/15)

n87 said:


> http://au.element14.com/webapp/wcs/stores/servlet/Search?catalogId=15001&langId=43&storeId=10184&categoryId=800000004761&pageSize=25&showResults=true&pf=111783444,111783449,111783467,111783468,111783469,111783471,111783478,111783482,111783483,111783489,111783568,111783571,111783572,111783576,111783577
> 
> http://www.jaycar.com.au/Electromechanical-Components/Relays-%26-Accessories/Panel-Mount/24VDC-Panel-Mount-Relay/p/SY4041
> 
> ...


The big ones go clunk.


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## Eagleburger (25/3/15)

Could use a low volt switch on the control side of the ssr.


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## dblunn (25/3/15)

If you are wanting to have electrical isolation then I would stick to the relay/switch on the downstream side of the SSR. Those SSR devices are more fragile than a relay and could fail at an inopportune time, even when working normally they have a small leakage current that may cause safety concerns.
Dave


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## jlmcgrath (25/3/15)

Wow! The difference in returned search results between 80 amp relay and 80a relay is crazy. Thanks for helping to learn the internets. 

Just to confirm my thoughts really quickly. I will have 2 feeds to my control panel. One 10A and the other 15A. 10A runs the HLT, 15A runs herms, electronics and pumps.

Control panel will have a master key switch. I would use 1 x DPDT relay for the incoming feeds, and a SPST for each of the elements?

Thanks again everyone.

Jeff


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## jonnir (25/3/15)

Throw some links up of the gear that your finding mate, may be able to help better


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## dave81 (25/3/15)

Would you need 2 dpdt for the feeds,1 for each? or instead of isolating the neutral aswell are you just going to use 1 leg for each active supply?


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## jlmcgrath (25/3/15)

Thanks for posting that Dave, it all just clicked. So I would need 4 DPDT total.


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## Camo6 (25/3/15)

Like Dave81 says you'd be better to use DPDT to isolate A&N to the elements. My main relay only isolates the active in but I would use DPDT's if I had to do it again.


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## Eagleburger (25/3/15)

I use ptp for isolation. Pull the plug.


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## MitchD (25/3/15)

So many experts so little good advice.


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## krausenhaus (25/3/15)

MitchD said:


> So many experts so little good advice.


You're an electrician, right? If you see bad electrical advice being given to a forum member then maybe you can chime in and contribute to someone's safety instead of just dropping a smug comment and moving on.


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## MitchD (26/3/15)

Perhaps all the non electricians could stop offering poor advice. 

The op hasnt posted any plans so I dont know what he plans to control and how. But I would never be wiring the neutral through a contactor.


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## dblunn (26/3/15)

MitchD said:


> But I would never be wiring the neutral through a contactor.


Normally yes but, as the final point of isolation before the element of a portable water heater that may well be supplied via an extension lead, I think a double pole switch/relay would be a good idea. 
Dave


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## dave81 (28/3/15)

Never the neutral alone of course but I dont see an issue in a douple pole isolation of the elements or the control panel supply


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