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leibold
MVM
join:2002-07-09
Sunnyvale, CA
Netgear CG3000DCR
ZyXEL P-663HN-51

leibold to TWC_User

MVM

to TWC_User

Re: Surge Protector vs UPS for my room?

No, I wouldn't go so far as saying that AVR is useless but the (often significant) extra cost for the feature may not be a good investment if you don't really need it.

Look at the devices you are protecting and see how concerned you need to be about the line voltage. Most electronic devices these days with switch mode power supplies are perfectly happy to accept AC in a wide range (e.g. 100V to 250V) and don't really care about the line frequency either.

A historic tube radio operating directly with rectified line voltage is a lot more sensitive to voltage variations then any modern electronics would be.

Another thing to keep in mind when deciding whether or not to get a double conversion UPS is the energy efficiency. In a double conversion UPS the AC/DC and DC/AC converters are both continually operating and neither is 100% efficient. This means energy losses and excess heat.
In a simple UPS relay contacts connect input and output and the AC/DC converter is only used while charging the battery while the DC/AC converter (inverter) isn't used at all (until there is a power loss). This means in terms of energy efficiency a simple UPS will always beat a double conversion UPS.

If you live in a place with a stable electric utility grid I would say that an AVR feature is really not necessary. If you live in a place where power is unreliable and fluctuates a lot then AVR (or double conversion) would certainly rise in priority.
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

1 recommendation

TheMG

Premium Member

said by leibold:

Most electronic devices these days with switch mode power supplies are perfectly happy to accept AC in a wide range (e.g. 100V to 250V) and don't really care about the line frequency either.

And that 100-250V rating is the nominal line voltage. There is an added tolerance on top of that. Realistically, most devices rated 100-250V should operate fine from about 90-270V or wider range.

For comparison the AVR feature in APC SmartUPS products, if my information is correct, only operates down to a minimum of 85V. So there's only a margin of about 5V where the AVR is actually useful as far as modern electronics are concerned.

Some double-conversion type UPS that I have tested (oh the fun one can have with a variac) will go down to 60V without using the batteries and maintain 120V at the output!