Greetings,
My wife uses foot baths in her shop and the heaters fail on them. The
style of foot bath she likes best is no longer available. The baths
all seem to be made by the same company, Helen of Troy. Model 61320.
Anyway, I took a couple apart to look at the heaters and they appear
to be ceramic power resistors. They are marked "20W200 ohms" , except
the ohms symbol is used. The foot baths only draw 78 watts and there
is a vibrating doodad inside too. There is a bimetal switch in series
with the resistor. The switches are inside a tube of some sort of heat
resistance woven stuff. Does it make sense that what I think are
ceramic encapsulated power resistors are exactly that? I'm thinking I
should buy a couple and see if they work. I would also like to be able
to replace the bimetal switches and the heat resistant tubing as well
but I don't know what to call the tubing.
Thanks,
Eric

After serious thinking wrote :
Greetings,
My wife uses foot baths in her shop and the heaters fail on them. The
style of foot bath she likes best is no longer available. The baths
all seem to be made by the same company, Helen of Troy. Model 61320.
Anyway, I took a couple apart to look at the heaters and they appear
to be ceramic power resistors. They are marked "20W200 ohms" , except
the ohms symbol is used. The foot baths only draw 78 watts and there
is a vibrating doodad inside too. There is a bimetal switch in series
with the resistor. The switches are inside a tube of some sort of heat
resistance woven stuff. Does it make sense that what I think are
ceramic encapsulated power resistors are exactly that? I'm thinking I
should buy a couple and see if they work. I would also like to be able
to replace the bimetal switches and the heat resistant tubing as well
but I don't know what to call the tubing.
Thanks,
Eric

Eric,
A footbath is a great place to strart a trip thru electrocution to the
morgue.
I there is ever an acident the first place the investigator will look
is who repaired it.

For your own happiness DON'T DO IT. :-?

--
John G

On Mon, 10 Dec 2012 11:06:54 +1100, John G
wrote:

After serious thinking wrote :
Greetings,
My wife uses foot baths in her shop and the heaters fail on them. The
style of foot bath she likes best is no longer available. The baths
all seem to be made by the same company, Helen of Troy. Model 61320.
Anyway, I took a couple apart to look at the heaters and they appear
to be ceramic power resistors. They are marked "20W200 ohms" , except
the ohms symbol is used. The foot baths only draw 78 watts and there
is a vibrating doodad inside too. There is a bimetal switch in series
with the resistor. The switches are inside a tube of some sort of heat
resistance woven stuff. Does it make sense that what I think are
ceramic encapsulated power resistors are exactly that? I'm thinking I
should buy a couple and see if they work. I would also like to be able
to replace the bimetal switches and the heat resistant tubing as well
but I don't know what to call the tubing.
Thanks,
Eric

Eric,
A footbath is a great place to strart a trip thru electrocution to the
morgue.
I there is ever an acident the first place the investigator will look
is who repaired it.

For your own happiness DON'T DO IT. :-?
I thought about that. But there is really no other foot bath that has
the same ease of cleaning and if I replace the resistor wrongly enough
to maybe cause power to enter the water then the circuit breaker and
the GFI woiuld trip. The cleaning is super important. My wife has to
disinfect each foot bath after a client uses it and before another
client can put their feet in it. Fungus infections are particularly
troublesome. My wife has never failed to sterilize her tools and has
never had a client become infected from her shop. So she needs tools
that are easy to sterlize and one thing that makes tools hard to
sterlize are crevices which her current foot baths do not have but
which all the new ones do.
Eric

wrote in
:

On Mon, 10 Dec 2012 11:06:54 +1100, John G
wrote:

After serious thinking wrote :
Greetings,
My wife uses foot baths in her shop and the heaters fail on them.
The style of foot bath she likes best is no longer available. The
baths all seem to be made by the same company, Helen of Troy. Model
61320. Anyway, I took a couple apart to look at the heaters and they
appear to be ceramic power resistors. They are marked "20W200 ohms"
, except the ohms symbol is used. The foot baths only draw 78 watts
and there is a vibrating doodad inside too. There is a bimetal
switch in series with the resistor. The switches are inside a tube
of some sort of heat resistance woven stuff. Does it make sense that
what I think are ceramic encapsulated power resistors are exactly
that? I'm thinking I should buy a couple and see if they work. I
would also like to be able to replace the bimetal switches and the
heat resistant tubing as well but I don't know what to call the
tubing. Thanks,
Eric

Eric,
A footbath is a great place to strart a trip thru electrocution to the
morgue.
I there is ever an acident the first place the investigator will look
is who repaired it.

For your own happiness DON'T DO IT. :-?
I thought about that. But there is really no other foot bath that has
the same ease of cleaning and if I replace the resistor wrongly enough
to maybe cause power to enter the water then the circuit breaker and
the GFI woiuld trip. The cleaning is super important. My wife has to
disinfect each foot bath after a client uses it and before another
client can put their feet in it. Fungus infections are particularly
troublesome. My wife has never failed to sterilize her tools and has
never had a client become infected from her shop. So she needs tools
that are easy to sterlize and one thing that makes tools hard to
sterlize are crevices which her current foot baths do not have but
which all the new ones do.
Eric


I assume you are in 120V land!

A simple calculation (P=(V^2)/R) shows the resistor probably dissipates
72 watts which would correspond neatly with your observed 78W draw.
However the originals are only rated for 20W - no wonder they fail!

You do not know what extra testing has been done by "Helen of Troy" to
qualify these resistors for use at 3.6 times their rating, nor do you
know if a third party's 20W 200 ohm resistor will fail safe.

If you had appropriate professional liability insurance for small
medical appliance repair you would run away screaming from a customer
who asked you to fix a device that overran a heater by that high a
factor using unapproved parts.

The fact that you belive the GFI can be relied on to backstop your
possible shoddy workmanship means I can be certain that you are not a
fit and competent person to repair these appliances.

Basically you are putting all your assets on the line. Your home, your
wife's business etc. and because she let you work on them, she's
negligent as well if they are ever put back into service.

Find a company willing to repair them (if you can) and make sure they
have appropriate insurance or forget about it. --
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL

"Ian Malcolm"


I assume you are in 120V land!

A simple calculation (P=(V^2)/R) shows the resistor probably dissipates
72 watts which would correspond neatly with your observed 78W draw.
However the originals are only rated for 20W - no wonder they fail!


** The 20W resistor is mounted on a heatsink (ie the tub of water) so can
dissipate far more than its free air rating.

BTW: the " Helen of Troy Model 61320" is sold to the public and retails for
about US $40.

The OP's main problem will be finding an exact match that fits tightly in
whatever clamp holds it up against the tub.

But I agree, the safety issue is critical and repair is not advisable nor
even economic.


..... Phil

wrote in message
...
Greetings,
My wife uses foot baths in her shop and the heaters fail on them. The
style of foot bath she likes best is no longer available. The baths
all seem to be made by the same company, Helen of Troy. Model 61320.
Anyway, I took a couple apart to look at the heaters and they appear
to be ceramic power resistors. They are marked "20W200 ohms" , except
the ohms symbol is used. The foot baths only draw 78 watts and there
is a vibrating doodad inside too. There is a bimetal switch in series
with the resistor. The switches are inside a tube of some sort of heat
resistance woven stuff. Does it make sense that what I think are
ceramic encapsulated power resistors are exactly that? I'm thinking I
should buy a couple and see if they work. I would also like to be able
to replace the bimetal switches and the heat resistant tubing as well
but I don't know what to call the tubing.
Thanks,
Eric

What form does the double? insulation take between resistors and water?

In the extended SI system of units
The unit of beauty is the milliHelen - the amount of beauty required to
launch one ship

On 09/12/2012 22:52, wrote:
Greetings,
My wife uses foot baths in her shop and the heaters fail on them. The
style of foot bath she likes best is no longer available. The baths
all seem to be made by the same company, Helen of Troy. Model 61320.
Anyway, I took a couple apart to look at the heaters and they appear
to be ceramic power resistors. They are marked "20W200 ohms" , except
the ohms symbol is used. The foot baths only draw 78 watts and there
is a vibrating doodad inside too. There is a bimetal switch in series
with the resistor. The switches are inside a tube of some sort of heat
resistance woven stuff. Does it make sense that what I think are
ceramic encapsulated power resistors are exactly that? I'm thinking I
should buy a couple and see if they work. I would also like to be able
to replace the bimetal switches and the heat resistant tubing as well
but I don't know what to call the tubing.
Thanks,
Eric


You have to be careful with those things.

SWMBO and I bought a heated massaging foot bath for her mother (in her
eighties), who we heard one day telling her friends that she now had an
infra-red vibrator...
--
Peter

On Mon, 10 Dec 2012 02:04:06 +0000 (UTC), Ian Malcolm
put finger to keyboard and
composed:

I assume you are in 120V land!

A simple calculation (P=(V^2)/R) shows the resistor probably dissipates
72 watts which would correspond neatly with your observed 78W draw.
However the originals are only rated for 20W - no wonder they fail!

You do not know what extra testing has been done by "Helen of Troy" to
qualify these resistors for use at 3.6 times their rating, nor do you
know if a third party's 20W 200 ohm resistor will fail safe.

I'd like to see how these appliances behave if you operate them
without a water load. Do they actually sense the presence of water
and, if not, is the bimetallic switch able to prevent damage to the
resistor in the absence of cooling?

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

On Tue, 11 Dec 2012 08:14:54 +1100, Franc Zabkar
wrote:

On Mon, 10 Dec 2012 02:04:06 +0000 (UTC), Ian Malcolm
put finger to keyboard and
composed:

I assume you are in 120V land!

A simple calculation (P=(V^2)/R) shows the resistor probably dissipates
72 watts which would correspond neatly with your observed 78W draw.
However the originals are only rated for 20W - no wonder they fail!

You do not know what extra testing has been done by "Helen of Troy" to
qualify these resistors for use at 3.6 times their rating, nor do you
know if a third party's 20W 200 ohm resistor will fail safe.

I'd like to see how these appliances behave if you operate them
without a water load. Do they actually sense the presence of water
and, if not, is the bimetallic switch able to prevent damage to the
resistor in the absence of cooling?

- Franc Zabkar
Yes Franc, there is a bimetal switch in series with the resistor and
it lays along the length of the resistor.
Eric

On Dec 10, 5:13*pm, wrote:
On Tue, 11 Dec 2012 08:14:54 +1100, Franc Zabkar





wrote:
On Mon, 10 Dec 2012 02:04:06 +0000 (UTC), Ian Malcolm
put finger to keyboard and
composed:

I assume you are in 120V land!

A simple calculation (P=(V^2)/R) shows the resistor probably dissipates
* 72 watts which would correspond neatly with your observed 78W draw..
However the originals are only rated for 20W *- no wonder they fail!

You do not know what extra testing has been done by "Helen of Troy" to
qualify these resistors for use at 3.6 times their rating, nor do you
know if a third party's 20W 200 ohm resistor will fail safe.

I'd like to see how these appliances behave if you operate them
without a water load. Do they actually sense the presence of water
and, if not, is the bimetallic switch able to prevent damage to the
resistor in the absence of cooling?

- Franc Zabkar

Yes Franc, there is a bimetal switch in series with the resistor and
it lays along the length of the resistor.
Eric- Hide quoted text -

- Show quoted text -

What everyone else says about liability I second. But, is there a 3-
wire or a 2-wire power cord, is the basin metal or plastic, two
zillion things you haven't told us about!!!!

"hr(bob) "


What everyone else says about liability I second. But, is there a 3-
wire or a 2-wire power cord, is the basin metal or plastic, two
zillion things you haven't told us about!!!!


** The basin has to be metal for the resistor / heater idea to work.

The combination of metal basin, mains power and contact heater means it has
to be earthed at the supply.

Stainless steel jugs and kettles are earthed via the lead.


..... Phil

hr(bob) used his keyboard to write :
On Dec 10, 5:13*pm, wrote:
On Tue, 11 Dec 2012 08:14:54 +1100, Franc Zabkar





wrote:
On Mon, 10 Dec 2012 02:04:06 +0000 (UTC), Ian Malcolm
put finger to keyboard and
composed:

I assume you are in 120V land!

A simple calculation (P=(V^2)/R) shows the resistor probably dissipates
* 72 watts which would correspond neatly with your observed 78W draw.
However the originals are only rated for 20W *- no wonder they fail!
You do not know what extra testing has been done by "Helen of Troy" to
qualify these resistors for use at 3.6 times their rating, nor do you
know if a third party's 20W 200 ohm resistor will fail safe.
I'd like to see how these appliances behave if you operate them
without a water load. Do they actually sense the presence of water
and, if not, is the bimetallic switch able to prevent damage to the
resistor in the absence of cooling?

- Franc Zabkar

Yes Franc, there is a bimetal switch in series with the resistor and
it lays along the length of the resistor.
Eric- Hide quoted text -

- Show quoted text -

What everyone else says about liability I second. But, is there a 3-
wire or a 2-wire power cord, is the basin metal or plastic, two
zillion things you haven't told us about!!!!

Does not really matter, any unlicensed repair will void the warrentee
and responsibility will fall RIGHT ON :-? the repairer.

--
John G

"John G"

What everyone else says about liability I second. But, is there a 3-
wire or a 2-wire power cord, is the basin metal or plastic, two
zillion things you haven't told us about!!!!

Does not really matter, any unlicensed repair will void the warrentee and
responsibility will fall RIGHT ON :-? the repairer.


** What "license" is needed to repair such an appliance ????

BTW The maker's warranty must have long ago expired because the unit was
being used commercially.



..... Phil

on 11/12/2012, Phil Allison supposed :
"John G"

What everyone else says about liability I second. But, is there a 3-
wire or a 2-wire power cord, is the basin metal or plastic, two
zillion things you haven't told us about!!!!

Does not really matter, any unlicensed repair will void the warrentee and
responsibility will fall RIGHT ON :-? the repairer.


** What "license" is needed to repair such an appliance ????

BTW The maker's warranty must have long ago expired because the unit was
being used commercially.



.... Phil

I suppose Authorised would be a better word but whatever the risk will
go with the repairer.
And Warranty, of course you are right, but if it was ever properly
tested, UL CE or whatever applies in the location will be void.

--
John G

"John G"
Phil Allison supposed :
"John G"

What everyone else says about liability I second. But, is there a 3-
wire or a 2-wire power cord, is the basin metal or plastic, two
zillion things you haven't told us about!!!!

Does not really matter, any unlicensed repair will void the warrentee
and responsibility will fall RIGHT ON :-? the repairer.


** What "license" is needed to repair such an appliance ????

BTW The maker's warranty must have long ago expired because the unit
was being used commercially.


I suppose Authorised would be a better word but whatever the risk will go
with the repairer.


** Repairers are ALWAYS responsible for making sure an appliance is safe
to use when returned to the owner - or else they must disable it. Nothing
new or different here.

Anecdote:

Yamaha made powered mixing desks that were "double insulated" - the EMX
series.

Several of them came my way with the complaint that performers were
receiving small electric shocks (bites) on the lips from microphones when
using these desks. The reason was simply that there was no earth and the
chassis floated up to half the AC supply voltage and with a few hundred pF
capacitance to ground.

The only answer was to fit a 3 core lead and remove the double square
symbol. The service manual showed that US and Canadian versions were fully
earthed, as no doubt UL and CSA had insisted.

These models were inherently unsafe in live performance situations, if I had
simply done NOTHING then I could have been liable for any injuries that
subsequently occurred.


.... Phil

"Phil Allison" wrote:
"John G"
Phil Allison supposed :
"John G"

What everyone else says about liability I second. But, is there a 3-
wire or a 2-wire power cord, is the basin metal or plastic, two
zillion things you haven't told us about!!!!

Does not really matter, any unlicensed repair will void the warrentee
and responsibility will fall RIGHT ON :-? the repairer.


** What "license" is needed to repair such an appliance ????

BTW The maker's warranty must have long ago expired because the unit
was being used commercially.


I suppose Authorised would be a better word but whatever the risk will go
with the repairer.


** Repairers are ALWAYS responsible for making sure an appliance is safe
to use when returned to the owner - or else they must disable it. Nothing
new or different here.

Anecdote:

Yamaha made powered mixing desks that were "double insulated" - the EMX
series.

Several of them came my way with the complaint that performers were
receiving small electric shocks (bites) on the lips from microphones when
using these desks. The reason was simply that there was no earth and the
chassis floated up to half the AC supply voltage and with a few hundred pF
capacitance to ground.

The only answer was to fit a 3 core lead and remove the double square
symbol. The service manual showed that US and Canadian versions were fully
earthed, as no doubt UL and CSA had insisted.

These models were inherently unsafe in live performance situations, if I had
simply done NOTHING then I could have been liable for any injuries that
subsequently occurred.


... Phil

I keep wanting to pull out my foot bath massage unit, which I think had a
heater. I think I gave it away.. That old plastic stuff tended to crack
open.

At work one time, they built a heated live heart transporter mostly out of
plexiglass. They were testing it and kept blowing the hospital outlet GFI.
I think it was to be used in a helicopter. I suggested installing a
transformer to isolate. It worked.

Greg

On Mon, 10 Dec 2012 19:18:10 -0800 (PST), "hr(bob) "
wrote:

On Dec 10, 5:13*pm, wrote:
On Tue, 11 Dec 2012 08:14:54 +1100, Franc Zabkar





wrote:
On Mon, 10 Dec 2012 02:04:06 +0000 (UTC), Ian Malcolm
put finger to keyboard and
composed:

I assume you are in 120V land!

A simple calculation (P=(V^2)/R) shows the resistor probably dissipates
* 72 watts which would correspond neatly with your observed 78W draw.
However the originals are only rated for 20W *- no wonder they fail!

You do not know what extra testing has been done by "Helen of Troy" to
qualify these resistors for use at 3.6 times their rating, nor do you
know if a third party's 20W 200 ohm resistor will fail safe.

I'd like to see how these appliances behave if you operate them
without a water load. Do they actually sense the presence of water
and, if not, is the bimetallic switch able to prevent damage to the
resistor in the absence of cooling?

- Franc Zabkar

Yes Franc, there is a bimetal switch in series with the resistor and
it lays along the length of the resistor.
Eric- Hide quoted text -

- Show quoted text -

What everyone else says about liability I second. But, is there a 3-
wire or a 2-wire power cord, is the basin metal or plastic, two
zillion things you haven't told us about!!!!
The cord is 3 wire. Everything is properly grounded.
Eric