Does this device exist?

[et...@whidbey.com]

My brother's wife wants a small water heater under the kitchen
sink. Not an instant hot water type but one that holds a couple
gallons.
There is a receptacle under the sink but it also powers the
diswasher. I am concerned that if both the dishwasher and the water
heater are on at the same time it will pop the breaker.
I am looking for a device that will allow the water heater to be on
until the diswasher starts drawing a certain amount of current, at
which point the power to the heater would be turned off.
The power to the dishwasher needs to be on all the time, only the
heater should be switched. A switch for the water heater cannot be
added. The solution needs to be plug and play and require no input
from anyone using the diswasher.
It seems to me that something like this must be available but I
can't think of what it would be called and my brain is apparently too
fuzzy this morning to get google to come up with something for me.
I am willing to build the device myself if need be but a purchased
product would be better.
Thanks,
Eric

[tabb...@gmail.com]

A relay is all you need. Remove the coil & rewind with a small number of turns of thick wire. Now when enough current goes to the dishwasher, the water heater is turned off. I'd use 2 relays the same, one to experiment, the 2nd for the final unit.


NT

[peterw...@gmail.com]

https://www.bosch-thermotechnology.us/ocsmedia/optimized/full/o416419v272_Bosch_Indirect_Tanks_(1).pdf

It is called a "Point-of-Use" water heater.

Now, some Basic Electricity 100:

The POU *STORAGE* water heater draws twelve (12) amps at rated nameplate.
The typical dishwasher with an exposed internal heating element is rated at eleven (12) amps.

We keep a Bosch that does not have an exposed element but does have an on-board flash heater, and so also uses 12 A.

There are two solutions that come immediately to mind. Use a at true instant-hot for your sink water - these devices, typically, run under seven (7) amps. Then, even if you feed the dishwasher from the same line, you would be in no danger of popping a 20 A breaker - the minimum that should be in a kitchen in any case.

Or, run a second line directly to the dishwasher. Which is the way it should be done in any case.

Note that instant-hot water heaters will give you all the hand-use water you want, and nicely support a dishwasher such as it will require minimal use of its on-board heater.

Peter Wieck
Melrose Park, PA

[Wond]

If you are in North America, and that is a "duplex" receptacle, its
likeley to be an "appliance" outlet, that is, each side wired to a
separate breaker. Check the labelling in the box to find out, or measure
the voltage between the two "hot" connectors. 230V means you're good to
go.

[peterw...@gmail.com]

On Monday, September 30, 2019 at 12:00:14 PM UTC-4, tabb...@gmail.com wrote:

> A relay is all you need. Remove the coil & rewind with a small number of turns of thick wire. Now when enough current goes to the dishwasher, the water heater is turned off. I'd use 2 relays the same, one to experiment, the 2nd for the final unit.

The good folk in Quincy, MA are recoiling in horror!

DO NOT EVEN CONSIDER this option, most especially if you have any other living things in your household.

[et...@whidbey.com]

On Mon, 30 Sep 2019 16:27:16 -0000 (UTC), Wond <lo...@the.ether.net>
wrote:

You may be correct about that being on two circuits. I have my doubts
because of the age of the house and because of other flaky things
found in his house, but since the wiring SHOULD have been inspected,
maybe you are correct. I'll have my brother check.
Eric

[et...@whidbey.com]

Point of use water heaters don't provide enough hot water to wash a
load of dishes. But a small water heater will. I use one in my shop.
My brother is not gonna add another line because of the expense.
I can buy a delay relay that is made for shop vacuum systems that
is plug and play, but these devices only delay the turning on by 7
seconds of a load. I need to keep ne load off while the other is on.
Eric

[tabb...@gmail.com]

An instant water heater that only takes 7A, whether at 110 or 240v, is not going to produce a lot of hot water. Water heating is energy intensive.

And no dishwasher here is designed to support hot water intake.


NT

[tabb...@gmail.com]

On Monday, 30 September 2019 17:30:12 UTC+1, pf...@aol.com wrote:

> On Monday, September 30, 2019 at 12:00:14 PM UTC-4, tabby wrote:
>
> > A relay is all you need. Remove the coil & rewind with a small number of turns of thick wire. Now when enough current goes to the dishwasher, the water heater is turned off. I'd use 2 relays the same, one to experiment, the 2nd for the final unit.
>
> The good folk in Quincy, MA are recoiling in horror!
>
> DO NOT EVEN CONSIDER this option, most especially if you have any other living things in your household.
>
> Peter Wieck
> Melrose Park, PA

I see you offer zero basis for this claim. It's just a basic demand management unit.

[Ralph Mowery]

In article <f2908cdb-b309-4f82...@googlegroups.com>,
tabb...@gmail.com says...

>
> And no dishwasher here is designed to support hot water intake.
>
>
>

My dishwasher said to hook it to the hot water line.

[tabb...@gmail.com]

On Monday, 30 September 2019 21:53:42 UTC+1, Ralph Mowery wrote:
> In article <f2908cdb-b309-4f82...@googlegroups.com>,
> tabbypurr says...

> >
> > And no dishwasher here is designed to support hot water intake.
> >
> >
> >
>
> My dishwasher said to hook it to the hot water line.

in what country?

[Ralph Mowery]

In article <a84408b3-08cf-46f6...@googlegroups.com>,
tabb...@gmail.com says...

>
> > My dishwasher said to hook it to the hot water line.
>
> in what country?
>
>

In the good old USA .


https://www.whirlpool.com/content/dam/global/documents/201608/installati
on-instructions-W10806908-RevC.pdf


Copy and paste from online manual.

WATER SUPPLY REQUIREMENTS
? This dishwasher has a water heating feature and also
requires a connection to a hot water supply line.
? A hot water line with 20 to 120 psi (138 to 862 kPa)
water pressure can be verified by a licensed plumber.
? 120°F (49°C) water at dishwasher
?

[tabb...@gmail.com]

On Monday, 30 September 2019 22:39:31 UTC+1, Ralph Mowery wrote:
> In article <a84408b3-08cf-46f6...@googlegroups.com>,
> tabbypurr says...

> >
> > > My dishwasher said to hook it to the hot water line.
> >
> > in what country?
> >
> >
>
> In the good old USA .

US washing appliances are quite different to ours. Why I don't know.


NT

[Ralph Mowery]

In article <35769e99-a32b-4e0b...@googlegroups.com>,
tabb...@gmail.com says...

>
> > > in what country?
> > >
> > >
> >
> > In the good old USA .
>
> US washing appliances are quite different to ours. Why I don't know.
>
>
> NT
>
>

Especially when many of the US appliances are not made in the US any
more.

[Fox's Mercantile]

On 9/30/19 3:48 PM, tabb...@gmail.com wrote:
> And no dishwasher here is designed to support hot water intake.
>
>
> NT

The breadth of your ignorance never fails to amaze me.
My dishwasher in the kitchen connect to the hot ware line.
And it will NOT run with cold water.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

[whit3rd]

On Monday, September 30, 2019 at 5:08:11 PM UTC-7, Fox's Mercantile wrote:
> On 9/30/19 3:48 PM, tabb...@gmail.com wrote:
> > And no dishwasher here is designed to support hot water intake.

> The breadth of your ignorance never fails to amaze me.
> My dishwasher in the kitchen connect to the hot ware line.
> And it will NOT run with cold water.

My dishwasher has internal heat for the final rinse (to meet a NSF hot-water
final rinse temperature requirement). It worked fine, both washing and
rinsing, on cold water (when my water heater was on vacation...) though it
is intended to be plumbed into the hotwater line.

During the water heater replacement, I removed about 20 feet of
rusty iron pipe, replumbed with copper, and the flow is a lot better now.

[ehsjr]

Assuming the wiring is correct:
In the USA a standard duplex receptacle is wired for 120 volts.
A receptacle wired for 230 (240) will not be a duplex.

Ed

[peterw...@gmail.com]

On Monday, September 30, 2019 at 4:40:22 PM UTC-4, et...@whidbey.com wrote:

> Point of use water heaters don't provide enough hot water to wash a
> load of dishes.

Eric:

a) Unless you are using a dishwasher from the POS Manufacturing Company, Hangsen, China, it *DOES NOT NEED* very hot water to operate. The on-board heater (NSF requirement) will manage the difference between incoming water temperature and that necessary to clean the dishes.
b) And, if you are using a dishwasher made in the last 3 - 5 years, and from a reputable manufacturer, it will use very little water relative to hand-washing. So, if a POU device will be adequate for doing dishes in the sink, it will be equally adequate to supply a dishwasher.

As a point of comparison, our 10-year old Bosch (made in Tennessee) uses less than 4 gallons of water in the "Scrub-Paint-From-a-Board" mode, and about 0.870 KW of energy. Nor do we have to pre-wash the dishes. Anything smaller than cherry and softer than a hard nut will be handled. Advanced for its day, commonplace now.

[peterw...@gmail.com]

On Monday, September 30, 2019 at 4:48:09 PM UTC-4, tabb...@gmail.com wrote:
> An instant water heater that only takes 7A, whether at 110 or 240v, is not going to produce a lot of hot water. Water heating is energy intensive.
>
> And no dishwasher here is designed to support hot water intake.

Another hip-shot going wild.

a) The ECOSmart line here in the USA produces a 7A under-sink unit that produces 1.3 GPM (4.92 LPM) at a 50-degree F (10 C) rise. The idea is not to scald a user (110 F and up).

b) Dishwashers rated by the NSF (National Sanitation Foundation) will do the final rinse for a residential dishwasher at 165 F (74 C) minimum. Some go to 180 F as an option. Yes, they are to be required to be connected to the hot water line, if only to reduce stress on the internal heater.

http://www.nsf.org/consumer-resources/appliances/dishwashers

[peterw...@gmail.com]

On Monday, September 30, 2019 at 4:49:08 PM UTC-4, tabb...@gmail.com wrote:

> I see you offer zero basis for this claim. It's just a basic demand management unit.

Nope, no basis whatsoever, other than the National Electrical Code as published by the NFPA out of Quincy, MA.

[Bob Engelhardt]

Well, it may be a very bad idea, but the NEC doesn't cover stuff plugged
into receptacles, as this dishwasher is.

[peterw...@gmail.com]

On Tuesday, October 1, 2019 at 7:59:16 AM UTC-4, Bob Engelhardt wrote:

> Well, it may be a very bad idea, but the NEC doesn't cover stuff plugged
> into receptacles, as this dishwasher is.

It does cover kludged relays that control line-voltage appliances.

[et...@whidbey.com]

Once again I fail to make myself clear. The water heater is for hand
washing dishes, not the diswasher. That's why the heater can be off
when the dishwasher is running. In my brother's house dishes are
washed more by hand than by dishwasher but bioth get used.
Eric

[peterw...@gmail.com]

On Tuesday, October 1, 2019 at 10:21:31 AM UTC-4, et...@whidbey.com wrote:

> Once again I fail to make myself clear. The water heater is for hand
> washing dishes, not the diswasher. That's why the heater can be off
> when the dishwasher is running. In my brother's house dishes are
> washed more by hand than by dishwasher but bioth get used.
> Eric

Then, even the smallest POU heater will be fine for dishes, as long as the user does not leave it on "BLAST". Keep in mind that the average handwash for two users, one meal, is about 2.75 gallons (10.5 liters) of water. Modern dishwashers use, typically, less than a gallon (2.75 liters).

You are over-complicating a rather simple problem.

[John-Del]

On Tuesday, October 1, 2019 at 10:21:31 AM UTC-4, et...@whidbey.com wrote:

> Once again I fail to make myself clear. The water heater is for hand
> washing dishes, not the diswasher. That's why the heater can be off
> when the dishwasher is running. In my brother's house dishes are
> washed more by hand than by dishwasher but bioth get used.
> Eric

An on-demand system would be perfect for him and take up much less space. Why doesn't your brother want an instant demand heater?

If it's electrical draw that exceeds the wiring, I'd just snake in new wiring and a new breaker and use the on demand heater.

[Wond]

Where I am, the hardware is the same. The installer simply breaks out
the connector tab between the 'hots'.

[Ralph Phillips]

On 10/1/2019 9:23 AM, et...@whidbey.com wrote:

> Once again I fail to make myself clear. The water heater is for hand
> washing dishes, not the diswasher. That's why the heater can be off
> when the dishwasher is running. In my brother's house dishes are
> washed more by hand than by dishwasher but bioth get used.
> Eric
>

*blink*

Simple.

Don't hand wash dishes if the dishwasher is going.

I don't see the problem or the need to automate something that can be
handled by the grey matter between the ears.

RwP

[et...@whidbey.com]

Actually, I'm not. They tried a small instant hot heater. It did not
provide enough hot water. They saw the small water heater I use in my
shop and they think it is perfect. It just draws too much current to
be used at the same time a dishwasher is heating.
Eric

[et...@whidbey.com]

On Tue, 1 Oct 2019 07:49:46 -0700 (PDT), John-Del <ohg...@gmail.com>
wrote:

Sheesh! He is not gonna run a new wire. I already said that. It is not
an easy task. Power would need to come down from the attic.
Eric

[peterw...@gmail.com]

On Tuesday, October 1, 2019 at 3:19:33 PM UTC-4, et...@whidbey.com wrote:

> Actually, I'm not. They tried a small instant hot heater. It did not
> provide enough hot water. They saw the small water heater I use in my
> shop and they think it is perfect. It just draws too much current to
> be used at the same time a dishwasher is heating.

The solution is, then, contained in how you stated the problem.

a) A tankless POU water heater uses current only when flowing.
b) A dishwasher wants hot water to feed it, but it does not require it to function properly. NSF regulations see to that.
c) If your brother is able to restrain himself to not running hot water to the sink except when the dishwasher is OFF, just go with a larger tankless device. They come (in the US) up to 18 A at 120 V.

Under your sink, run the tankless heater to a separate dispenser - some even come that way. Use the regular hot water line to feed the dishwasher, and the cold line to feed the sink. Note that separate dispenser devices will make water hot enough for tea or instant coffee at one setting, then dial back to sub-scalding temperatures for washing use. Handy little things.

Ultron comes to mind as a brand name.

[Bob Engelhardt]

On 10/1/2019 8:03 AM, pf...@aol.com wrote:
> On Tuesday, October 1, 2019 at 7:59:16 AM UTC-4, Bob Engelhardt wrote:
>
>> Well, it may be a very bad idea, but the NEC doesn't cover stuff plugged
>> into receptacles, as this dishwasher is.
>
> It does cover kludged relays that control line-voltage appliances.

Only if it's hard wired, If it plugs in, it's an appliance itself.

[gghe...@gmail.com]

On Monday, September 30, 2019 at 11:47:15 AM UTC-4, et...@whidbey.com wrote:
> My brother's wife wants a small water heater under the kitchen
> sink. Not an instant hot water type but one that holds a couple
> gallons.
> There is a receptacle under the sink but it also powers the
> diswasher. I am concerned that if both the dishwasher and the water
> heater are on at the same time it will pop the breaker.
> I am looking for a device that will allow the water heater to be on
> until the diswasher starts drawing a certain amount of current, at
> which point the power to the heater would be turned off.
> The power to the dishwasher needs to be on all the time, only the
> heater should be switched. A switch for the water heater cannot be
> added. The solution needs to be plug and play and require no input
> from anyone using the diswasher.
> It seems to me that something like this must be available but I
> can't think of what it would be called and my brain is apparently too
> fuzzy this morning to get google to come up with something for me.
> I am willing to build the device myself if need be but a purchased
> product would be better.
> Thanks,
> Eric

Googling "small water heater 120V" I got a bunch of stuff,
here's a 6 gallon one.
https://www.supplyhouse.com/AO-Smith-EJC-6-6-Gallon-ProLine-Compact-Residential-Electric-Water-Heater

Is that what you want?

George H.

[et...@whidbey.com]

It's actually smaller, about two gallons.
Eric

[tabb...@gmail.com]

such demand management is perfectly legal here.

[peterw...@gmail.com]

On Wednesday, October 2, 2019 at 6:58:54 AM UTC-4, tabb...@gmail.com wrote:

> such demand management is perfectly legal here.

The US has three levels of "management" for electrical (and other) devices:

a) The National Electrical Code (NEC): This regulates hard-wired systems and switchgear, and how peripheral devices are connected to the system - such as light fixtures and other devices not plugged in. A hard-wired relay would be considered "switchgear" and therefore covered.

b) UL (Underwriters Laboratory) - this is a 'family' of such bodies, of which UL is the most prevalent: UL regulates those devices that connect to the system above, and has to do with (among many other things) grounding, electrical safety, loading, and so forth. This applies to stand-alone (complete) devices. Note that such devices are "LISTED", not "approved".

c) UR (Recognized): This applies to individual components within a system - such as a relay in a control, or similar. That part does not stand alone. but may be replaceable. So, if one has a UL device of several parts, one fails, then that part *must* be replaced with a UR part to retain the UL listing.

Why it matters: There is this funny thing called "insurance". And if one has property insurance, and reads the fine print, it will refer to things meeting code and being properly inspected and so forth. It will also refer to 'connected devices' or any number of other words for whatever one has to plug into the wall as being "listed".

Should that hand-made relay you are referring to cause a fire and cause damage such that the property owner makes a claim - and should the insurance inspector (and there will be one) determine that the cause was this unlisted/unrecognized device - OOPS! Either the Company will not pay, or if it does, it will then immediately cancel the policy. And the property owner will be quite challenged to get insurance in the future at any reasonable cost.

Nothing that was done was "illegal". And Code Violations are not "illegal".

Just stupid. Something you continue not to understand. And the advice you give continues to suffer for it.

[Fox's Mercantile]

On 10/2/19 7:02 AM, pf...@aol.com wrote:
> Nothing that was done was "illegal". And Code Violations are
> not "illegal".

In Ranger, the code works like this:
"It ain't blowed up yet has it?"
And when it inevitably does:
"Aw man, it blowed up. You must'a doned it wrong."

Neutrals can be 1 or 2 sizes smaller, because, you know, no
current in Neutral or they would have called it something else.

#8 for a water heater? #10 is cheaper. Same reason #14 works
for outlets.

Double breakers with a pin between the handles? Pish tosh, a
pair of singles works just fine, and they DON'T have to be next
to each other.

Run out of wires? Use the bare one for ground and neutral, then
you can use the white one for power.

No ground in the outlet box? No problem tie the neutral and
ground screws together.

And yeah, I'm waiting for my neighbor's house to explode.

[Wolfgang Allinger]

On 30 Sep 19 at group /sci/electronics/repair in article 10b56eb2-75e5-4a4c...@googlegroups.com
<tabb...@gmail.com> (tabb...@gmail.com) wrote:

> On Monday, 30 September 2019 16:47:15 UTC+1, et...@whidbey.com wrote:
>> My brother's wife wants a small water heater under the kitchen
>> sink. Not an instant hot water type but one that holds a couple
>> gallons.
>> There is a receptacle under the sink but it also powers the
>> diswasher. I am concerned that if both the dishwasher and the water
>> heater are on at the same time it will pop the breaker.
>> I am looking for a device that will allow the water heater to be on
>> until the diswasher starts drawing a certain amount of current, at
>> which point the power to the heater would be turned off.
>> The power to the dishwasher needs to be on all the time, only the
>> heater should be switched. A switch for the water heater cannot be
>> added. The solution needs to be plug and play and require no input
>> from anyone using the diswasher.
>> It seems to me that something like this must be available but I
>> can't think of what it would be called and my brain is apparently too
>> fuzzy this morning to get google to come up with something for me.
>> I am willing to build the device myself if need be but a purchased
>> product would be better.
>> Thanks,
>> Eric

> A relay is all you need. Remove the coil & rewind with a small number of
> turns of thick wire. Now when enough current goes to the dishwasher, the
> water heater is turned off. I'd use 2 relays the same, one to experiment,
> the 2nd for the final unit.

No, it wouldn't work. Normal relays working with DC coils. You need a very
special relay designed for AC coils. Very rare and likely expensive.

Contactors exist for AC and DC coils, maybe they work. You need one with
contact type NC i.e. closed for feeding the heater when no current is
drawn from the dishwasher. These NC types are not common too.



Saludos (an alle Vernünftigen, Rest sh. sig)
Wolfgang

--
Ich bin in Paraguay lebender Trollallergiker :) reply Adresse gesetzt!
Ich diskutiere zukünftig weniger mit Idioten, denn sie ziehen mich auf
ihr Niveau herunter und schlagen mich dort mit ihrer Erfahrung! :p
(lt. alter usenet Weisheit) iPod, iPhone, iPad, iTunes, iRak, iDiot

[peterw...@gmail.com]

On Wednesday, October 2, 2019 at 8:47:23 AM UTC-4, Wolfgang Allinger wrote:

> No, it wouldn't work. Normal relays working with DC coils. You need a very
> special relay designed for AC coils. Very rare and likely expensive.

Not rare. But certainly expensive, by a factor of 3 to 5. The difference, at the simplest level, is that the AC-coil relay has two coils (transformer) such that the second is producing current as the first is 'collapsing', thereby holding the contactor in place instead of "chattering". That is, as stated, the simplest description of a not-simple configuration - hence the cost.

https://www.techwalla.com/articles/difference-between-ac-dc-relay-coil

[Ralph Mowery]

In article <20057da5-fcd6-4b84...@googlegroups.com>,
peterw...@gmail.com says...

>
> > No, it wouldn't work. Normal relays working with DC coils. You need a very
> > special relay designed for AC coils. Very rare and likely expensive.
>
> Not rare. But certainly expensive, by a factor of 3 to 5. The difference, at the simplest level, is that the AC-coil relay has two coils (transformer) such that the second is producing current as the first is 'collapsing', thereby holding the contactor in place instead of "chattering". That is, as stated, the simplest
description of a not-simple configuration - hence the cost.
>
> https://www.techwalla.com/articles/difference-between-ac-dc-relay-coil
>
>
> Peter Wieck
> Melrose Park, PA
>
>

BS

They are not rare or is the price that much different.

For example a plug in relay that is almost identical except for the coil
voltage and current As listed in a Mouser catalog.

KRPA-11AG-120 $ 22 120 Volt AC coil 10 amp contacts
KRPA-11DG-24 $ 16 24 Volt DC coil 10 amp contacts.

That so called second coil is really just a thick piece of copper at the
top of the coil. Large AC contactors often have similar pieces of copper
on the laminations.


I worked in a plant that had hundreds if not thousands of relays similar
to those. Part were AC coils and part were DC coils.


Now solid state 'relays' are often used in switching AC circuits off and
on. We used many of those also.

[three_jeeps]

Don't ya just love people who change the invariants of a problem to 'solve' it?

Is there a reason that the hot water heater+tank needs to be under the sink? Would it be possible to mount the heater under the floor under the sink and run a pipe up to the sink? Might allow wiring in a space that is more accessible.

[Rob]

et...@whidbey.com <et...@whidbey.com> wrote:
> My brother's wife wants a small water heater under the kitchen
> sink. Not an instant hot water type but one that holds a couple
> gallons.
> There is a receptacle under the sink but it also powers the
> diswasher. I am concerned that if both the dishwasher and the water
> heater are on at the same time it will pop the breaker.
> I am looking for a device that will allow the water heater to be on
> until the diswasher starts drawing a certain amount of current, at
> which point the power to the heater would be turned off.
> The power to the dishwasher needs to be on all the time, only the
> heater should be switched. A switch for the water heater cannot be
> added. The solution needs to be plug and play and require no input
> from anyone using the diswasher.
> It seems to me that something like this must be available but I
> can't think of what it would be called and my brain is apparently too
> fuzzy this morning to get google to come up with something for me.
> I am willing to build the device myself if need be but a purchased
> product would be better.
> Thanks,
> Eric

They are available here in the Netherlands, and are/were commonly used
to connect a washer and a dryer to a single circuit.
These boxes cover the same situation, where a washing machine consumes
a lot of power during the phase where it heats the water and could trip
the breaker when a dryer which also uses a lot of power is used at the
same time.

I don't know if they are available for the same purpose in the USA.
And also I don't think they would still work so well as it did in the
past, where such household equipment would still have an electromechanical
controller and could reliably be paused by just cutting the line current.
Todays machines with a microprocessor maybe would not handle this so well.
But in your use case (with a close-in heater) that should not be an issue.

[Ralph Mowery]

In article <slrnqp9v0n...@xs9.xs4all.nl>, nom...@example.com
says...

>
> They are available here in the Netherlands, and are/were commonly used
> to connect a washer and a dryer to a single circuit.
> These boxes cover the same situation, where a washing machine consumes
> a lot of power during the phase where it heats the water and could trip
> the breaker when a dryer which also uses a lot of power is used at the
> same time.
>
>

Interisting. I guess where you are at the circuit is around 240 volts
for everything.

Here in the states most washers use 120 volts and the dryers are on the
240 volt circuit. That way they can be ran at the same time as the
wires go back to the breaker box.

I don't know how others do it,but many days my wife will wash 2 or 3
loads of cloths. She will be drying the first load while the 2nd one is
washing to save time.

[tabb...@gmail.com]

On Wednesday, 2 October 2019 13:02:17 UTC+1, pf...@aol.com wrote:

of no relevance to us here in the UK.

[tabb...@gmail.com]

On Wednesday, 2 October 2019 13:47:23 UTC+1, Wolfgang Allinger wrote:
> On 30 Sep 19 at group /sci/electronics/repair in article 10b56eb2-75e5-4a4c...@googlegroups.com

Relays with ac coils are common. Some are called contactors. And relays/contactors with 2 way contacts are also common.


NT

[tabb...@gmail.com]

If it really is just the drier that's the problem, there are better ways to dry things anyway, eg fan & dehumidifier.


NT

[Andy Burns]

tabb...@gmail.com wrote:

> Relays with ac coils are common. Some are called contactors. And relays/contactors with 2 way contacts are also common.

And combinations of current driven relays and contactors are sold to
give priority or non-priority (first come keeps supply) access to
limited power supply, e.g. showers or EV charging

<https://youtu.be/mCeP-rNQTQU>

Or for a more "interesting" presentation style ...

<https://youtu.be/N_jTZbpUfTc>

[whit3rd]

On Monday, September 30, 2019 at 8:47:15 AM UTC-7, et...@whidbey.com wrote:
> My brother's wife wants a small water heater under the kitchen

> sink. ...

> There is a receptacle under the sink but it also powers the
> diswasher. I am concerned that if both the dishwasher and the water
> heater are on at the same time it will pop the breaker.

Breakers (thermal type) can tolerate a short-duration overcurrent, so all you really
need is a low-voltage AC relay, coil in series with... the water heater.

Problem: if it turns off the dishwasher, does the electronic controller forget that
it was in a cycle, or on a timer, and stay OFF? Old dishwasher controls (cam
and motor) would continue after interruption.

Turn it around the other way, and sense current into the dishwasher, turning off
the water heater... but the dishwasher has a complex cycle, not a constant current
at all, how would you know the right current-draw threshold?

It can be done, but running another circuit to the kitchen is easier. While you're
at it, see if 240V heaters are available, the wire won't have to be as heavy...

[Rob]

Here we have 230v line for all purposes (except industrial stuff which
users 3x230v 3-phase, 400v between phases).

The problem would only occur in older installations where there is only
a single circuit of maybe only 10A. Nowadays all circuits in homes
are 230V/16A. So you can use a total of 3.6kW which should be enough,
or else you could have 2 circuits. Main fuse is usually 35A.