Simple Question about Thermal Cutoff (tco) & Fuses

[j barnes]

I have a samovar (an electric tea kettle) with a bad thermal cut off fuse that runs immediately after the 120v input plug The TCO is rated at 4amp and 152C. I cannot locate this fuse anywhere but here:

http://www.gift-centre.com/store/product/7450/Samovar-Fuse-SSFCHW-E4A00/

$30 seems awfully steep for this part.

Would it be safe for me to replace the 4AMP TCO with a 10amp 152C and simply add a 4amp fuse immediately before or after the TCO? Intuitively this seems like it would work, more than 152C the TCO burns, more than 4amps the other fuse blows.

Thanks!

 

[Phil Allison]

"j barnes"

Would it be safe for me to replace the 4AMP TCO with a 10amp 152C

** Yes.

The amp rating is not important long as it is more than 4.



..... Phil

 

[Fred McKenzie]

In article
<65201db0-66d6-46b9-be6d-67de7495aed7@glegroupsg2000goo.googlegroups.com

,
j barnes <slywinking@gmail.com> wrote:

Would it be safe for me to replace the 4AMP TCO with a 10amp 152C and simply
add a 4amp fuse immediately before or after the TCO?

JB-

I can't imagine the tea kettle cost much over $30, so it is not cost
effective to buy the exact part. The price appears to be calculated to
encourage you to buy a new samovar instead of repairing yours.

From where did you obtain the specifications for the original part?
What are the samovar's electrical ratings for voltage and power? They
may be on the bottom or next to the electrical wire.

Several coffee makers I checked all use power in the 600 to 800 watt
range. If the samovar operates close to 480 watts (4 Amperes at 120
Volts), you would not want the fuse to blow at 4 Amperes. I suspect the
function of the original part was to protect against a fire when the pot
was operated after all the liquid had boiled away. So the 4 Ampere
rating is a maximum operating current, not necessarily the current at
which it blows.

How were you going to install the replacement? Soldering is not a good
idea. Solder could melt under normal operating conditions, and
soldering might damage the TCO if you aren't careful. Crimping is the
better approach, but it is difficult to get a good crimp with solid
wires. Some TCOs come with a "crimping ferrule". It is a small metal
tube (brass?) that you insert two wires into and crimp them together.

Fred

 

[Phil Allison]

"Fred McKenzie"

Several coffee makers I checked all use power in the 600 to 800 watt
range. If the samovar operates close to 480 watts (4 Amperes at 120
Volts), you would not want the fuse to blow at 4 Amperes. I suspect the
function of the original part was to protect against a fire when the pot
was operated after all the liquid had boiled away. So the 4 Ampere
rating is a maximum operating current, not necessarily the current at
which it blows.

** The 4 amp rating is mostly to do with the tripping temperature - up to
4 amps of current can pass without changing the tripping temp by more than a
few degrees due to self heating.

IOW, at 4 amps there is only a few degrees C rise in the temp of the
device.

Similarly for the 10 amp types.


..... Phil

 

[DarkwaterBlight]

On Jan 17, 6:43 pm, j barnes <slywink...@gmail.com> wrote:

I have a samovar (an electric tea kettle) with a bad thermal cut off fuse that runs immediately after the 120v input plug  The TCO is rated at 4amp and 152C.  I cannot locate this fuse anywhere but here:

http://www.gift-centre.com/store/product/7450/Samovar-Fuse-SSFCHW-E4A00/

$30 seems awfully steep for this part.

Would it be safe for me to replace the 4AMP TCO with a 10amp 152C and simply add a 4amp fuse immediately before or after the TCO?  Intuitively this seems like it would work,  more than 152C the TCO burns, more than 4amps the other fuse blows.

Thanks!

A 22QBP152 is the same part and retails for about $7

 

[Phil Allison]

"nesesu"
"Phil Allison"

"j barnes"

Would it be safe for me to replace the 4AMP TCO with a 10amp 152C

** Yes.

The amp rating is not important long as it is more than 4.

FWIW, I have delved into several of my wife's sewing appliances that
were originally designed for European countries and they seem to
forget the current issue in adapting from 240V to 120V for the NA
market. Her two irons both failed from the overtemperature safety
cutout [self resetting thermal breaker] contacts burning, even through
the cutout should never have tripped.


** The device in question here is a "one shot" thermal fuse.

There are no contacts inside.


I cannot see a Samovar taking much less than 1000-1200watts, like most
kettles, so I would, myself, use a 10A rated cutout. Naturally, when
installing it, it is best to crimp the connections or spot weld but,
in any case, you must wrap the new one time thermal fuse in a wet rag
to keep it cool while attaching it.

** Hardly necessary if you crimp the wires - and anyone with reasonable
soldering skills can solder the lead ends quickly without heating the body
to 152C.



...... Phil

 

[nesesu]

On Jan 17, 6:05 pm, "Phil Allison" <phi...@tpg.com.au> wrote:

"j barnes"

Would it be safe for me to replace the 4AMP TCO with a 10amp 152C

** Yes.

 The amp rating is not important long as it is more than 4.

....  Phil

FWIW, I have delved into several of my wife's sewing appliances that
were originally designed for European countries and they seem to
forget the current issue in adapting from 240V to 120V for the NA
market. Her two irons both failed from the overtemperature safety
cutout [self resetting thermal breaker] contacts burning, even through
the cutout should never have tripped. They were rated for 6A and the
irons draw about 12A at 120V. In both cases the cutout is spot welded
to the base assembly and not replaceable. New plate $85.
Similar with the old foot controllers for sewing machines where the
contacts look to have ample voltage clearances, but marginal contact
area. One Bernina has actually burnt one contact half away over the
last 50 odd years.
I cannot see a Samovar taking much less than 1000-1200watts, like most
kettles, so I would, myself, use a 10A rated cutout. Naturally, when
installing it, it is best to crimp the connections or spot weld but,
in any case, you must wrap the new one time thermal fuse in a wet rag
to keep it cool while attaching it.

Neil S.

 

[Jim Yanik]

Fred McKenzie <fmmck@aol.com> wrote in
news:fmmck-007CC7.23000717012011@5ad64b5e.bb.sky.com:

In article
65201db0-66d6-46b9-be6d-67de7495aed7@glegroupsg2000goo.googlegroups.com
,
j barnes <slywinking@gmail.com> wrote:

Would it be safe for me to replace the 4AMP TCO with a 10amp 152C and
simply add a 4amp fuse immediately before or after the TCO?

JB-

I can't imagine the tea kettle cost much over $30, so it is not cost
effective to buy the exact part. The price appears to be calculated
to encourage you to buy a new samovar instead of repairing yours.

From where did you obtain the specifications for the original part?
What are the samovar's electrical ratings for voltage and power? They
may be on the bottom or next to the electrical wire.

Several coffee makers I checked all use power in the 600 to 800 watt
range. If the samovar operates close to 480 watts (4 Amperes at 120
Volts), you would not want the fuse to blow at 4 Amperes. I suspect
the function of the original part was to protect against a fire when
the pot was operated after all the liquid had boiled away. So the 4
Ampere rating is a maximum operating current, not necessarily the
current at which it blows.

How were you going to install the replacement? Soldering is not a
good idea. Solder could melt under normal operating conditions, and
soldering might damage the TCO if you aren't careful. Crimping is the
better approach, but it is difficult to get a good crimp with solid
wires. Some TCOs come with a "crimping ferrule". It is a small metal
tube (brass?) that you insert two wires into and crimp them together.

Fred

I have a Presto Fry Granddaddy deep fryer that the TCO blew when the
bimetal thermostat contacts welded together. AFAIK,they don't make the
Grandaddy anymore,so I unstuck and filed the contacts,then bought a new TCO
at Radio Shack !! that was a few deg C lower than the original,but same
current rating.It's been working fine ever since. I bought new crimp
ferrules at Skycraft Surplus.(local store,Orlando,FL.!)

--
Jim Yanik
jyanik
at
localnet
dot com

 

[j barnes]

On Jan 18, 6:19 pm, Jim Yanik <jya...@abuse.gov> wrote:

Fred McKenzie <fm...@aol.com> wrote innews:fmmck-007CC7.23000717012011@5ad64b5e.bb.sky.com:









In article
65201db0-66d6-46b9-be6d-67de7495a...@glegroupsg2000goo.googlegroups.com
,
 j barnes <slywink...@gmail.com> wrote:

Would it be safe for me to replace the 4AMPTCOwith a 10amp 152C and
simply add a 4ampfuseimmediately before or after theTCO?

JB-

I can't imagine the tea kettle cost much over $30, so it is not cost
effective to buy the exact part.  The price appears to be calculated
to encourage you to buy a new samovar instead of repairing yours.

From where did you obtain the specifications for the original part?  
What are the samovar's electrical ratings for voltage and power?  They
may be on the bottom or next to the electrical wire.

Several coffee makers I checked all use power in the 600 to 800 watt
range.  If the samovar operates close to 480 watts (4 Amperes at 120
Volts), you would not want thefuseto blow at 4 Amperes.  I suspect
the function of the original part was to protect against a fire when
the pot was operated after all the liquid had boiled away.  So the 4
Ampere rating is a maximum operating current, not necessarily the
current at which it blows.

How were you going to install the replacement?  Soldering is not a
good idea.  Solder could melt under normal operating conditions, and
soldering might damage theTCOif you aren't careful.  Crimping is the
better approach, but it is difficult to get a good crimp with solid
wires.  Some TCOs come with a "crimping ferrule".  It is a small metal
tube (brass?) that you insert two wires into and crimp them together.

Fred

I have a Presto Fry Granddaddy deep fryer that theTCOblew when the
bimetal thermostat contacts welded together. AFAIK,they don't make the
Grandaddy anymore,so I unstuck and filed the contacts,then bought a newTCO
at Radio Shack !! that was a few deg C lower than the original,but same
current rating.It's been working fine ever since. I bought new crimp
ferrules at Skycraft Surplus.(local store,Orlando,FL.!)

--
Jim Yanik
jyanik
at
localnet
dot com

Thank you everyone for all the helpful advice and suggestions! I'm
glad everyone reminded me to crimp rather than solder. I can be a
real space case when I get caught up in repairs so it was a great
reminder.

For the curious, the $30 part is for a $170+ Samovar so I don't think
they are trying to force a new sale. It is hoity-toity expensive
German made samovar used for shi-shi-fu-fu parties. Looking at the
thing, I would have never guessed somebody would pay so much for it.
I'm certain it cost a fraction of what it sold for to make it and
there were dozens of happy people along the chain of sale between
Germany and here who tacked on a nice healthy profit for themselves.

Personally, I'm the kind of dude who would bust out with my trusty
decades old plastic coffee-stained Mr. Coffee or my newer Proctor
Silex tea kettle if I need quick boiling water, if my friends don't
respect me because of that they aren't my friends. However, this is
the female species I am dealing with here. Such uncouthness as mine
displayed by the hostess who is requesting the repair would bring many
years of shame and embarrassment on her family for generations to
come.

Of course I'm just kidding about the shame and embarrassment lasting
for generations, but this repair is bound up in culture and psuedo-
sophistication rather than pure utility.

Thanks again!