On Feb 7, 10:54 am, Smitty Two wrote:
In article
,
"Seán O'Leathlóbhair" wrote:



On Feb 7, 2:28 am, Smitty Two wrote:
In article
,
"Seán O'Leathlóbhair" wrote:

Surely
there are not two simultaneous faults: the element dying and something
wrong in the controller?

I'd be suspect of the test results. The slightest corrosion on a test
lead or the DUT can cause gross errors.

Thanks.

A possibility of course but touching the meter leads together reads a
fraction of an Ohm or zero if pressed firmly together. It also r
reads zero when I check the cut-outs. It is a fairly cheap (not dirt
cheap) digital multi-meter and I doubt that it is very accurate but I
don't expect that it will mistake 0 and infinity.

The terminals of the heater element seem nice and clean. So clean
that I did not think of cleaning them up but I will do that to be
sure.

--
Sean Ó Leathlobhair

Mistaking zero and infinity is a common meter problem, due to corrosion
as I suggested. If the meter probes are clean, what about the
connections on the machine? You're looking at a heating circuit; heating
tends to oxidize metals. Did you scrape them with an x-acto or similar?
The only reason I'm being a pest about this is that I agree with you
that it doesn't seem reasonable in this case that you have double
trouble. I'd also run a cheater cord from the wall to the heater element
as a verification test.

Also double-check the voltage scale on the meter by probing
the mains directly. Reconfirm the reading at the element
terminals once you're convinced the meter is working correctly.
Try the lightbulb test as well - perhaps the controller has a
current sensing feature that shuts down the voltage if the
element is open or one side shorted to earth (for the latter,
that would explain why there's no breaker trip).

TM