Older multi temp kettle was cutting out at 50C, further investigation
showed out it was the relay coil going open circuit when it got hot. As
it cooled down it worked again.
Not that uncommon a failure mode for a relay but what surprised me was
that the tiny sub miniature type they've fitted in the kettle itself can
switch 3KW and deal with the inrush current, but obviously it can

This design has all the 'lectronics in the kettle itself, I see the new
ones have them in the base, maybe they have a larger relay

Lee pretended :
Older multi temp kettle was cutting out at 50C, further investigation showed
out it was the relay coil going open circuit when it got hot. As it cooled
down it worked again.
Not that uncommon a failure mode for a relay but what surprised me was that
the tiny sub miniature type they've fitted in the kettle itself can switch
3KW and deal with the inrush current, but obviously it can

The inrush current will be minimal, a kettle element is resistive
rather than inductive.

On 07/06/2017 14:47, Harry Bloomfield wrote:
Lee pretended :
Older multi temp kettle was cutting out at 50C, further investigation
showed out it was the relay coil going open circuit when it got hot.
As it cooled down it worked again.
Not that uncommon a failure mode for a relay but what surprised me was
that the tiny sub miniature type they've fitted in the kettle itself
can switch 3KW and deal with the inrush current, but obviously it can

The inrush current will be minimal, a kettle element is resistive rather
than inductive.

Yes, but I was thinking the cold resistance would be much lower than hot.
But it seems that these printed elements don't have a huge difference
so you are right anyway

Lee

Lee wrote:
On 07/06/2017 14:47, Harry Bloomfield wrote:
Lee pretended :
Older multi temp kettle was cutting out at 50C, further investigation
showed out it was the relay coil going open circuit when it got hot.
As it cooled down it worked again.
Not that uncommon a failure mode for a relay but what surprised me was
that the tiny sub miniature type they've fitted in the kettle itself
can switch 3KW and deal with the inrush current, but obviously it can

The inrush current will be minimal, a kettle element is resistive rather
than inductive.

Yes, but I was thinking the cold resistance would be much lower than hot.
But it seems that these printed elements don't have a huge difference
so you are right anyway

I doubt it, it's not like an incandescent lamp. I'd expect the
resistance to be the same within a couple of percent from cold to hot.

--
Chris Green
·

On Wed, 7 Jun 2017 14:33:21 +0100, Lee
wrote:

Older multi temp kettle was cutting out at 50C, further investigation
showed out it was the relay coil going open circuit when it got hot. As
it cooled down it worked again.
Not that uncommon a failure mode for a relay but what surprised me was
that the tiny sub miniature type they've fitted in the kettle itself can
switch 3KW and deal with the inrush current, but obviously it can

This design has all the 'lectronics in the kettle itself, I see the new
ones have them in the base, maybe they have a larger relay

AC resistive loads are the easiest types to switch.

On Wednesday, 7 June 2017 15:55:28 UTC+1, Caecilius wrote:
On Wed, 7 Jun 2017 14:33:21 +0100, Lee
wrote:

Older multi temp kettle was cutting out at 50C, further investigation
showed out it was the relay coil going open circuit when it got hot. As
it cooled down it worked again.
Not that uncommon a failure mode for a relay but what surprised me was
that the tiny sub miniature type they've fitted in the kettle itself can
switch 3KW and deal with the inrush current, but obviously it can

This design has all the 'lectronics in the kettle itself, I see the new
ones have them in the base, maybe they have a larger relay

AC resistive loads are the easiest types to switch.

even easier if you only want it to last a year. OP you replaced the relay?


NT

On 07/06/2017 22:35, wrote:


even easier if you only want it to last a year. OP you replaced the relay?


I replaced the original (Chinese) 17A with the closest Omron I could
find, which is 16A @250VAC

The original lasted 5yrs in daily use. Wonder if this one will outlast
old age getting to the rest of the kettle