Repeatedly blowing thermal fuses on La Pavoni Europiccola converted from 220V

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Dr. Coffee

Postby Dr. Coffee » Jan 04, 2019, 4:00 pm

Hey guys, I've now blown my 3rd thermal fuse on my 2 element europiccola that was converted from 220V. The only remaining 220V electrical component in the machine is the rocker switch that lights up, powers on, and chooses which element to send power to. There's always enough water in the machine. Did I place it wrong? It's in contact with the heating element but still has that red piece of insulation over it.

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redbone

Postby redbone » replying to Dr. Coffee » Jan 04, 2019, 5:05 pm

Pictures of wiring help. Have you tested for continuity? Found this wattage/Volts ++ handy. https://www.rapidtables.com/calc/electric/watt-volt-amp-calculator.html. Suggest further testing using a CGFI power bar.
Between order and chaos there is espresso.
Semper discens.


Rob
LMWDP #549

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homeburrero
Team HB

Postby homeburrero » Jan 04, 2019, 5:07 pm

The 110V element does draw around 9 amps -- twice the amperage that the 220V element draws, but that normally should not cause you to melt the thermal fuse. To be sure, make sure you are using fuses rated for up to 15 amp, and take care to get the fuse nicely crimped and/or soldered to the wire connections. (A bad connection or an underrated fuse might heat up enough to blow based on the current.)
Pat
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jwCrema

Postby jwCrema » Jan 04, 2019, 7:45 pm

I am not clear about your description of your element. What exact element did you install?

Dr. Coffee

Postby Dr. Coffee » Jan 05, 2019, 7:40 pm

homeburrero wrote:The 110V element does draw around 9 amps -- twice the amperage that the 220V element draws, but that normally should not cause you to melt the thermal fuse. To be sure, make sure you are using fuses rated for up to 15 amp, and take care to get the fuse nicely crimped and/or soldered to the wire connections. (A bad connection or an underrated fuse might heat up enough to blow based on the current.)


On further inspection, the crimped area on one end of the new thermal fuse was not crimped well at all, but I can't imagine that I've made that mistake every time.

jwCrema wrote:I am not clear about your description of your element. What exact element did you install?


I installed this heating element:
https://www.theespressoshop.co.uk/en/La ... -4041.aspx

Dr. Coffee

Postby Dr. Coffee » Jan 05, 2019, 7:44 pm

redbone wrote:Pictures of wiring help. Have you tested for continuity? Found this wattage/Volts ++ handy. https://www.rapidtables.com/calc/electric/watt-volt-amp-calculator.html. Suggest further testing using a CGFI power bar.


I'll get a picture in a little bit, but I have tested for continuity of the fuse if thats what you mean, and the fuse is definitely blown

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redbone

Postby redbone » Jan 05, 2019, 8:03 pm

Dr. Coffee wrote:On further inspection, the crimped area on one end of the new thermal fuse was not crimped well at all, but I can't imagine that I've made that mistake every time.


Well Dr. Coffee, a continual mistake like this could result in a malpractice suit. :mrgreen:
Between order and chaos there is espresso.
Semper discens.


Rob
LMWDP #549

Dr. Coffee

Postby Dr. Coffee » replying to redbone » Jan 06, 2019, 11:57 am

Thank god I work for an espresso hospital, they pay for my espresso machine malpractice, but I do want to figure this out - I took an oath

jwCrema

Postby jwCrema » replying to Dr. Coffee » Jan 08, 2019, 8:53 pm

This is a head scratcher. Have you tried the CGFI power bar suggestion?

espresso111

Postby espresso111 » Jan 09, 2019, 3:12 pm

I would agree with the post by homeburrero.

A thermal fuse is designed to blow with excessive heat, not excessive current, but it must still be rated to carry the current drawn by the element. Overrating the current rating of the thermal fuse will ensure that any self-heating due to the current draw will not trigger the fuse. Besides, there is already an electrical fuse to deal with excessive current due to an electrical fault, so overrating the thermal fuse is not a problem.