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

[Arjen de Korte]

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?

> 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).

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).

Best regards, Arjen
-- 
Please keep list traffic on the list