UPS Query.

Xccentricity · 09-10-2011, 01:40 PM

Config:-

FSP Saga II 500W SMPS
AMD Athlon 64 3000+ (2.0GHz)
MSI K8MM-V Motherboard, 2x80mm Fans
2x1 GB DDR1 400MHz RAM
Geforce 7300GT CPU (AGP)
Benq G2222HDL Monitor
LG CD/DVD Writer
Seagate 1TB HDD (7200.12, SATA)
PS/2 Keyboard and Mouse
DLink DWA-125 USB WiFi Adapter
Windows 7 Ultimate (32-bit)

No plans to add any future hardware except a Blu-Ray Writer, and another SATA HDD(2TB),

I need the UPS just to shutdown the PC as soon as the power goes, nothing else,

Would a APC 600VA UPS suffice? Or any other suggestions?

thetechfreak · 09-10-2011, 05:21 PM

Yes it will do. But you *might* need a new PSU if you add a Blu-Ray Drive

Xccentricity · 09-10-2011, 05:45 PM

Forgot to mention the PSU - FSP Saga II 500W PSU.

pimpom · 10-10-2011, 12:31 AM

Your system is not power-hungry even with the future additions. Power consumption will probably not exceed 200W peak, much less at idle or light usage. IIRC the 600VA APC is rated for ~360W. So you can put your mind at ease and use the APC 600VA UPS.

dashing.sujay · 10-10-2011, 02:03 AM

@pimpom- Its a bit off topic, but pls explain this 600VA=360W funda technically.

TIY

pimpom · 10-10-2011, 03:33 AM

First, it's not that 600VA equals 360W. It means that the UPS has different ratings for different conditions.

With DC, voltage and current always flow at the same time. In this case, voltage x current = power, or VA = P (in Watts).

With AC, the voltage is constantly changing in value and direction. If the load is resistive like an incandescent light bulb or a simple heater, then the current changes in sync with the voltage. In this case, VA = P as with DC.

However, with many types of AC load, e.g., motors, electronic products, etc., the current does not vary in sync with the voltage. The current is said to be out of phase with the voltage. In such cases, VA is not equal to P. In certain cases, we may have a considerable amount of voltage and current in the same circuit but zero power!

The ratio of power to volt-amperes is called the power factor. Thus P.F. = P/VA.

Power sources (generator, UPS, etc.) have maximum amounts of voltage, current and power that they can withstand. And since VA is not always equal to Power, we have to have separate ratings for VA and power.

I've tried to present a general picture so far. A more detailed explanation will involve some maths and diagrams. It's 3:30 AM now and i have to go to bed. Maybe we can continue later. You can also do some research yourself by reading about power factors.

jerrin_ss5 · 10-10-2011, 06:27 AM

Quote:

Originally Posted by pimpom

First, it's not that 600VA equals 360W. It means that the UPS has different ratings for different conditions.

With DC, voltage and current always flow at the same time. In this case, voltage x current = power, or VA = P (in Watts).

With AC, the voltage is constantly changing in value and direction. If the load is resistive like an incandescent light bulb or a simple heater, then the current changes in sync with the voltage. In this case, VA = P as with DC.

However, with many types of AC load, e.g., motors, electronic products, etc., the current does not vary in sync with the voltage. The current is said to be out of phase with the voltage. In such cases, VA is not equal to P. In certain cases, we may have a considerable amount of voltage and current in the same circuit but zero power!

The ratio of power to volt-amperes is called the power factor. Thus P.F. = P/VA.

Power sources (generator, UPS, etc.) have maximum amounts of voltage, current and power that they can withstand. And since VA is not always equal to Power, we have to have separate ratings for VA and power.

I've tried to present a general picture so far. A more detailed explanation will involve some maths and diagrams. It's 3:30 AM now and i have to go to bed. Maybe we can continue later. You can also do some research yourself by reading about power factors.

oh that's an interesting fact but i didn't understand how ups parameters are measured to watts?

Xccentricity · 10-10-2011, 08:50 AM

Thanks for your suggestions, how good is Numeric 600VA? Any other cheaper UPS which would be comfortable for my config?

dashing.sujay · 10-10-2011, 08:59 AM

Quote:

Originally Posted by pimpom

First, it's not that 600VA equals 360W. It means that the UPS has different ratings for different conditions.

With DC, voltage and current always flow at the same time. In this case, voltage x current = power, or VA = P (in Watts).

With AC, the voltage is constantly changing in value and direction. If the load is resistive (wtH resistive load is ) like an incandescent light bulb or a simple heater, then the current changes in sync with the voltage. In this case, VA = P as with DC.

However, with many types of AC load, e.g., motors, electronic products, etc., the current does not vary in sync with the voltage. The current is said to be out of phase with the voltage. In such cases, VA is not equal to P. In certain cases, we may have a considerable amount of voltage and current in the same circuit but zero power! how ?

The ratio of power to volt-amperes is called the power factor. Thus P.F. = P/VA.

Power sources (generator, UPS, etc.) have maximum amounts of voltage, current and power that they can withstand. And since VA is not always equal to Power, we have to have separate ratings for VA and power.

Once again thnx pimpom for your good electrical concept explanation

Queries-
1) I read online about PF, tell me what in AC circuits causes P =! VA ?
2) Explain the highlighted lines.
3) So, basically, Power is the most important thing one has to keep in mind while buying a UPS?
4) Why don't PSU's have also a separate VA and power rating ? (sry if i sound n00b)

TIY

Quote:

Originally Posted by Xccentricity

Thanks for your suggestions, how good is Numeric 600VA? Any other cheaper UPS which would be comfortable for my config?

Numeric is a good brand, but if you real want cheap UPS's, you can go for intex/microtek ones. I'm using a intex greenX 600, and its working fine for me.

Xccentricity · 15-01-2012, 12:01 AM

Sorry for bumping an old thread-------------

I need to buy another UPS for a similar config(everything is same except as the above config except its a P4 with 865P chipset, 7300GT AGP), but my budget is lower, how good is Zebronics, iBall, Matrix (600VA ones)?

And the other system has a Dell ST2220L monitor, would a 600VA UPS be enough to support both the the monitor and system?

Requirement is just 5-10mins to shutdown the PC.

casual_gamer · 15-01-2012, 02:12 PM

Quote:

Originally Posted by Xccentricity

Config:-

FSP Saga II 500W SMPS
AMD Athlon 64 3000+ (2.0GHz)
MSI K8MM-V Motherboard, 2x80mm Fans
2x1 GB DDR1 400MHz RAM
Geforce 7300GT CPU (AGP)
Benq G2222HDL Monitor
LG CD/DVD Writer
Seagate 1TB HDD (7200.12, SATA)
PS/2 Keyboard and Mouse
DLink DWA-125 USB WiFi Adapter
Windows 7 Ultimate (32-bit)

No plans to add any future hardware except a Blu-Ray Writer, and another SATA HDD(2TB),

I need the UPS just to shutdown the PC as soon as the power goes, nothing else,

Would a APC 600VA UPS suffice? Or any other suggestions?

Quote:

Originally Posted by pimpom

Your system is not power-hungry even with the future additions. Power consumption will probably not exceed 200W peak, much less at idle or light usage. IIRC the 600VA APC is rated for ~360W. So you can put your mind at ease and use the APC 600VA UPS.

if his power consumption will not exceed 200w even during peak period, will a 250w psu not be enough instead of his FSP 500w?