Need help: Step Down/UPS connection

[sriji1212]

Thanks in advance for taking time to read this.

I have a Maxine 1000W step down to power my 110V AVR (400W) and Blu-ray player (<100W).

I had bought APC Smart UPS 1500 (pure sine wave) thinking I can connect the Maxine to UPS instead of direct power to get uninterrupted power to my audio/video. Sadly, if I connect Maxine to output of UPS, there is line power coming out in all 3 cores (G, N and L) and audible humming noise in Maxine. Got to discover the power issue because of mild electric shocks while touching AVR speaker terminals.

Thinking its a problem with Maxine, exchanged the Maxine with a new piece, but situation remains. Interestingly, the power output is very fine if I connect Maxine directly to the AC outlet. And there is no humming noise as well if connected directly to AC. So definitely the problem is with the UPS/Maxine connection.

1. Is this a common problem? Or is there a problem with UPS/step down?
2. Is anyone using step down/UPS connection? If yes, can you mention brands you are using?
2. Any recommended solution to connect step down to get uninterrupted power?

Power situation in my apartment/area is so bad that there is very frequent power cuts. Kind of 2 to 3 cuts in a 2 hr interval. My apartment has a Generator back up, so within 2-3 mins of power failure generator kicks in. So I have a need to connect to UPS instead of direct power and looking for solutions.

Thanks,
Sri

 

[blackscorpio]

I am in the same situation as yours, we also have frequent short power cuts and I am looking for a safe shutdown. Our HT and Stereo all are connected to a Maxine 3KVA step down, I was considering an online UPS, now this throws me off.

Thanks Sri for posting this. Really, I can't thank enough.

 

[baijuxavior]

This type of connection should be avoided. My Emerson UPS manual clearly states that you should not connect stabilizer to the ups output, but you can connect ups to stabilizer out. This is not useful in your cases as you won't get 110V from UPS.

 

[sriji1212]

This type of connection should be avoided. My Emerson UPS manual clearly states that you should not connect stabilizer to the ups output, but you can connect ups to stabilizer out. This is not useful in your cases as you won't get 110V from UPS.

Agreed, after mentioning this problem to the Maxine dealer, he showed me a fine print in the Maxine warranty card which mentioned "Warranty is void if connected to any type of stabilizer or voltage regulator". APC Smart UPS does have Automatic Voltage Regulation feature :-(

By any chance do you know any other options?

 

[sriji1212]

On searching further on line, looks there is APC step down transformer which goes along with APC Smart UPS (typically used in server racks). http://www.apcmedia.com/salestools/ASTE-6Z8LLZ/ASTE-6Z8LLZ_R0_EN.pdf
But the cost of it is around US $500+ which is very expensive to consider for my simple HT setup.

 

[hydrovac]

Sadly, if I connect Maxine to output of UPS, there is line power coming out in all 3 cores (G, N and L) and audible humming noise in Maxine. Got to discover the power issue because of mild electric shocks while touching AVR speaker terminals.
Thanks,
Sri

Hi Sri,

Did you change any stock plugs or sockets of the equipment?

Rgrds

 

[sriji1212]

Hi Sri,

Did you change any stock plugs or sockets of the equipment?

Rgrds

Nope, did not change any stock plug or sockets.

 

[hydrovac]

Nope, did not change any stock plug or sockets.

Are you using 3-prong tops all through, right from the wall out let. An outlet should always be checked to see if it is properly grounded.

How about your equipment power cables. Whether flat two pin or otherwise.

 

[sriji1212]

Are you using 3-prong tops all through, right from the wall out let. An outlet should always be checked to see if it is properly grounded.

How about your equipment power cables. Whether flat two pin or otherwise.

Thanks for probing questions. Let me know if any of the below shows any weak link.

AC Outlet is properly grounded. This is the first thing I checked with local electrician for cause for electric shocks in the AVR when Step down was connected to UPS. As I said earlier, there is no electric shocks when the step down is directly connected to AC outlet.

- UPS is connected to AC through 3 core cable (the normal computer power cable with IEC C14 on one side and 3 pin Indian style plug on the other)
- Maxine step down has 3 pin plug which *was* connected to UPS output (again a 3 pin outlet) (when there is a problem). Now, I have connected Maxine directly to power outlet.
- Belkin surge protector is connected to Maxine 110V output (both 3 pin)
- AVR has 2 pin plug which is connected to Belkin
- BD Player has 2 pin plug which is connected to Belkin

Thanks again!

 

[hydrovac]

Thanks for probing questions. Let me know if any of the below shows any weak link.

AC Outlet is properly grounded. This is the first thing I checked with local electrician for cause for electric shocks in the AVR when Step down was connected to UPS. As I said earlier, there is no electric shocks when the step down is directly connected to AC outlet.

- UPS is connected to AC through 3 core cable (the normal computer power cable with IEC C14 on one side and 3 pin Indian style plug on the other)
- Maxine step down has 3 pin plug which *was* connected to UPS output (again a 3 pin outlet) (when there is a problem). Now, I have connected Maxine directly to power outlet.
- Belkin surge protector is connected to Maxine 110V output (both 3 pin)
- AVR has 2 pin plug which is connected to Belkin
- BD Player has 2 pin plug which is connected to Belkin

Thanks again!

Man, you seem to be getting little impatient there. So, you want a solution without being asked any (probing)questions. The questions being asked are directly proportional to your query. You should have posted all the trouble shooting already done, if you wanted to avoid the embarrassment.

You think I am asking these questions for fun or to intimidate you? We are trying to bail you out of a buying decision you made on your own. The whole essence of this forum is to have a healthy conversation between members and help out each other.

Cheers

 

[sriji1212]

Man, you seem to be getting little impatient there. So, you want a solution without being asked any (probing)questions. The questions being asked are directly proportional to your query. You should have posted all the trouble shooting already done, if you wanted to avoid the embarrassment.

You think I am asking these questions for fun or to intimidate you? We are trying to bail you out of a buying decision you made on your own. The whole essence of this forum is to have a healthy conversation between members and help out each other.

Cheers

Hydrovac,
Seriously, I said *real* thanks for the probing questions as I also thought it will help me find the cause. Sorry if it sounded as sarcastic which I did not intend at all.

 

[blackscorpio]

I have had a local manufacturer of Sine Wave Inverter demo his unit at my home. The setup is connected as:
wall outlet > Sine Wave Inverter (2KVA) > Maxine Step Down (3KVA) > Anchor strip > all units (55 inch plasma, Denon 3312, STB).

Scenarios tested:
cold start
mains on
mains off

To my knowledge I didn't see any problems with the setup, it worked in all scenarios, no restart occured on switch over. Everything worked fine. Inverter output was pure sine wave and the guy told me that switch over delay was less than 10 milliseconds(3 milliseconds or so).

I was almost convinced to buy the unit but reading thru here, I wasn't sure if I should buy only an "ONLINE UPS".

What's the solution, if we cannot connect a step down to a UPS.

Confused.


Sri, hope I am not hijacking your thread.

 

[sriji1212]

Sri, hope I am not hijacking your thread.

Definitely not sir. It would eventually help me as well.

Scorpio, which inverter brand you had demoed? I hope that does not have voltage regulation/stabilization. I shall also check for a demo and if it works, shall sell the UPS and switch to inverter.

I am guessing if the Automatic Voltage Regulator (AVR) feature in APC Smart UPS is the culprit - need to demo other on line UPS brands which does not have this AVR feature. Hope to do this week end. Will keep you updated.

 

[blackscorpio]

I believe its unbranded and marketed under Achuth Electricals.

If APC's AVR is the culprit, does that mean we can use other brand online UPS. Or is there a technical limitation on using a step down with an UPS?

Guys, please help us here.
What are the options for power back up in case we have to use a step down? Can we use, Inverters or other types of UPS?

Can we use the Sine Wave inverter I demoed(explained in my earlier post)?

 

[blackscorpio]

appreciate any help here, any one?