CVT vs Online UPS

[Fiftyfifty]

Hi

For the past 3 years, I have been using a 3kva Emerson double conversion online UPS. Lately, it has been malfunctioning and I'm afraid I will need to replace it. I'm looking for a product that will give me 3kva output, is durable, pure sine wave, constant voltage and power back up of at least 15 minutes. An online UPS satisfies all the above criteria, so maybe I can get one. Perhaps a different brand, e.g., APC.

At this stage, I wanted to know if a CVT is a better option. If yes, then what are the advantages a CVT provides as compared to a UPS? And can I get a 15 minute backup facility in the CVT? Someone told me that is possible by asking the vendor to provide additional capacitors.

I'll be grateful for inputs.

Thanks

 

[square_wave]

Can you shed some light on the malfunctioning part ? Modern UPS systems are quite modular and easily fixable.

 

[HTuser]

As per my understanding, you won't get any backup in CVT. For 3KVA kind of load capacitors won't be able to hold power to run them

CVTs typically make more noise than UPS - based on my past experience, their efficiency is considered to be less.

If you need proper voltage and battery backup, Online UPS is the better option

 

[Fiftyfifty]

Can you shed some light on the malfunctioning part ? Modern UPS systems are quite modular and easily fixable.

About 3 months ago, it beeped, squealed and shut down, refusing to power up. The dealer said the power supply and mother board needed to be replaced, which cost me 10k. Then a month ago, the ups would frequently slip into bypass mode, i.e., the current would bypass the ups and flow directly into my equipment, voltage fluctuation and all. This was despite the input voltage being within the range of the ups. Now they tell me that this is because my load is 70 percent (of 3kva) which is pretty high. My argument is that this was never an issue in the past, so the high load cannot be the reason for the malfunctioning. The dealer is working on the problem but i doubt they will be able to resolve it completely.

Thank you for responding.

Best

 

[panditji]

CVT makes a humming noise and therefore needs to be kept in a different room than the audio equipment.... Online UPS as you are aware is silent and provides pure sine wave power... CVT would need to be kept at the mains...

 

[devdutta]

About 3 months ago, it beeped, squealed and shut down, refusing to power up. The dealer said the power supply and mother board needed to be replaced, which cost me 10k. Then a month ago, the ups would frequently slip into bypass mode, i.e., the current would bypass the ups and flow directly into my equipment, voltage fluctuation and all. This was despite the input voltage being within the range of the ups. Now they tell me that this is because my load is 70 percent (of 3kva) which is pretty high. My argument is that this was never an issue in the past, so the high load cannot be the reason for the malfunctioning. The dealer is working on the problem but i doubt they will be able to resolve it completely.

Thank you for responding.

Best

I am using MIcrotek 3kva online ups for last 2 years for my setup including two amps, two subs. No problem at all. I got it for 22k using it with six nos 26ah battery externally. Instead of repairing if possible go for new one. My previous online ups 1kva it was having problems repeatedly after repairing it each time. So i dumped it.
Regarding CVT it will give u no back up at all. It will produce very irritating noise while maintaining the constant voltage.

 

[rbalagopalan]

I have been using Bhurji CVT with Isolation for the past six years. Absolutely no issues. In my experience Bhurji makes almost 50% less noise than other CVTs of the same rating. Cause Bhurji uses "I' core winding than regular 'E' core. Still it is suggested to keep them out of the auditioning room.

Bhurji CVTs are fully balanced. Since you get the isolation also together you get pure voltage.

CVTs dose make noise. As it gets heated up the core gets expanded and the noise reduces considerably. Also it is better to give sufficient load to CVTs while powered.

NIL Recurring expense and absolutely zero maintenance.

Power back "NO WAY" with CVTs. If your power back up requirement is primarily for Projector then my suggestion would be to keep a 800va ups seperately for projector.

 

[Fiftyfifty]

My power back up requirement is because there are frequent power failures here in Pune and i need an opportunity to switch off the equipment.
Even my UPS is kept in another room, therefore done noise is not an issue for me.
As i understand from all the responses, power back is out of the question with a CVT. Understood!
My other question is whether there is any difference in quality of power between a CVT and an online UPS?

 

[prem]

Fiftyfifty, give safety first preference. So do whatever needs to be done to make sure everything is safe.

 

[dr khanwelkar]

My other question is whether there is any difference in quality of power between a CVT and an online UPS?

CVT will give you Constant voltage and nothing else.
With online UPS you will get
1) Constant Voltage
2)Power back up.
3) Clean A.C Power with no element of DC
4) Clean Negative
5) Ground Isolation so no need of isolation transformer so no ground loop humming
It will not be silent.It will make noise as there are fans to cool down circuit and only heat sinks will not cool 2 KVA load.
Online UPS wins hands down

 

[square_wave]

About 3 months ago, it beeped, squealed and shut down, refusing to power up. The dealer said the power supply and mother board needed to be replaced, which cost me 10k. Then a month ago, the ups would frequently slip into bypass mode, i.e., the current would bypass the ups and flow directly into my equipment, voltage fluctuation and all. This was despite the input voltage being within the range of the ups. Now they tell me that this is because my load is 70 percent (of 3kva) which is pretty high. My argument is that this was never an issue in the past, so the high load cannot be the reason for the malfunctioning. The dealer is working on the problem but i doubt they will be able to resolve it completely.

Thank you for responding.

Best

This is a little weird. 3KVA is plenty of headroom. 3kva will give you atleast 2400 to 2600 watts at 80 to 90 % efficiency which is usually the case. The guy is telling you that you are using almost 2000 watts ! How is that even possible unless you are using some crazy gear which I do not see in your signature ?

I have seen 2kva ups systems powering big systems with ease.

What is the model number of this device ?

I have an APC double conversion 2kva. It never ever had an issue in the last 5 years or so. The battery now needs replacement, that is it!

 

[Nikhil]

I've been using APC Smart UPS series for several years.
My model is no longer available but here are the equivalent models

2KVA Model:

APC Smart-UPS RC 2000VA, 230V, rackmount w/kit, 4U, 8x IEC 60320 C13 outlets, harsh environment - SRC2000XLI-CC | APC India

SRC2000XLI-CC - APC Smart-UPS RC 2000VA, 230V, rackmount w/kit, 4U, 8x IEC 60320 C13 outlets, harsh environment | APC India

www.apc.com

3KVA Model:

APC Smart-UPS RC 3000VA, 230V, rackmount w/kit, 4U, 8x IEC 60320 C13 outlets, harsh environment - SRC3000XLI-CC | APC India

SRC3000XLI-CC - APC Smart-UPS RC 3000VA, 230V, rackmount w/kit, 4U, 8x IEC 60320 C13 outlets, harsh environment | APC India

www.apc.com

.

 

[rbalagopalan]

My other question is whether there is any difference in quality of power between a CVT and an online UPS?

CVT will give you Constant voltage and nothing else.
With online UPS you will get
1) Constant Voltage
2)Power back up.
3) Clean A.C Power with no element of DC
4) Clean Negative
5) Ground Isolation so no need of isolation transformer so no ground loop humming
It will not be silent.It will make noise as there are fans to cool down circuit and only heat sinks will not cool 2 KVA load.
Online UPS wins hands down

Yes i agree with general market CVTs are like what you have explained.

Bhurji CVT is fully balanced hence you will get clean Neutral. CVT with "I" core transformer.

It gives pure Sine wave output.

It dose have ultra high isolation also and that's the best part you can eliminate harmonics too.

A 2 KVA Bhurji weighs around 45 to 50 kgs not like 4kva AC stab which weighs around 6 kgs. Then you can imagine the amount of copper winding.

They are built like a tank and sudden drawing of power from the CVT is handled like a breeze given its transformer and Capacitors size.

But for power backup i feel a Bhurji CVT is a better option than an UPS or a Servo.

Thanks

Balagopalan

 

[dr khanwelkar]

similar is available with Insignia Thane.

 

[Fiftyfifty]

This is a little weird. 3KVA is plenty of headroom. 3kva will give you atleast 2400 to 2600 watts at 80 to 90 % efficiency which is usually the case. The guy is telling you that you are using almost 2000 watts ! How is that even possible unless you are using some crazy gear which I do not see in your signature ?

I have seen 2kva ups systems powering big systems with ease.

What is the model number of this device ?

I have an APC double conversion 2kva. It never ever had an issue in the last 5 years or so. The battery now needs replacement, that is it!

Because of the Power Factor on my Power Conditioner, it draws around 2300 watts

similar is available with Insignia Thane.

Similar to what?

 

[newlash09]

Hi

For the past 3 years, I have been using a 3kva Emerson double conversion online UPS. Lately, it has been malfunctioning and I'm afraid I will need to replace it. I'm looking for a product that will give me 3kva output, is durable, pure sine wave, constant voltage and power back up of at least 15 minutes. An online UPS satisfies all the above criteria, so maybe I can get one. Perhaps a different brand, e.g., APC.

At this stage, I wanted to know if a CVT is a better option. If yes, then what are the advantages a CVT provides as compared to a UPS? And can I get a 15 minute backup facility in the CVT? Someone told me that is possible by asking the vendor to provide additional capacitors.

I'll be grateful for inputs.

Thanks

Hi fifty fifty....

Both CVT and servo stabilizer do the same thing. Effectively maintain constant voltage at the out out.. I've tried both...a CVT is faster to react to voltage changes so it doesn't Rob off dynamics. But on the negative side it hums. Though inaudible once the music is on..So that is Some thing to bear in mind.

Servo stabs are slower to react, but are quiet. I have one in my system presently, and I can't hear it unlike the humming cvt before. So I guess you have to take balanced decision. But I would always prefer high power components like power amps direct to wall. Only small power boxes like dac's and preamp benefit from these power treatments in my limited experience

 

[square_wave]

Because of the Power Factor on my Power Conditioner, it draws around 2300 watts

Ah..Ok. What power conditioner is this ?

 

[Fiftyfifty]

Ah..Ok. What power conditioner is this ?

Furman Elite 16

Fiftyfifty, give safety first preference. So do whatever needs to be done to make sure everything is safe.

Yes, safety is important. Therefore, however good the unit may be, my equipment is at risk when the power gets cut off suddenly. Hence the need for back up

 

[dr khanwelkar]

Similar to what?

"I" core transformer.

 

[AVM]

I have been using 2 kva APC online ups for 6 years now. No issues other than battery being replaced once.