[Nut-upsuser] MGE Ellipse 800 shutdown problems

[Arjen de Korte]

>> The 'ondelay' timer will be started at the same time as the 'offdelay'
>> timer and is really only meant to provide a means to prevent a deadlock
>> when the power returns before the UPS shuts down. The better solution is
>> documented in 'docs/shutdown.txt' which you have been told to read on
>> several occasions already.
> It means that this is not the mean setting of "ups.delay.start" parameter
> of UPS?

Indeed.

> This delay not only could help on deadlock situation, but also
> gives time for battery recharge and save the system about spuriouse line
> instability which I have seen here (similar to prell).

Since these timers are notoriously unreliable (not just for your UPS, but
in general), the better solution would be to follow what is documented in
the aforementioned document. The best solution however, would be to have a
proper indication of the *real* charge state of the batteries. In that
case, it can switch on the outlets when the charge is above the critical
minimum that is needed to startup and shutdown the systems connected to it
if the mains fails right after powering up them again. Newer MGE units
(like the Evolution range for instance) will provide such functionality.

[...]

>>> I modified this row with a small function, where I tries start driver 5
>>> times - to be save.
>> This should not be needed, a driver should retry by itself
> BUT IT IS NOT!

I know (there is no need to shout). That's why I asked if this happened
with 'newmge-shut' too as I don't think it is worth to fix 'mge-shut' in
this aspect, since it will be replaced anyway in the not so distant
future.

[...]

>> I very much question your last remark. You can build excellent UPS'es
>> without microcontrollers and just good old trusty NE555's. The fact that
>> this doesn't happen anymore is because we can do this cheaper and more
>> flexible with microcontrollers than with analog timers nowadays. But it
>> can be done.
> I'm an old man in this profession, analog circuits has many, many seriouse
> problems (need manual tunning, using large electrolitical or tantal based
> capacitors - timings up to several minutes - this are crucial for
> prodaction of reasonably large series).

As a Senior Electrical Designer I'm an old dog in the electronics industry
myself too. Counters have been available for decades, which could easily
remove the need for large capacitors and resistors to achieve long delay
times for instance. My point is that the fact that something is not put
into a microcontroller doesn't mean the circuit isn't engineered properly.

> I do not explore what for used NE555 but I think it work here only as a
> cheep comparator.

Again, I fail to see what's wrong with that.

[...]

> Are you kidding, where you can get same batteries and how much those will
> cost?

I can't read it, but I suspect that somewhere on the site

    http://www.mgeups.hu/

there will be a dealer locator that will be able to provide you with
replacement batteries for your MGE UPS unit.

> - now days 3-4 years means that everythinbg is changed, you can not
> by same thing again.

Sure you can, it all depends who you're doing business with. In the
company I work for (not being MGE), we provide full support for the stuff
we design, make and sell for at least 12 years after delivery. If that
means we have to stock components that have become obsolete, that's our
problem.

> Batteries are also always "improved", and nobody care
> about old models - "the new should be good". Of course I could by a new
> UPS, but what would be changed to me?

Well, to comment on the last part, see above. The newer models will deal
with repeating power failures much better than the unit you have now. If
this is just a nice feature or something essential all depends on the
quality of the grid you're connected to. For me, it is irrelevant, but for
you it could make all the difference.

Best regards, Arjen
-- 
Eindhoven - The Netherlands
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