Is line voltage of 250V safe for use with computers?

My SUA1000uxi smart ups(applies to other line interactive apc smart ups) lowest setting it would trim is 253v. It does have output setting of 220v,230v,240v but this setting is only applicable when it runs on battery. It will switch to battery if the input voltage exceeds more then 275v in other words it will trim the voltage to about 250v or less when the input is 275v but can give the set desired voltage only in battery.

Any line interactive ups or voltage stabilizer which has a multi tap transformer inside would buck or boost the voltage similary, the delta between the input and output voltage depends on the tap.

The only way to get a constant voltage is either get a online ups or attach a servo stabilizer to your house mains and get rid of all other stabilizers.
Or if your are sick and tired of the crappy power supply that you get from the power company because they dont rectify the problem switch to off grid solar like I intended to.(covid put brakes on mine)
 
@hadyp

Since you are considering an Online UPS here's what I found in my research prior to buying one.

You can find cheaper options with brands like Microtek, Champion etc. but I am very wary of their product quality not to mention their after sales service/support. If you are okay with these brands you CAN find cheaper options than APC.

I considered 3 APC options -

1.SRC1KI-IN - Cheapest (relatively speaking) of the three. Has Internal Batteries. No option to increase Backup time via External Batteries. Priced around 23-24k.

2.SRC1KUXI - More expensive than SRC1KI-IN when you factor in the cost of External Batteries. Uses External Batteries thereby offering longer backup times over SRC1KI-IN (provided you buy higher capacity Batteries). This model is priced around 19-20k (without batteries) .
Note:- APC dealers also force you to buy a "Battery Stand" for Rs.800 which IMO doesn't cost more than Rs.100 at max. This stand looks locally made and has no APC branding whatsoever.

3.SRC1KXLI - Most expensive of the three. Server Rack-mount Option. Has Internal Batteries and can apparently be further extended using External Batteries as well. Priced around 25k.

There are some differences between the 3.

The Spec sheets of SRC1KI-IN & SRC1KUXI are actually a combined sheet - a testament to the fact they are virtually identical in terms of looks & features with the main difference being that the Internal Batteries have been ripped out in SRC1KUXI and are supported externally. SRC1KUXI is also stated to have a "High-Power Charger", support for SMF & Flooded Batteries as well as User Selectable Charging Current (possibly required to cater to different types/capacities of External Batteries).

At first, I had decided on SRC1KXLI as it has some features/options not present in the other two - ie. 5 programmable output voltage Versus 3 for the other 2 models and a few other minor differences.

In the end I realized I don't really need those additional features and went with SRC1KUXI because I wanted the Extended Backup time it supported.

SRC1KUXI turns out about 2k more expensive than SRC1KI-IN when you factor in the cost of External Batteries and the (laughable) battery stand.

A note regarding the difference in backup times between SRC1KI-IN & SRC1KUXI-

For SRC1KI-IN, APC states its about 16 minutes at a load of 500W and approx 8 minutes on full load (800W). If your load is different you can refer to a model specific Run-time Graph with various loads on the APC site.

For SRC1KUXI - its very difficult to say what the backup time would be because this would depend on the type and capacity of the external batteries used.

However I was told by the APC dealer that its approx 35-40 minutes on full load (800W) with the batteries I purchased (Exide 2x12v 26AH batteries).

One last point - one of the reasons I like using APC is their Power Chute software. I was disappointed to see that APC bundles only a Serial cable in India with these UPS's even though there is a USB Port. As part of my research prior to buying the UPS I had downloaded and studied the Product Manuals for all 3 UPS's. The online product manual for SRC1KUXI CLEARLY STATES that a USB cable is included.

However when the UPS was delivered, the Paper Manual inside the box only mentions a Serial cable!

My guess is that the Online Manual is for the US/EU version whereas Indian users (as usual) get stiffed over this kind of thing.

Hope that helps...
 
Last edited:
Rickyk said:
@hadyp

Since you are considering an Online UPS here's what I found in my research prior to buying one.

You can find cheaper options with brands like Microtek, Champion etc. but I am very wary of their product quality not to mention their after sales service/support. If you are okay with these brands you CAN find cheaper options than APC.

I considered 3 APC options -

1.SRC1KI-IN - Cheapest (relatively speaking) of the three. Has Internal Batteries. No option to increase Backup time via External Batteries. Priced around 23-24k.

2.SRC1KUXI - More expensive than SRC1KI-IN when you factor in the cost of External Batteries. Uses External Batteries thereby offering longer backup times over SRC1KI-IN (provided you buy higher capacity Batteries). This model is priced around 19-20k (without batteries) .
Note:- APC dealers also force you to buy a "Battery Stand" for Rs.800 which IMO doesn't cost more than Rs.100 at max. This stand looks locally made and has no APC branding whatsoever.

3.SRC1KXLI - Most expensive of the three. Server Rack-mount Option. Has Internal Batteries and can apparently be further extended using External Batteries as well. Priced around 25k.

There are some differences between the 3.

The Spec sheets of SRC1KI-IN & SRC1KUXI are actually a combined sheet - a testament to the fact they are virtually identical in terms of looks & features with the main difference being that the Internal Batteries have been ripped out in SRC1KUXI and are supported externally. SRC1KUXI is also stated to have a "High-Power Charger", support for SMF & Flooded Batteries as well as User Selectable Charging Current (possibly required to cater to different types/capacities of External Batteries).

At first, I had decided on SRC1KXLI as it has some features/options not present in the other two - ie. 5 programmable output voltage Versus 3 for the other 2 models and a few other minor differences.

In the end I realized I don't really need those additional features and went with SRC1KUXI because I wanted the Extended Backup time it supported.

SRC1KUXI turns out about 2k more expensive than SRC1KI-IN when you factor in the cost of External Batteries and the (laughable) battery stand.

A note regarding the difference in backup times between SRC1KI-IN & SRC1KUXI-

For SRC1KI-IN, APC states its about 16 minutes at a load of 500W and approx 8 minutes on full load (800W). If your load is different you can refer to a model specific Run-time Graph with various loads on the APC site.

For SRC1KUXI - its very difficult to say what the backup time would be because this would depend on the type and capacity of the external batteries used.

However I was told by the APC dealer that its approx 35-40 minutes on full load (800W) with the batteries I purchased (Exide 2x12v 26AH batteries).

One last point - one of the reasons I like using APC is their Power Chute software. I was disappointed to see that APC bundles only a Serial cable in India with these UPS's even though there is a USB Port. As part of my research prior to buying the UPS I had downloaded and studied the Product Manuals for all 3 UPS's. The online product manual for SRC1KUXI CLEARLY STATES that a USB cable is included.

However when the UPS was delivered, the Paper Manual inside the box only mentions a Serial cable!

My guess is that the Online Manual is for the US/EU version whereas Indian users (as usual) get stiffed over this kind of thing.

Hope that helps...
Click to expand...
Thank you for sharing these details!
 
@ksp2000,
Don't worry too much about the line voltage. Most good PSUs have capacitor configurations rated for 500VDC (250 VAC will peak at 354 VDC, so about 30% headroom).

What you should worry about are voltage surges in the line. Most minor surges (from fans turning on/off etc) will be neutralized by the MOVs inside but the larger ones can kill the device.

Also, good PSUs have better load regulations and they seem to keep all the different output voltages within the ATX spec tolerances.

So, TL;DR, avoid poor quality PSUs and use a surge protection device.
 
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