Energy savings, do you care?

And how is that low voltage made? Think!

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg
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Through a low voltage transformer that provides protection.

What are YOU thinking of??? Why do I have to do your thinking for you?

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  Rick C. 

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Reply to
Ricketty C

No. That is not enough for bathroom use.

Then start thinking for once :-)

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

What is wrong with a SELV

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circuit ?

Reply to
upsidedown

In the end it's expensive, you can't just use a doorbell transformer and call it a day. The stuff must be certified. Then you have all kinds of electrical codes, different between countries. For example, in many jurisdictions you must maintain a significant separation between LV control wires and mains cables going into the same bathroom. Can become a real headache for installers. And on and on.

I have designed a lot of stuff for markets with similar rules and the regulatory work alone is no small feat.

In Europe, another factor is that homes are generally brick or concrete walled. You can't just fish another cables through the studs behind drywall or Hardiebacker, you'll be slotting and busting through walls using hydraulic hammer tools. BTDT. That adds a major cost.

Wireless may be the better option here, especially considering retrofits and full bathroom remodels.

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

Assuming SELV, it's absolutely enough.

.Zone 1 (high splash risk like in a shower enclosure above the tray, above a bath tub) . .Requires electrical products to be IPX4 or better, or SELV with the .transformer located beyond zone 2.

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  Jasen.
Reply to
Jasen Betts

Wireless is better

But, there are installations where the pump is below the sink, so no long routing of cable

Cheers

Klaus

Reply to
Klaus Kragelund

Below the sink is very easy, provided there is a power outlet. In the neighborhood where our German house was that was only the case for the full baths and those outlets (for razors and hair dryers) were very high, about 1 meter above the sinks. Often they were integrated into the above-sink mirror cabinet. Alibert and similar brands, that hold tooth paste, medicines and stuff. Not sure how you'd safely place a power supply there.

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The guest bath only had a light above the sink so that has no power during the day. The other aspect to consider is noise. The pump has to be very quiet because often the lady of the house would complain if there is a buzz while "doing business" :-)

Another question is, what to do about the shower or the bathtub?

In our house in Germany the recirculating pump was central, near the boiler in the basement. However, eventually we just turned it off and when a water line broke and had to be replaced the plumber didn't want to hook up the return line. He said it's not done much anymore. That was in the 90's.

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

In most jurisdictions you are not allowed to run the cables close to mains wiring and that's not a trivial matter in a cramped bathroom. Klaus is likely thinking more about Europe first and those rooms aren't big over there.

Then, Klaus was thinking about a pump under the sink. That requires a permanently plugged in larger power supply. Not really easy in bathrooms and outlets in the popular mirror cabinets are not meant for permanent connections. That's all we had in our house in Germany and that was quite normal in the neighborhood.

This is definitely not a slam-dunk situation.

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

r

g with instant on? In the households in the EU the house current provides for more power availability in a standard circuit, over 2 kW vs about 1.4 k W here. That's plenty for instant on.

240v 32A is 7.7kW.

NT

Reply to
Tabby

The Dr. Hobbs understands all the losses involved as well as anyone I expect, no actual point to make.

Reply to
bitrex

You aren't making sense. The low voltage CONTROLS the high voltage. It presents no safety problems. What image do you have in your mind about this?

Do you think your thermostat has high voltage in it? Does it need to be treated like a high voltage wiring fixture because it controls a high voltage and high power circuit?

Why can't you communicate what you are talking about?

You are so difficult to communicate with because you don't explain your thinking. You just toss insults. But then I guess that's just you. So do I have to do your thinking and your communicating also?

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  Rick C. 

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Reply to
Ricketty C

Scoffing at doctors is fashionable in America these days I thought you would be happy.

Reply to
bitrex

So they can't use a doorbell transformer to work a doorbell? What are doorbell transformers used for?

Yeah, so? They have Ethernet and other low voltage wiring all through the house now. Where's the problem?

So? Your head hurts from the thinking about it?

I used to install burglar alarms similarly. So?

Yawn! What is going on with you? Do you just like to argue for arguments sake?

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  Rick C. 

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Reply to
Ricketty C

to

l

or

ong with instant on? In the households in the EU the house current provide s for more power availability in a standard circuit, over 2 kW vs about 1.4 kW here. That's plenty for instant on.

I was thinking more of the 9 amp circuits that I believe are common in the UK. We tend to have 15 amp 120 volts in the US, sometimes 20 amps in certa in uses. 20 amps at 120 volts is practically the same as 9 amps, 240 volts and is a fair amount of water heating. It may not be enough for a shower though. I did some not so quick calculations that show 9 amp, 240 volts wi

shower uses around 2 gal a minute, so more power is needed, around 6 times as much or more like 60 amps at 240 volts!

But then who cares if they need to wait 30 seconds to get hot water for the shower? When having forgotten to turn the hot water heater back on the ot her day, I found the water in the tank is sufficiently hot to take a shower in just a few minutes, less than 10. I'm curious as to just how much the water heater is actually on when no water is drawn.

My utility provides hour by hour usage data and I see intermittent spikes i n my usage that are likely the water heater. There is some granularity in the kWhr reading but it looks like 0.4 kWHr each 5 hours for around 80 watt s consumption not counting hot water drawn.

I'm glad I did this calculation. Installing a timer on the hot water heate r will save me around $40 a year on my TOU bill. Marginally worth it since it's not something I can just buy and install without either spending a bu nch of money (240 volt stuff tends to be commercial $$$) or having to rig u p a relay to control the 240 from a 120 volt device. Not going to worry wi th that just now.

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  Rick C. 

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Reply to
Ricketty C

UK uses 32A circuits with 13A outlets for GPOs

not enough though.

This one is 6.4kW:

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  Jasen.
Reply to
Jasen Betts

SELV just requires that the double insulated transformer is feeding a single circuit, which is separated from ground and other circuits. That shouldn't be too expensive to implement.

That is an other national issue.

I have never seen hydraulic hammers used for making holes into concrete walls at hones. An electric drill with some hammer action is sufficient.

If the pump is relatively close and fed from the same phase, why not use some form of power line communication ?

Reply to
upsidedown

t to

ill

rm

nd or

ly

wrong with instant on? In the households in the EU the house current provi des for more power availability in a standard circuit, over 2 kW vs about 1 .4 kW here. That's plenty for instant on.

e UK. We tend to have 15 amp 120 volts in the US, sometimes 20 amps in cer tain uses. 20 amps at 120 volts is practically the same as 9 amps, 240 vol ts and is a fair amount of water heating. It may not be enough for a showe r though. I did some not so quick calculations that show 9 amp, 240 volts

e shower uses around 2 gal a minute, so more power is needed, around 6 time s as much or more like 60 amps at 240 volts!

he shower? When having forgotten to turn the hot water heater back on the other day, I found the water in the tank is sufficiently hot to take a show er in just a few minutes, less than 10. I'm curious as to just how much th e water heater is actually on when no water is drawn.

in my usage that are likely the water heater. There is some granularity i n the kWhr reading but it looks like 0.4 kWHr each 5 hours for around 80 wa tts consumption not counting hot water drawn.

ter will save me around $40 a year on my TOU bill. Marginally worth it sin ce it's not something I can just buy and install without either spending a bunch of money (240 volt stuff tends to be commercial $$$) or having to rig up a relay to control the 240 from a 120 volt device. Not going to worry with that just now.

9A circuits don't exist here, and afaik never have. (I'm reasonably familia r with wiring practices going back to around 1910.) Sockets circuits are mo stly 32A, some 20A, some 30A, a few 15A or 16A.

NT

Reply to
Tabby

AFAIK running SELV close to mains wire is ok. The insulation on the wire just needs to have double insulation from bare wire to wire. So in principle basic insulation on each wire itself. Right?

Cheers

Klaus

Reply to
Klaus Kragelund

u?

ra-low_voltage_(SELV)

SELV transformer is not expensive at all. Notice for this application, just getting input from a button, it needs no power at all. So a coreless trans former on the PCB and your done. Cheap as sh*t, probably a couple of cents (you can even just look at the impedance of the transformer, to detect a sh ort of the button)

Cheers

Klaus

Reply to
Klaus Kragelund

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