Author Topic: Is Anyone Familiar with this Surplus UPS ? (Read 1606 times)

Slingshot · « **on:** April 05, 2006, 07:58:40 PM »

Are these surplus phone-company units a good bet? Pretty easy to get going? Documentation available? Decent efficiency? I've been offered up to 3 of these for $75 apiece. Is that a reasonable deal? Thanks!

electronbaby · « **Reply #1 on:** April 05, 2006, 02:05:43 PM »

That looks more like a rectifier than a UPS. I could be wrong though. A rectifier (in the telco sense) is used to float all the equipment and batteries at -48vdc. If power were to go out to the rectifier, then the equipment wouldnt fail because it is connected in parallel with the batteries.

RoyR

KB2UHF

Nando · « **Reply #2 on:** April 05, 2006, 03:22:39 PM »

THIS IS A FANTASTIC 48 VOLTS battery charger -- do not take apart.

The specifications are extreme, like low noise, low ripple and very constant charging current, as well as, accurate voltage regulation, also long lasting.

May be a good search may give you the service manual.

It is positive grounded for negative 48 volts telephone systems but some can be terminal exchanged.

Nando

Slingshot · « **Reply #3 on:** April 05, 2006, 04:21:14 PM »

I'm sure it's more than a rectifier, as is has a very large transformer mounted within. Also, the 50-amp DC meter is labeled "discharge current".

Slingshot · « **Reply #4 on:** April 05, 2006, 04:25:09 PM »

Nando,

Are you certain it is a charger only, and nothing more? I'm curious because the DC ammeter is labeled "discharge current".

Opera House · « **Reply #5 on:** April 05, 2006, 04:42:06 PM »

Perhaps the operative words on the label are "AC IN" and DC OUT".

TomW · « **Reply #6 on:** April 05, 2006, 05:06:04 PM »

BINGO!

Shadow · « **Reply #7 on:** April 05, 2006, 05:13:20 PM »

This appears to be similiar to the ones I have. Mine are 240 or 120 volt AC in, 48 volt DC out. Mine has the settings for float, or equalize.I hooked one up 120 volt and have used it to charge my battery bank.

It would be good if you have access to grid power.

Nando · « **Reply #8 on:** April 05, 2006, 09:09:03 PM »

YES IT IS a charger

The discharge meter is important for the telecom service, the supply feeds the telephone lines and if the battery is supplying current THAT IS A NO-N0 to investigate.

This seems to be 1970's model that had that type of meters.

High quality and long life 100,000 hours life, they are now being changed because new regulations of PF GRID loading.

Nando

Slingshot · « **Reply #9 on:** April 06, 2006, 09:12:27 AM »

Thanks to all for your discussion and comments. As these devices are useful only for battery charging and/or as a 48-V power supply, I'll probably pass on the deal.

ghurd · « **Reply #10 on:** April 06, 2006, 09:17:36 AM »

I expect someone here will want them for that kind of money!

(not me)

G-

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