Short or no short?

So, having listened to all the stuff, it seems to me that there are some
implications.

Firstly, a wire has opened. According to what I gather the signature of the
event, there was a current spike prior to the open circuit condition.

I understand that this probably means that a short occurred, then the point
of weakness failed due to the short.

In my experience, this point is most likely to be in the motor itself. We
also see that temperatures did not vastly alter, which is good, as it would
appear that the failure was pretty benign. I'd suggest though that if the
thinnest wire is rated at 6 amps, and something failed at a point well below
this, that this in itself could be a worry, as it may show a possible weak
link, but all should be well, if the system works as normal.

One implication I never heard questioned was thatas I understand it, at
least through launch, the phase is going to be isolated, but in addition to
the motor and the sensor, this will run the other pump in the cell on two
phases. OK, so this has been tested as well, and is OK, but it does sound a
bit vague, ie, are they intending to put it back on after launch?

I imagine this is because of what I mentioned in my last post, ie, if a wire
is slapping about, you do not want it live!

Of course as the motors do still need to do the same amount of work, you
have to draw more current through the remaining windings, and as nothing
untoward has occurred in this mode, I imagine it is a great confidence
boost, as if there were similar problems in these circuits, it would have
shown up, one imagines.

It will be interesting to see how this actually works.

Brian

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Brian Gaff -
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in the display name may be lost.

Just to clarify, I feel there was not a short, more likely the current
pulse on the startup of the pump motor, as activated by the control system
finally made the wire fail somewhere.

Brian

--
Brian Gaff -
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in the display name may be lost.
"Brian Gaff" wrote in message
k...
So, having listened to all the stuff, it seems to me that there are some
implications.

Firstly, a wire has opened. According to what I gather the signature of
the event, there was a current spike prior to the open circuit condition.

I understand that this probably means that a short occurred, then the
point of weakness failed due to the short.

In my experience, this point is most likely to be in the motor itself. We
also see that temperatures did not vastly alter, which is good, as it
would appear that the failure was pretty benign. I'd suggest though that
if the thinnest wire is rated at 6 amps, and something failed at a point
well below this, that this in itself could be a worry, as it may show a
possible weak link, but all should be well, if the system works as normal.

One implication I never heard questioned was thatas I understand it, at
least through launch, the phase is going to be isolated, but in addition
to the motor and the sensor, this will run the other pump in the cell on
two phases. OK, so this has been tested as well, and is OK, but it does
sound a bit vague, ie, are they intending to put it back on after launch?

I imagine this is because of what I mentioned in my last post, ie, if a
wire is slapping about, you do not want it live!

Of course as the motors do still need to do the same amount of work, you
have to draw more current through the remaining windings, and as nothing
untoward has occurred in this mode, I imagine it is a great confidence
boost, as if there were similar problems in these circuits, it would have
shown up, one imagines.

It will be interesting to see how this actually works.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.