Wanted: Pinout for Minuteman Alliance A425 UPS proprietary serial cable . . .

[Stan Shankman]

Greetings all,



I have this UPS (Uninterruptible Power Supply) that needs a serial cable to
communicate with the computer.



For whatever reason, the manufacturer, Para Systems Inc., has chosen to make
this cable special.



So, I would like someone who has one of these units, to take the time to do
a continuity check on the cable and report back. I know I am not the only
person that would benefit from this. I have searched the web, and found
others needing this vary assistance, but none have found the solution.



I suspect that some of the pins are tied together, that some wires crossed,
and there may even be a capacitor or resistor or diode hidden in the
connector assembly, I really don’t know.



Anyway, if you have one, I would appreciated it if you would check it out
for us all. ;-)



Again, the unit in question is:



Para Systems Inc.

Minuteman Alliance A425

425-Watt Uninterruptible Power Supply



Also, is anyone using one successfully with windows XP? What settings does
it work with?



Thanks!

- Stan Shankman K7SJB

 

[Travis Jordan]

I have this UPS (Uninterruptible Power Supply) that needs a serial
cable to communicate with the computer.
Minuteman Alliance A425
425-Watt Uninterruptible Power Supply

Not really - it is a 425VA UPS (about 275 W). Here's the DB-9 pin outs.

http://www.minutemanups.com/support/manuals/alliance_manl_eng.pdf

This is a 10 year old UPS and no doubt the batteries are gone by now.
I'd scrap it and buy a 350VA APC UPS next time it is on sale at Staples
for $30.

 

[Stan Shankman]

Travis,
Hey thanks for the reply!
Yeah, I checked out the link you gave, and it defiantly states it is a
275-watt output unit.
But I don't get it. What is the 425-VA rating if not power in watts?

Oh, and thanks for the 'Staples' tip. I will defiantly stop in and check
that out!
By the way, you have also given the APC units rating in units of "VA".
So, does this mean that it will be less than 275-watts output?

- Stan Shankman

 

[Dave D]

Travis,
Hey thanks for the reply!
Yeah, I checked out the link you gave, and it defiantly states it is a
275-watt output unit.
But I don't get it. What is the 425-VA rating if not power in watts?

VA means volt-ampere.

http://www.pcguide.com/ref/power/ext/basicsPower-c.html

It's basically an AC power term which takes into account phase and inductive
loads. It's not my area of knowledge, so perhaps someone could elaborate.

Dave

 

[Travis Jordan]

By the way, you have also given the APC units rating in units of "VA".
So, does this mean that it will be less than 275-watts output?

Yes, the 350VA UPS is 200W. Of course they also make bigger sizes, for
more $$$. For most applications where you have a home PC and just need
'ride through' capability for those intermittent power glitches, the
350VA system is fine.

http://www.epinions.com/pr-APC_BE_3...pp_~1/sort_~wtb_price/sort_dir_~asc/sec_~wtb#
awtb

 

[Dave D]

It's basically an AC power term which takes into account phase and
inductive loads.

Sorry, I should probably have added 'reactive loads' as well.

Dave

 

[Stan Shankman]

I still don't understand.

Isn't one VA equal to one watt? A watt is a volt-amp.

How can a unit be both 425 VA and 275 Watt?

 

[Dave D]

I still don't understand.

Isn't one VA equal to one watt? A watt is a volt-amp.

How can a unit be both 425 VA and 275 Watt?

No, a VA is not equal to a watt. To understand this you need to understand
the differences between measurements of power for DC and AC. Try reading my
post and following the link.

Dave

 

[Stan Shankman]

Dave D,



Hey, I did finally read that power-factor FAQ sheet you so nicely pointed me
to, and yes, it did answer all of my questions.

So, thanks for that!



I also had the thought of just using a car (or deep cycle) battery with my
unit but upon further reading, discovered that I might have problems that
way with completely dead battery charging. This is so, presumably, because a
dead battery presents a larger load to the existing charger. So I'm
wondering if anyone can speak about that issue.



I have been checking around on eBay and Craigslist for used UPS units, and
it seems reasonable to expect I might find a good used rig that way.



Also, for your information, I have found a few web sites that do sell
replacement batteries at what appears to be very good prices. - Half (or
better) of what one would expect to pay locally! So if anyone needs a
battery, you should check around on the web. I know I was pleasantly
surprised to find these reasonable prices. (Prices very widely, so keep
checking for the least costly ones.) I have also noticed that enterprising
individuals are buying lots of old UPS units and then replacing the
batteries with these new cheap replacements and then selling the refurbished
units on eBay - again, at what seems like very reasonable prices. - That may
not be a bad way to go.



Thanks for the help,



- Stan Shankman K7SJB

\

 

[Dave D]

Dave D,



Hey, I did finally read that power-factor FAQ sheet you so nicely pointed
me
to, and yes, it did answer all of my questions.

So, thanks for that!

Glad it helped

I also had the thought of just using a car (or deep cycle) battery with my
unit but upon further reading, discovered that I might have problems that
way with completely dead battery charging. This is so, presumably, because
a
dead battery presents a larger load to the existing charger. So I'm
wondering if anyone can speak about that issue.

I was going to try that myself a few years ago- I wanted to replace the
existing batteries with car batteries. I think I reached the same conclusion
as you did.

Dave

 

[David Lesher]

I also had the thought of just using a car (or deep cycle) battery with my
unit but upon further reading, discovered that I might have problems that
way with completely dead battery charging. This is so, presumably, because a
dead battery presents a larger load to the existing charger. So I'm
wondering if anyone can speak about that issue.

Yea; don't worry about it. I put 50AH batteries on my 900VA SmartUPS that
had ?6-8? AH originally. Yes, it charges slowly. It may take a few days.

But the charger puts out what it can, and the resistance of a discharged
6AH string is not much different than a discharged 50AH string.

And it was nice having a UPS that lasted ~24 hours under light loads...

But forget the car batteries; use deep-cycle ones.