Immerson Wiring

Griffinx

Hi,

I bought a new immersion switch to replace a faulty one. The connectors are slightly different...theres no COM on the new switch. Before L Out was connected to COM...what should I wire L Out to on this switch. Also what the 20/250 terminal bottom left for?

Heres a pic of the new switch

Thanks

DublinDilbert

Effectively it’s two switches. The L out needs to be looped to the bottom left terminal of the other switch which selects bath or sink. The loop should be done with some 2.5mm sq.

Tell me how

Griffinx wrote: »

Hi,

I bought a new immersion switch to replace a faulty one. The connectors are slightly different...theres no COM on the new switch. Before L Out was connected to COM...what should I wire L Out to on this switch. Also what the 20/250 terminal bottom left for?

Heres a pic of the new switch

Thanks

Get an electrician dude.
It's fairly straightforward, if you know what you're doing.

No offence to you personally but it has potential to shock/kill/start fire if not done correctly. Ask in elec wholesaler for name of someone to stick it in for you.

K.Flyer

Tell me how wrote: »

Get an electrician dude.
It's fairly straightforward, if you know what you're doing.

No offence to you personally but it has potential to shock/kill/start fire if not done correctly. Ask in elec wholesaler for name of someone to stick it in for you.

100 % Totally agree with you.
With respect to the o.p., but If someone has to ask these type of questions it shows their lack of electrical knowledge and know-how and they should instead be leaving it to a qualified electrician to install it.

Griffinx

Tell me how wrote: »

Get an electrician dude.
It's fairly straightforward, if you know what you're doing.

No offence to you personally but it has potential to shock/kill/start fire if not done correctly. Ask in elec wholesaler for name of someone to stick it in for you.

I didn't ask for a lecture, just information

Pelvis Parsley

Griffinx wrote: »

I didn't ask for a lecture, just information

Knock yourself out so.

Tell me how

Griffinx wrote: »

I didn't ask for a lecture, just information

I felt I was not condescending.
Information is get someone who knows what they're doing or go ahead and risk claiming a Darwin award.

Have a good day.

Risteard81

Griffinx wrote: »

I didn't ask for a lecture, just information

Some good information is to get a Registered Electrical Contractor out to do this. They will understand how to fit it.

my3cents

Griffinx wrote: »

I didn't ask for a lecture, just information

Live and neutral from supply go to the two marked bottom right terminals.

Neutral top right takes the neutral connection from the immersion.

Next to the neutral out is the live out this is connected to the com terminal at the bottom left.

The the live out for the sink and bath are taken off at the top left as indicate on the switch.

So when switched on the main switch energizes the COM connection so the now live COM connection can be switched between sink or bath. The reason for the supply and out markings is because of the neon indicator use them the other way around and the neon would never go off.

OK surprised no one picked me up on that but I was WRONG

What was wrong was I automatically without thinking about it switched the Live connection. That doesn't work for a dual immersion because they have a common live and the neutral is switched.

Live and neutral from supply go to the two marked bottom right terminals.

Neutral top right takes the neutral connection from the immersion is looped to the COM at the bottom left.

Next to the neutral out is the live out this is connected to the com terminal at the bottom left this is the live supply to the immersion.

The the live out for switched neutral for the sink and bath are taken off at the top left as indicate on the switch.

Bruthal

Tell me how wrote: »

or go ahead and risk claiming a Darwin award.

We all risk claiming one of those every day

Risteard81

my3cents wrote: »

Live and neutral from supply go to the two marked bottom right terminals.

Neutral top right takes the neutral connection from the immersion.

Next to the neutral out is the live out this is connected to the com terminal at the bottom left.

The the live out for the sink and bath are taken off at the top left as indicate on the switch.

So when switched on the main switch energizes the COM connection so the now live COM connection can be switched between sink or bath. The reason for the supply and out markings is because of the neon indicator use them the other way around and the neon would never go off.

OK surprised no one picked me up on that but I was WRONG

What was wrong was I automatically without thinking about it switched the Live connection. That doesn't work for a dual immersion because they have a common live and the neutral is switched.

Live and neutral from supply go to the two marked bottom right terminals.

Neutral top right takes the neutral connection from the immersion is looped to the COM at the bottom left.

Next to the neutral out is the live out this is connected to the com terminal at the bottom left this is the live supply to the immersion.

The the live out for switched neutral for the sink and bath are taken off at the top left as indicate on the switch.

Not correct. Whilst the neutral will be switched inside the immersion (as an appliance essentially), to have single pole switching on the neutral pole of the switch would be a very, very serious breach of the Wiring Rules. Single pole switching must only ever be in the phase conductor.

Anyhow, it is clear that the OP doesn't know what he is doing and must not attempt this.

bmc58

Tell me how wrote: »

Get an electrician dude.
It's fairly straightforward, if you know what you're doing.

No offence to you personally but it has potential to shock/kill/start fire if not done correctly. Ask in elec wholesaler for name of someone to stick it in for you.

Don't mess with electricity in your home.Get a registered electrician,probably cost you€50 but it's well spent for peace of mind.

Bruthal

my3cents wrote: »

Live and neutral from supply go to the two marked bottom right terminals.

Neutral top right takes the neutral connection from the immersion.

Next to the neutral out is the live out this is connected to the com terminal at the bottom left.

The the live out for the sink and bath are taken off at the top left as indicate on the switch.

So when switched on the main switch energizes the COM connection so the now live COM connection can be switched between sink or bath. The reason for the supply and out markings is because of the neon indicator use them the other way around and the neon would never go off.

OK surprised no one picked me up on that but I was WRONG

What was wrong was I automatically without thinking about it switched the Live connection. That doesn't work for a dual immersion because they have a common live and the neutral is switched.

Live and neutral from supply go to the two marked bottom right terminals.

Neutral top right takes the neutral connection from the immersion is looped to the COM at the bottom left.

Next to the neutral out is the live out this is connected to the com terminal at the bottom left this is the live supply to the immersion.

The the live out for switched neutral for the sink and bath are taken off at the top left as indicate on the switch.

You were more right the first time.

my3cents

Bruthal wrote: »

You were more right the first time.

Its an interesting logic problem but you have to actually draw it out or try it with a typical Irish dual immersion to see whats possible and what isn't.

The logic issue is that you only have 3 wires plus earth to work with.

Bruthal

my3cents wrote: »

Its an interesting logic problem but you have to actually draw it out or try it with a typical Irish dual immersion to see whats possible and what isn't.

The logic issue is that you only have 3 wires plus earth to work with.

When drawn out it can be seen that it's possible to get it wrong and bypass the stat.which Is not good. So it is important the person knows what they are at.

my3cents

Bruthal wrote: »

When drawn out it can be seen that it's possible to get it wrong and bypass the stat.which Is not good. So it is important the person knows what they are at.

Checked my own and its switched live

The thermostat and thermal cutout switch the neutral when you'd expect them to switch the live but can't because they are shared.

K.Flyer

my3cents wrote: »

Checked my own and its switched live

The thermostat and thermal cutout switch the neutral when you'd expect them to switch the live but can't because they are shared.

Yup, always been like that. Only exception you would see is on a single element, then live goes through the stat.

bmc58

Griffinx wrote: »

I didn't ask for a lecture, just information

Cop on Gr.Don't mess with electrics for the sake of a few Euro if you don't know what youre at.You asked for advice and you got sensible advice.Pay a few Euro for a qualified person and sleep safe.

Bruthal

my3cents wrote: »

Checked my own and its switched live

The thermostat and thermal cutout switch the neutral when you'd expect them to switch the live but can't because they are shared.

The earlier mentioned example about being possible to bypass the stat with incorrectly connected immersion flex, if L is connected to brown and N to black in the flex, the 3kw bath and 2kw sink are now in series, with the stat out of the circuit.

Its less likely now as blue is N in flex and most will connect it as such, but anything is possible with diy jobs. Years ago blue was one of the Lives to the elements.

LenWoods

Speaking of immersion switches;
Thought I'd share some money and time saving details;
I've fitted a TimeGuard immersion switch to govern the flow of power to my already fitted dual element immersion switch;
Saves me time not having to go back upstairs to turn it off aswell as not having to remember to turn it off atall;
I've also fitted a plug in version to the clothes iron but that's a separate thread altogether lol
Link to supplier https://www.electricalwholesaler.ie/products/heatingventilation/heatersradiators/timeclocksheatcontrols/13atimeguardtgbt4boostmaster2hourelectronicboostti
Picture attached below

Bruthal

A good way to do it now in terms of controlling the immersion, is a sonoff relay. And 20 amp contactor.

LenWoods

Bruthal wrote: »

A good way to do it now in terms of controlling the immersion, is a sonoff relay. And 20 amp contactor.

Sorry I misread your post lol sorry

coylemj

LenWoods wrote: »

Speaking of immersion switches;
Thought I'd share some money and time saving details;
I've fitted a TimeGuard immersion switch to govern the flow of power to my already fitted dual element immersion switch;
Saves me time not having to go back upstairs to turn it off aswell as not having to remember to turn it off atall;

The problem with that type of switch is that it only gives you the boost function, at the expense of having a fully programmable timer. You can have both.

For example, this Sangamo model gives you three timer (on/off) programs plus a boost function. You simply press the Boost buttom 1-3 times for 30m/1 hr/2hrs boost.

https://www.sangamo.co.uk/collections/immersion-controllers/products/powersaver-select?variant=41545698502

But for the true couch potato, nothing beats this guy which I have installed, the Timeguard Wi-Fi timer. You control it from the mobile app and it includes a one-hour boost button. It connects to your house wi-fi and you can control it from anywhwere via the app.

https://www.timeguard.com/products/time/immersion-and-general-purpose-timeswitches/wi-fi-controlled-fused-spur

LenWoods

coylemj wrote: »

The problem with that type of switch is that it only gives you the boost function, at the expense of having a fully programmable timer. You can have both.

For example, this Sangamo model gives you three timer (on/off) programs plus a boost function. You simply press the Boost buttom 1-3 times for 30m/1 hr/2hrs boost.

https://www.sangamo.co.uk/collections/immersion-controllers/products/powersaver-select?variant=41545698502

But for the true couch potato, nothing beats this guy which I have installed, the Timeguard Wi-Fi timer. You control it from the mobile app and it includes a one-hour boost button......

https://www.timeguard.com/products/time/immersion-and-general-purpose-timeswitches/wi-fi-controlled-fused-spur

The wifi model was still in development when I bought mine,
I'm not a fan of the time clock model because; if I got hit by a bus on my way home from work to wash the disches; the immersion will still heat the water which I wouldn't be running for atleast a week,
So I'm lying in the ambulance thinking how I cant go to work tomorrow or pay the mortgage then I remember the immersion is on a time clock ah no... :eek: as if it couldn't have gotten any worse there goes the electricity bill aswell

John.G

The boost option is a great addition to any immersion control. Even if the immersion was left switched on constantly the thermostat will still cut off the power when the cylinder is up to temperature so worst case if one is away from the house is a daily loss of ~ 3/4 kwh, say 70 cent/day, which, while undesirable, will not break the bank.

2011

worst case if one is away from the house is a daily loss of ~ 3/4 kwh, say 70 cent/day, which, while undesirable, will not break the bank.

That is going to depend on a few factors such as the quality of the installation of the tank and what the stat set point is.

Example: Keeping a very large poorly insulated tank to 70 degrees could cost a lot more.

2011

Just to add: The Sonoff TH16 devices have a configurable boost timer function available.

John.G

2011 wrote: »

That is going to depend on a few factors such as the quality of the installation of the tank and what the stat set point is.

Example: Keeping a very large poorly insulated tank to 70 degrees could cost a lot more.

Yes, of course, but I would say that the days of the loosely fitted lagging jacket are mostly in the past and a loss of 0.4C to 0.8C/hr, depending on insulation thickness and cylinder size, is reasonable to assume. I have attached a calculation which I think came/comes from the SEAI and which I've edited to give the temperature loss/hour.

John.G

Bruthal wrote: »

When drawn out it can be seen that it's possible to get it wrong and bypass the stat.which Is not good. So it is important the person knows what they are at.

For info only, here's one, (mine) installed in 1972 and still working perfectly, only a on/off switch, with the sink/bath c/o switch not very conveniently located on top of the immersion, it has two (contact type) thermostats, one set at 60c & the other, I think, at 80C for the bath. How times have changed, for the better, in most cases.

Qelres.

Immersion heaters must be the worst electrical appliance ever.

More problems than you can shake a stick at

I also don't get the current obsession with smart control of same

disposableFish

Qelres. wrote: »

I also don't get the current obsession with smart control of same

It helps make them a little less terrible.

gidxl03

After reading this post end-to-end and multi-meter testing of the same switch bought in Woodies, here's my understanding;

Mains-in Neutral to bottom right Supply-N. Internally connected to N-OUT on top right (impedance 0 Ohms).
Mains-in Live to bottom middle Supply-L. Internally connected via Single Pole(On/Off) switched to L-OUT on top right.
L-OUT on top right has to be externally connected via your own jumper cable (2.5mm sq) to 20Amp/250V on bottom left.
20Amp/250V L-COM on bottom left connected to either Sink-L or Bath-L via Dual Pole switch (Sink or Bath, 3Ohm-closed or 50Ohm-open)
Sink-L on top left connects to SINK of immersion element
Bath-L on top left connects to BATH of immersion element
N-OUT on top right to N of immersion element

Note:
L-OUT to N-OUT is 23Ohm (Resistance of the cold neon light)

Question:
Why did the manufacturer not internally wire L-OUT to 20/250-L-COM?
Why is impedance of open switch to sink/bath only 50 Ohm?
Does anyone have a link to the spec?
Have tested this wiring and although it is heating the immersion as expected, the neon light does not come on in any switch configuration.

2011

gidxl03 wrote: »

After reading this post end-to-end and multi-meter testing of the same switch bought in Woodies, here's my understanding;

In my opinion this is not a great place to purchase electrical accessories as they tend to be overpriced and often of questionable quality. Having said that I have used them when stuck and was delighted to have to option (as they are open on Sundays). You will have more choice and pay less in a proper electrical wholesaler.

Mains-in Neutral to bottom right Supply-N. Internally connected to N-OUT on top right (impedance 0 Ohms).

Where the terminals are placed will depend on the manufacturer.
The multimeter will measure resistance, not impedance which is fine for a heating element.
Remember multimeters have an internal battery as such are DC which will only “see” the resistance component of impedance.

As you say it should be a very low resistance between neutral in and neutral out terminals as they are connected together internally.

Mains-in Live to bottom middle Supply-L. Internally connected via Single Pole(On/Off) switched to L-OUT on top right.
L-OUT on top right has to be externally connected via your own jumper cable (2.5mm sq) to 20Amp/250V on bottom left.

Again the terminal positions / layout and whether there is a jumper cable or not will depend on the manufacturer.

Note:
L-OUT to N-OUT is 23Ohm (Resistance of the cold neon light)

Nope.
If the neon was 23 Ohms then at 230V according to Ohm's Law it would draw 10 amps and would consume 2.3 kW (as much as some kettles)

Question:
Why did the manufacturer not internally wire L-OUT to 20/250-L-COM?

Sorry I don't really understand the question. However maybe this will answer it for you: Some manufacturer's will do the internal wiring, some won't. Obviously they can save a few bob by getting the end user to do it.

Why is impedance of open switch to sink/bath only 50 Ohm?

Its not. The resistance (or impedance) across a properly working switch is far higher than that.
I assume you are measuring the resistance with the cable or immersion elements connected? To measure the resistance across a switch have everything disconnected otherwise you will be measuring the resistance of whatever is connected.

Does anyone have a link to the spec?

The wiring arrangement is generally marked on the back of the switch. This will vary depending on who made it.

Have tested this wiring and although it is heating the immersion as expected, the neon light does not come on in any switch configuration.

Either the neon is faulty or it is not connected properly.

By the way a 3 kW element will have a resistance of around 17.6 Ohms and a 2 W element will have a resistance of around 26.5 Ohms.

Ensure that all connections are tight!

Bruthal

The 23 ohms read across L-N (out) is reading one of the elements, and will be approx 17 or 26 ohms for bath/sink respectively. Which one is read depends on the bath/sink switch position.

An ohms reading sink to bath will give the bath and sink elements in series, so for the above would be 43 ohms.

Depending on the immersion elements, and how accurate the measuring meter, that is what I would think has been measured to give the results seen.

kramer1

Qelres. wrote: »

Immersion heaters must be the worst electrical appliance ever.

More problems than you can shake a stick at

I also don't get the current obsession with smart control of same

No, they're great. Last for years, easy to change and very little problems with them if installed correctly initially.

2011

Qelres. wrote: »

Immersion heaters must be the worst electrical appliance ever.

They are expensive to use, but as a standalone back up to a boiler they are great.

More problems than you can shake a stick at

They are very simple and cheap to fix if there is an issue. I think a new immersion element is around €30. Personally I have found them to be very reliable.

I also don't get the current obsession with smart control of same

It is so cheap to install smart control and it can save so much money. A Sonoff TH16 controller is around €15 and it uses a free app. Where could you go wrong?

looksee

Qelres. wrote: »

Immersion heaters must be the worst electrical appliance ever.

More problems than you can shake a stick at

I also don't get the current obsession with smart control of same

I had one fire and one narrowly-avoided fire directly related to immersion heaters, mostly because of the time clocks. I don't have a timer on my current one and only use it in case of absolute necessity.

2011

looksee wrote: »

I had one fire and one narrowly-avoided fire directly related to immersion heaters, mostly because of the time clocks. I don't have a timer on my current one and only use it in case of absolute necessity.

If installed correctly they are very safe.
Why do you think the timer increased the risk?

kramer1

2011 wrote: »

If installed correctly they are very safe.
Why do you think the timer increased the risk?

Probably people using the wrong clocks. The ones that were rated 5/6 amp looked a lot like the 16 amp version s

gidxl03

Bruthal wrote: »

The 23 ohms read across L-N (out) is reading one of the elements, and will be approx 17 or 26 ohms for bath/sink respectively. Which one is read depends on the bath/sink switch position.

An ohms reading sink to bath will give the bath and sink elements in series, so for the above would be 43 ohms.

Depending on the immersion elements, and how accurate the measuring meter, that is what I would think has been measured to give the results seen.

@2011 + Bruthal : Many thanks for the reply.

Re: Where the terminals are placed will depend on the manufacturer.
Note that my post was w.r.t. the image that the OP provided (mine looks identical). Also, turns out that my wife did not get it in Woodies.

Re: The multimeter will measure resistance, not impedance which is fine for a heating element.
Got it !

Re If the neon was 23 Ohms then at 230V according to Ohm's Law it would draw 10 amps and would consume 2.3 kW (as much as some kettles)
I thought that the resistance of the cold neon would be much much less that the resistance a millisec after it has lit up. It has been a very long time since I studied electronics .. but I think it is called 'in-rush' current. Anyhow, interesting but completely academic.

Re the expected resistance
Many thanks for the info on resistance of sink and bath, its a good reference.

Re the neon light not working. Confession: I should have mentioned that on my first attempt to put the switch in series with a timer, I pinched the L wire input to the timer when screwing the timer face back on. So the screw next to the trapped L may have been live - yikes! The screw is not connected to ground (multimeter test) so I don't know how the MCB tripped but thankfully it did. I replaced all the wiring, found that the old timer was broken (power light always on, even when switch was off) so I replaced it (correct rating for immersion) and now all is working except for the neon light on the switch (I've monitored it closely while immersion turns on and off so am confident that it is safe but, as advised by an earlier poster, would have got an electrician if I had to start over). I still don't know how a short in the timer could have broken the neon in the on/off switch since the large current of the short would not have gone through it.