# 240 Volt Relay



## wakk44 (Jun 15, 2006)

Can anyone tell me where I can source a relay with the following specs..

● 240 volt coil

● 2 sets of N/O contacts rated at 20A(15A at a push) 

Anyone got one knocking around in the garage ?


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## ched999uk (Jan 31, 2011)

Maplin, RS, Farnell?


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## bigfoot (May 16, 2005)

Does it have to be 240 operation as well as switching?
A mains relay will be rather big!
If you can use 12v to operate you can source a relay with 240v tungsten contacts.

It may make the search easier


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## wakk44 (Jun 15, 2006)

bigfoot said:


> Does it have to be 240 operation as well as switching?...............


Yes it has to be 240 volt operation as well as switching,somebody must have one somewhere.


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## bigfrank3 (Mar 26, 2007)

Important, I know you want a 240 volt AC coil but are you switching AC or DC through the contacts,it will make a big difference to the answer.

Frank


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## wakk44 (Jun 15, 2006)

bigfrank3 said:


> Important, I know you want a 240 volt AC coil but are you switching AC or DC through the contacts,it will make a big difference to the answer.
> 
> Frank


Hi Frank,

I want to put 240 AC through the contacts which have to be rated at a minimum of 15A preferably 20A.I think I may have to look at a contactor that is used in some industrial applications.


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## bigfrank3 (Mar 26, 2007)

A contactor would be your easiest bet, as most relays only handle up to 10 amps, unless you get a 4 pole relay and parallel them up to double the curent carrying capacity.

Frank


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## Murano (Mar 22, 2006)

Steve

Try two of these. Instead of connecting the contacts in parallel, connect two with the coils in parallel.
Hopefully 16a would be ok for the job in hand.

http://www.rapidonline.com/Electron...-60-1080/?source=googleps&utm_source=googleps

Dave


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## bigfrank3 (Mar 26, 2007)

Hi again Steve, 
The only problem with the relay that Dave suggests is that it is designed to fit on a PCB, although it is possible to get a mounting base. If you try to solder directly to the pins the cable is liable to bend and then break the pins. Tape or ty-wrap around the relay to hold them.

Frank


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## Techno100 (May 8, 2010)

The contactor used in Clive Mott's auto inverter blog has 2 n/o & 2 n/c ,I paid about £16 from scattergood & johnsons


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## DABurleigh (May 9, 2005)

http://tinyurl.com/7bbfhxr

Dave


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## Techno100 (May 8, 2010)

Just a note, the quoted spec on RS of 10 amp is wrong and this is a 16 amp contactor


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## wakk44 (Jun 15, 2006)

Thanks everyone for their help,I eventually sourced a relay after recommendations on this thread from RS Components

They have a branch in Nottingham so I called in and spoke to one of their advisers who was very helpful.After looking at 3 or 4 relays on the desk I settled on one with 2 n/o and 2 n/c contacts rated at 20A.It was just over £15.

I would recommend the above company for any electrical parts or specialised equipment,even though they normally supply to the electronics industry,nothing was too much trouble even for a small order like this.


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## Techno100 (May 8, 2010)

What's the part number Steve?


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## wakk44 (Jun 15, 2006)

Techno100 said:


> What's the part number Steve?


Hi Andy,

I have just got the part no. from the invoice and entered it into the RS search box and it comes up with this

Relay

However this is not the exact relay that I bought,it is almost identical apart from the number of pins.Mine has 6 which are 2 for the relay coil,2 n/c,and 2 n/o.The one in the link only has 4 pins. :?

I am sure if you wanted one a call to RS would clarify matters.


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## Techno100 (May 8, 2010)

I'm guessing you mean 8 pins?
2 for coil
2n/c
2n/o
2 common

http://uk.rs-online.com/web/p/general-purpose-relay/4927202/?

Potentially a candidate to use instead of the contactor. The contactor has the problem of the hum which becomes clearly audible late at night as the background noise dies down


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## wakk44 (Jun 15, 2006)

Techno100 said:


> I'm guessing you mean 8 pins?


You are on the ball this morning and have just won the prize for spotting the deliberate mistake. :lol:

Yes I did mean 8 pins


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## Techno100 (May 8, 2010)

How has the relay performed Steve?


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## Techno100 (May 8, 2010)

I'll let you know how it fairs as a changeover :thumbup:
Seems fine off hookup i.e. N/C


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## Pudsey_Bear (Sep 25, 2008)

Interesting thread  wtf are you making, as it's all foreign to me but sounds like something to do with EHU at a guess, me being a pro sparky NOT.


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## clive1821 (Mar 27, 2010)

Kev_n_Liz said:


> Interesting thread  wtf are you making, as it's all foreign to me but sounds like something to do with EHU at a guess, me being a pro sparky NOT.


I think you will find its auto switching from EHU to inverter output.... allowing you to use the same mains sockets.... thats my punt.... :wink:


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## Techno100 (May 8, 2010)

Yes Steve's search for a relay got me thinking of trialing it for an auto changeover as Clive sez.
I had originally copied Clive Mott's excellent project with a contactor but this unfortunately has an annoying hum in the quiet hours. The relay ought to be silent.


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## Waggys (Jul 15, 2008)

Hi,

I was able to remove the hum by wiring it up differently to Clive's system. I connected the Inverter to N/O connections and EHU to the N/C connections, that way the EHU was not operating the coil so the hum was not being produced. We do not use the inverter that often and the hum is a reminder that it is switched on......is it using some power to close the coil?? properly but not a lot and as we have forked out the money and time for the kit we have found this to be a good compromise!!

Waggys


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## Techno100 (May 8, 2010)

I'll be testing this on mains next weekend at Rawson Garth CL


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## Techno100 (May 8, 2010)

Well I'm happy to report that this silent relay is doing the job perfect within the bounds of a 350 watt inverter. :thumbup:

Posting on free wifi with a solwise on the list here
http://www.broadbandbuyer.co.uk/Shop/ShopSearch.asp?CategoryID=79


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## Techno100 (May 8, 2010)

This RS alternative would appear to offer the same but even cheaper
http://docs-europe.electrocomponents.com/webdocs/0514/0900766b8051459d.pdf


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## Techno100 (May 8, 2010)

UPDATE

These are the two relay options and the cheaper one on the right is Italian manufactured and a higher NC contact rating of 10 amps with 30 amp rating across the NO contacts. This will be adopted by me with a larger inverter to supply the kitchen skt/microwave
The other on the left is Chinese origin and is still working silently supplying my entertainment skts via 350 watt inverter . This for some reason is 3amp and 30amp relevant to the Italian item
Pictured below with RS stock numbers


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## Techno100 (May 8, 2010)

http://www.motorhomefacts.com/ftopicp-1309202.html#1309202


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