[Nut-upsuser] compaq r3000 triggering the fuse when power is reconnected

[Per Jessen]

Arjen de Korte wrote:

> Citeren Per Jessen <per at computer.org>:
> 
>> I have a fairly old Compaq R3000h which is overdue for new batteries.
>> Before I go and splash out a few hundred francs, I'd just need a
>> quick sanity check -
>> when I disconnect the power (UPS under load), it cuts out pretty much
>> right away, so the batteries are flat (even though the charge
>> indicator says full).
> 
> That's usually the tell tale sign that the batteries are well past
> their 'due to replace by' date. When was the last time you ran a deep
> discharge test on them?

Not sure - I'll have to admit my ignorance and ask what is that? 

>> When I reconnect the power, the surge triggers a 16A mains
>> fuse.  This sounds to me to be due to the batteries being completely
>> flat and thereby causing a major surge on startup?  Sounds
>> reasonable?
> 
> Depends on whether or not anything is attached at that time. If a
> number of computers is attached to the outlets, the combined inrush
> current may already be enough to trigger a circuit breaker. The same
> goes if it is not the only device connected on that group (maximum
> load of a 16A fuse is about 3.7 kVA).

I have two of these r3000, both with almost exactly the same load
attached - each is about 2.2kVA.  The other box does not trigger the
fuse when power is reconnected. 

> So while I agree that it looks like the batteries need replacement,
> this may not fix the above mentioned problem with the circuit breaker
> popping. Note that some UPS'es (and I believe the Compaq R3000h is one
> of them) allow for staged outlet switching. In that case it might make
> sense to not start all systems at the same time (if you're not already
> doing that).

Uh, interesting option - I didn't know the R3000 might have that.  I'll
have to take a look. 


thanks,
Per Jessen, Zürich