Economy 7 switching

[tubalcain]

I have used the switch connections in my economy 7 meter to send a power signal to my night storage heater (actually it's an electric aga). The Aga is switched off so no load switching is taking place yet when the economy seven kicks in at 12.30 every night the RCD trips out.

Am I doing something wrong?

 

[bernardgreen]

I have used the switch connections in my economy 7 meter to send a power signal to my night storage heater (actually it's an electric aga). The Aga is switched off so no load switching is taking place yet when the economy seven kicks in at 12.30 every night the RCD trips out.

Am I doing something wrong?

Probably

The current from the meter switch on the live wire is NOT going through the RCD on the way to the Aga but may ( depending on the wiring ) be returning to the meter via the neutral that does go through the RCD. That is un-balancing and therefore tripping the RCD

 

[tubalcain]

So... any ideas how I can wire it to avoid the tripping?

 

[Spark123]

Please explain exactly what you have done, you say you have wired it to your meter? Which RCD is tripping, is it on the E7 or the normal? Is there more than one supply to the AGA?

 

[tubalcain]

There are two supplies to the Aga: the 30A supply and a 2A timed supply telling the Aga that it's economy seven time. I only have the one RCD for the entire distribution board. My E7 meter has two connections that are normally open-circuit but go closed-circuit at off-peak times. I have used these to form a switch using a four-way terminal connector in the same way as you would with a light switch.

The 30A supply to the Aga is not even connected yet but the 2A E7 supply is wired into a FCU with a neon. When this comes on at night the RCD trips out.

 

[Spark123]

Sounds like you have not separated out your circuits, don't know if you should be tinkering about with an E7 meter (is it DNO property)? Can you draw us a diagram & scan it in? E7 and normal are usually separate fuse boards aren't they?
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[ELZ4742]

surely u have 1 board for e7 and another for the rest of the house?

 

[tubalcain]

Have posted a pic, link below. I have only one board. Meter is electronic as you will see.

http://img174.imageshack.us/my.php?image=meterss0.jpg

 

[Spark123]

Are you allowed to connect your own cables to the meter like that? There is a possibility these are not dry contacts, if they are not you may have a small cable protected by your service fuse. Are you on TT (earth electrode)?

 

[bernardgreen]

Are you allowed to connect your own cables to the meter like that? There is a possibility these are not dry contacts, if they are not you may have a small cable protected by your service fuse. Are you on TT (earth electrode)?

There appear to be only 5 terminals into the meter with [1] to [4] wired as

[1] Live IN
[2] Neutral In
[3] Neutral Out
[4] Live out

Therefore terminal [5] has to be connected to Live during econony 7 time.

But it is also connected directly to Live In

If the thin red wire on the left is going into same terminal [4] as the thick grey wire and is conected to any other circuit then you have made a big mistake.

That thin red wire into [5] has a 100 amp fuse behind it when the economy 7 is switched

That thin red wire going into [4] has the same 100 amp fuse behind in.

If that thin red wire going to [4] is connected to any circuit in the house that circuit has a 100 amp fuse feeding it. That circuit will NOT be isolated when the main switch is turned off.

From that circuit back feed via that ciorcuits MCB the Live bus in the consumer unit will be live even when the main switch is OFF. Therefore all circuits in the hosue will be live.



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[tubalcain]

Yes I'm on TT - earth electrode in the ground. If I'm doing something I shouldn't then I want to correct it - that's why I'm posting this - it's just that nobody seems to know how economy seven works these days.

When I was a kid we had a completely separate white meter that only supplied power when the clock said it was economy seven time. With this electronic meter supplying on the one board I need some sort of signal but nobody seems to know how it's done!

 

[bernardgreen]

Yes I'm on TT - earth electrode in the ground. If I'm doing something I shouldn't then I want to correct it - that's why I'm posting this - it's just that nobody seems to know how economy seven works these days.

When I was a kid we had a completely separate white meter that only supplied power when the clock said it was economy seven time. With this electronic meter supplying on the one board I need some sort of signal but nobody seems to know how it's done!

SEE PREVIOUS POST

You need to have a fused outlet installed by an electrician in liason with the electricity supply company that is power from the Economy 7 terminal on the meter. That supply is used to operate a contactor which provides you with a contact that closes durin economy 7. The two thin red wires then go to this contact t obe connected when the economy 7 is on.

 

[Spark123]

You must not connect the wires to the meter. As you have it the wires you have connected are bypassing the RCD and are fed by the DNO fuse. This is dangerous.
The terminal on the meter is for connection to a consumer unit which as you are on TT will need to be an RCD protected one or a separate RCD. I really think in the interest of safety you should have a qualified electrician do this work for you.

 

[bernardgreen]

You must not connect the wires to the meter. As you have it the wires you have connected are bypassing the RCD and are fed by the DNO fuse. This is dangerous.
The terminal on the meter is for connection to a consumer unit which as you are on TT will need to be an RCD protected one or a separate RCD. I really think in the interest of safety you should have a qualified electrician do this work for you.

Spark123
What is about a little knowledge is EXTREMELY DANGEROUS

I just realised that when the economy 7 came on the RCD tripped and gave the appearance of no electricity in the house. But that wire into 4 on the meter was feeding backward through an MCB keeping the bus bar live so the whole house had a live but no neutral making everything look as if it were dead but in fact all wires were live........LETHAL

 

[Spark123]

The addition is on a TT system without RCD protection too, doesn't look much larger than 2.5mm² single insulated cable fed from possibly a DNO fuse.