[ale] OT: question about replacing batteries in a APC UPS

[Mike Harrison]

On Mon, 19 Dec 2005, Christopher Bergeron wrote:

> Before blasting APC, was your power source cleanly grounded; or did it 
> have an open loop?

Can you define 'open loop'? 

In Electronics Terms:

Open - a break in continuity where there should be some.

Loop - a closed/completed circuit, half of a transformer through a light 
       bulb is a continous loop, 

Perhaps you just meant an open or intermittent ground wire? 

As a Clinical Engineer and BioMedical Electronics Technician who used to
test for ground path resistance in medical equipment settings 
(where milli-ohm and micro-amps are important), I can
assure you that these rack mounted units were both properly grounded via
the cord (3 and 4 prong twist lock) as well as the metal well grounded via
overhead rack and seperate copper drain wire. The wiring was installed by
licensed electricians familiar with the environment, 1 was at our NOC, 1
was at WorldCom. Both were tested before and after with a NBS (National
Bureau of Standard) tracable Fluke Digital Volt Meter... by me.

The bigger APC's should alarm on plug in for faulty wiring as well. 

APC's were the only medium/larger UPS's that used friggin relays
as well.. nasty noisy cut-overs. Electrically noisy.

> I'd recommend testing your outlets with a cheap home depot tester before 
> installing a UPS.  A UPS will only be as reliable as the power source 
> beneath it.

Having spent 10's of thousands of my own money, and hundreds of thousands
of other peoples money on UPS's while building NOC's, I can assure you we
spent that money because a good UPS install is MUCH MORE reliable that the
power source that feeds it. That is why you do it.

The computer outlets in my house are 'backed up' by two Tripp-Lite 
1500va SmartOnline UPS's, and a Liquid Propane 7kw Generac Generator.. 
Works Great!

APC's just remind me of Microsoft: They make a big deal out of that 
warranty paperwork/insurance policy instead of how good their product is.