APC Smart-UPS SC 420VA to provide studio power during outage.. or no?

It will not be easy since the switching circuits (DC-AC inverter) inside the unit is designed to produce the higher AC voltage. This would require changing out the switching transformer and most likely several other components that make up the switching circuit on the transformer primary side. The secondary side will have components that will also have to be changed over as well as sensing circuits (feedback loops).

However you now have a hefty DC-AC inverter and with the use of a step down transformer on the output, you can use the unit for 120vac. The only thing that may hamper any use of it is the unit's AC cycle. If its putting out 60 hz..your fine. If its putting out 50 hz...that presents a problem for most devices. Powering lights wont be a problem though (standard filament bulbs) but trying to power electronics that mostly use switching power supplies may not work unless the device can handle a 50 cycle or 60 cycle source.

For the input side (plugging into the wall to charge up), you can use a step-up transformer or set up a 220v outlet specifically for it. Again the issue of 50 cycle and 60 cycle difference might present a problem if the unit can only handle 50 cycle current.

There should be somewhere in the specifications what duty cycle it can handle. If anywhere in there it says 220/240vac 50/60hz...your ok and will not have to worry about any step up transformer. But for the output, you will need a step down transformer to bring its output from the 220/240 down to the 120 level.

RFB

Thanks for the input RFB (pun!),
I'm quite confused, While it is still a APC Smart-UPS SC 420VA UPS, I have found these particular models are imported units referred to as model SC420I, and upon looking around, this exact same model is readily available online at Walmart, Sears, Office Depot, and a lot of other outlets..
Why would this be readily available in the states?

I can not find any info on how one would actually utilize one of these here, but it does specify: Input Frequency 50/60 Hz +/- 3 Hz (auto sensing).
While I am finding step-down and step-up transformers for under $10, I really don't know what I would be doing and wouldn't want to risk destroying my equipment.. If it were as easy as simply "plugging it in" is one thing, but changing out several inner components as you describe is another (I am a complete novice).
I think in my situation, my best bet may just be to take my losses..
Do you agree?
This is the actual unit I have: http://www.apc.com/resource/include/techspec_index.cfm?base_sku=sc420i

Just in case ...
http://www.sportsimportsltd.com/1622acto11ac.html

But if you call a local electrician, there may be a converter right in the shop.

Here in the U.S. most homes are wired for 120vac and 240vac. I think these voltage numbers are "nominal" and are not always stated the same way. We often see 110v or 119v and 220v, I think always intending to say the same thing. In fact true voltage readings will vary.

One idea is that you probably have 240vac somewhere in the house, for the washing machine, an air-conditioner, an electric stove, and you can always have a new branch put in. Then maybe your power unit could be used.

Another idea, some equipment contains internal adjustments for either 110vac or 220vac. I had a tape recorder that was like that and I've seen computer power supplies with that feature.

Keep checking it out.

If the unit manual gives the wide spread of input voltages you have mentioned, then there is the possibility you will only have to move the input transformer voltage tap from 230 to 120 volts. If you can get them to give you the change instructions and you don't feel comfortable doing it yourself, take it to a motor winding shop and have the technician do it for you.

APC-Schneider has great customer support people and they are here in the U.S.

http://www.apc.com/support/

Marshall, I sent them an inquiry briefly detailing the situation thru their tech help form a few minutes ago.. But I also am fortunate to find out that one of my roomates (There are about 5 of us that share this house which belongs to our local florist). Anyway, one of my roomates is a ex navy man who had a stroke a few years ago, and he says "I can make that work!, I need a new project to excercise my brain!"
I hope he can.
If so, lucky luck me!

Maybe, if the output has a ground connection you could use this as a neutral return from the load. This would give 120 VAC from each side of the 220 volt output to the ground connection.

There may be a load balance and safety issue but you could ask the manufacturer if this is possible. Don't try this without an OK from APC.

If it is OK then you could make an adapter cable.

Neil

Recently you requested personal assistance from the APC Customer Care Center through our on-line support center. Below is a summary of your request and our response.

We will assume your issue has been resolved if we do not hear from you within 14 days.

Thank you for allowing us to be of service to you.

Subject
APC Smart-UPS SC 420VA - 230va version

Discussion Thread
Response (Guru) 02/17/2011 09:30 AM
Dear Richard,

Thank you for contacting APC's email support on 02/16/2011 11:16 PM. I would be happy to assist you.

Richard, we do not recommend using international model UPS locally. International model testing is based on the primary environments in which it will be used. For example, units used in Europe must be verified according to EC Directives. All Smart-UPS international models can be sold in Europe because it is compliant with EN standards. UL (Underwriters Laboratory) has specific ratings and certifications for 120V models which are never performed on international models. That is, 230V Smart-UPS units would not be tested based on certifications appropriate for North America because the units are intended for overseas usage.

The grounding of an international unit differs from a 120V model. In the international model, there is normal mode surge suppression, but no common mode surge suppression. That is, there are no protective devices between the Neutral to Ground (N-G or the Hot to Ground(H-G) paths; therefore, no Site Wiring Fault Light is present. There is, however, full surge suppression between Hot and Ground (H-G). International models do not depend on the ground wire for surge suppression.

I request you to replace the UPS with a domestic equivalent rather than using a transformer.

If you have any further questions, please do not hesitate to contact me by responding to this incident. It would be my pleasure to ensure that your issue is quickly resolved!

Solutions to most common customer problems can be found in our APC Knowledge Base which can be found at:
http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_alp.php?ISOCountryCode=us

Thank you for choosing APC!
Customer By Web Form (Richard Powers) 02/16/2011 11:16 PM
Hello,
I've been given a new APC Smart-UPS SC 420VA which is about a year old, it has never been used since it was bought by mistake. It is a 230 va model (the international version).
My question is are there any settings or alternations I can make inside to enable me to use it in a 110/120v situation? Or perhaps by utilizing step-up and/or step down transformers?
In other words, is there anything I can do to use this as a 110 output?

The battery while presently low does still show a charge.

Thank you for any advice.

Best regards,

Rich

Question Reference #110217-000798
Product Level 1: APC Back-UPS
Category Level 1: Technical Assistance
Date Created: 02/16/2011 11:16 PM
Last Updated: 02/17/2011 09:30 AM
Status: Waiting
Model Number: APC Smart-UPS SC420I
Serial: QS0544222166
Management Software: PowerChute Business Edition
Version: Basic
Operating System: Windows XP

The above response is from the APC support team.. I am assuming it is, at least in part, an automated response - or at least a pre-selected response to such a question as the one I asked.

Now while I comprehend the response to basically say "We don't advise you use it", I am also assuming this is a required response by their company to protect themselves from a potential "backfire" of advising a person to use their product in a means not originally intended.

But in reference to their above response; Would those of you here who are experienced and technically minded say that it is still feasible to alter this unit for a 110 output?

---
Timmy, (one of the people living in this same house I live in) who I mentioned previously, claims he specialized in this kind of stuff when he was in the Navy... is not now, I speculate, as sharp minded as he once perhaps was before his stroke - however, I tend to believe that under his current handicap state, he still retains a degree of ability and expertise from his past.
But I can't know this for sure, nevertheless I'm willing to believe he still has such capabilities, and figure that I don't have much to loose in allowing him to attempt to make required alternations to this UPS unit.

All that said, and based on the APC response to my email.. What do you guys think?

I just realized I'm going round and round in circles in this post - So I conclude it now -- I think I got my point/question out!

I say let the ex-Navy have his fun. Worst case scenario he breaks it and you have a to buy a new one. (which you would do anyway)

My sentiments exactly Crow! - Personally I hope he does make it work, not just for my sake; but for his own.
Still, was also wondering if anyone would decipher the APC reply, or had any comments about it.

According to the email from APC, you will need to add surge suppression for neutral to ground and hot to ground for the unit to work properly after changing the INPUT voltage from 240 to 120. Also, there will be no fault warning even with these additions due to the difference in circuitry. Without the surge protection all of your AC to DC analog and switching power supplies can be at risk for over voltage and lightning damage.

I would plan on replacing the UPS eventually with a US model.

Wow, guess what happened this morning.. I had gone down front and got on the roof again to take a second look at something and in the process broke my reading glasses, so I stopped by our local thrift shop on the way back hope to buy a couple $1.00 pairs of glasses.. and there was a Dynex 800avr UPS unit sitting on a lower shelf.. I pressed the power button (it wasn't plugged in) and the little red light came on and made a single beep.. I picked it up to take a closer look and saw on the back it had a "wire fault" indicator light lit up - I don't know what that meant, but asked the lady how much, she asked me what it was, and I said it's some kind of power outlet extension.. she said $5

I carried it home, plugged a lamp into it - still hadn't plugged it in the wall yet and the lamp came on.. and stayed on for maybe an hour or so now with no sign of dimming - I just now went ahead and plugged the UPS in.. not because it went dead, but to go ahead and get a full charge on it. - I just noticed the red "wire fault" light is not on anymore, I'm not sure when it went off.
Although I haven't put any real load on this thing yet, it seems to be in good working order.

All this due to a broken pair of cheap reading glasses.

So now I own a UPS I paid about $40 for that I may or may not ever get to make use of, and a $5 UPS that seems to work perfect!
I'll look up the details of this fortunate find later.

I just had to tell you the story! This made my day!

Thats fantastic! See how things tend to work themselves out! 😀

RFB