240v AC relay problems

Discussion in 'The Projects Forum' started by Beeches, Feb 18, 2012.

  1. Beeches

    Thread Starter New Member

    Feb 18, 2012
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    0
    Relay problem.
    All 240v AC items. I am adding an additional motorised valve to a central heating system which is an S plan with 2 on/off motorised valves. Everyone tells me this is simple and needs no relays, etc, but as soon as my newly connected motorised valve puts 240 volts into it's orange output cable, which I have connected to the boiler terminal block, the mains circuit breaker trips.
    So I bought 2 relays. An industry standard 8 pin octagonal base. I have everything working on a rig on the kitchen table, except that as soon as I put 240v on the output of the relay with the relay coil energised, it trips the mains.
    I need these 2 relays to stop the 240v boiler supply feeding into the other motorised valve, (or valves) which are 20metres away, even if the other relay is already energised. With the relay not energised the 240 volt from the other motorised valve(s) is effectively stopped from fouling things up.

    Relay pins are 2 and 7 coil (wired as switched live and neutral), 1 and 8 power supply (wired as permanent live and neutral), 3 and 6 are normally open contacts (wired as output live and neutral), 4 and 5 normally closed contacts. Not used at present.

    What am I doing wrong, or have I bought the wrong equipment? What I really need is a device which permits 240v AC to flow in one direction only.

    Any help would be gratefully received

    Beeches.
     
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    Can you post a schematic of what you are trying to build? Boiler connection terminal description and valve and relay model numbers.

    You apparently have the relays connected in the wrong way, so they make a short circuit on mains.
     
  3. Beeches

    Thread Starter New Member

    Feb 18, 2012
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    I will try to explain in more detail.

    The airing cupboard which contains the 2 existing 2 port motorised valves(Honeywell V4043 I think) and the circulating pump and all associated wiring, is 20m away from the boiler and my new Horstman motorised valve (equivalent to the Honeywell and an industry standard)

    Connecting the pump and boiler over this 20 metres is a normal domestic twin and earth cable, live, neutral and earth, which carries power from the pump. It is either on or off. Inside the boiler is a straight forward L, N & E terminal block. Actually the L is a switched live from the pump.

    I am told, with lots of manufacturers drawings confirming, that my new motorised valve orange output connection can just be added to the existing ones in the airing cupboard. But my new valve is 20metres away, and at the moment I do not have a cable I can use covering this 20 metres. So I don't know if this works, as I haven't tested this yet.

    I thought I could get away with just connecting my new motorised valve orange output to the L terminal in the boiler, but this obviously upsets something, and installing a relay was suggested by Horstman.

    I am ssuming, like you, that I have the relay connections wrong. Can you see anything obvious?

    Thank you for your interest.

    Beeches
     
  4. Beeches

    Thread Starter New Member

    Feb 18, 2012
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    Sorry, forgot to tell you. The relay is a DPDT 240v AC power relay from Maplins. Their number JG60. I realise I probably only need a SPDT, but I have used this type pf relay before, and forgotten all I knew. Brilliant!

    Beeches.
     
  5. hwy101

    Active Member

    May 23, 2009
    91
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    We can't see anything.
    Can you at least post a drawing of your your connections?
     
  6. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    So from what I understand you have an additional valve that you want to connect to this existing circuit.
    [​IMG]
    You tried to put the valve in parallel with the other which didn't work. You tried to connect it via a relay somehow which also didn't work. In the above circuit the two orange wires of the two valves are in parallel so why would an additional one not work (in parallel)?
    What is the new valve model #? Horstman something...
     
  7. Beeches

    Thread Starter New Member

    Feb 18, 2012
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    0
    Thanks for the drawings which I have seen before. If you look up Honeywell S plan plus it shows 3 motorised valves.

    I have a makeshift rig on my kitchen table.
    A. 13amp plug, L and N connection to relay 7 and 2 (coil)
    (This is the L connection I have planned for the existing motorised valves orange outputs.)
    B. 13amp plug, L and N connection to relay 1 and 8 (Power)
    c. L and N to table lamp, connected to 3 and 6.

    Switch on B, all ok, switch on A, lamp on, all ok. Switch A off, all ok lamp out. Switch off B, no power to lamp. Tried connecting 2 and 8, N to N, trips out. (N to N ??)

    Switch everything off. Apply 240 volt to 3 and 6. All ok, no voltage to 1,2,7 or 8. Fine, just what I want.

    Switch A and B on, lamp on. Apply 240v to 3 and 6, all trips out. Changed L and N over, still trips out. (This situation will occur when the new motorised valve calls for heat when the existing valves are on, quite often.)

    Help!!!

    Beeches.
     
  8. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    Do you have a spec sheet for the additional valve?
     
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