Voltage Regulation - Line-R 1200VA (LE1200I) vs. APC BACK-UPS 700VA (BX700U-GR)

[mihai_apc]

Hi,

Can someone please help me compare the AVR in the following two products? Here's what I have found in the online documentation:

• Line-R 1200VA (LE1200I)
  
  • Output Regulation: ±10%
  • Response Time: < 2 AC Cycles
• APC BACK-UPS 700VA (BX700U-GR)
  • '“Double Boost and Single Trim” AVR instantly corrects voltage fluctuations without using the battery, allowing you to work indefinitely through sustained voltage increases and decreases.'

It probably comes down to what "Double Boost and Single Trim" actually entails.

Thanks in advance,

Mihai

[mihai_apc]

So no one knows what “Double Boost and Single Trim” means exactly?

Edit:

• User jordan wrote here: "Generally AVR has a +/- 12% range in the Smart UPS, unless your unit features double boost."
• User  Angela wrote here: "i cant find any white papers or anything but essentually, the UPS boosts or trims the voltage accordingly for undervoltages or overvoltages by percentage. i believe the percentage is 12% and some have a double boost of 24%. it takes this percentage from the input voltage."
  • She also references this KB link, but the page is no longer available.

If this truly means +24%/-12%, then the AVR in the BX700U-GR should be better than the one in LE1200I, at least in this regard (e.g. not considering the VA).

[BillP · Accepted solution]

Hi Mihai,

The percentage of boost or trim is really dependant upon the unit and how it was designed. Between 10-12% is a good estimate, however it may range for different functions. i.e 8% Trim, 10% Boost, 8% Double Boost. In this case I believe the actual percentages of each function are not as important as the voltage range of operation.  The BX700U-GR has a much wider range of operation (140vac - 300Vac) vs the LE1200I which is (160vac - 290vac). When the utility power increases above or decreases below these specified ranges, the devices will take appropriate action. The BX700U-GR will switch to it's inverter and provide you adequate power to allow you time to turn off your attached devices properly. The LE1200I on the other hand, will essentially turn off power to your equipment without warning, as there is no internal battery.

Deciding which is best for you is truly dependant upon what your needs and the needs of your attached equipment are.

Secret Squirrel

[mihai_apc]

Thanks  Secret .

What I'm looking for is the best AVR *range* I can get, w/out caring too much for a battery inverter since I'm using a laptop with enough life left in its internal battery.

The Schuko are a must for me, so I'd have to use an adapter if going for the LE1200I (too bad the LE1200-RS is not available in my area), while BX700U-GR has these sockets already and feels like a better option.

[voidstar_apc]

How much input voltage range do you need in your area? I'm curious because in my part of the world the voltage is stable until a power outage.

One other consideration: the lead acid batteries in a UPS last 3-5 years before requiring replacement, and the UPS will beep to let you know. I don't see mention of replaceable batteries on the BX700U-GR product page. The Line-R doesn't require battery maintenance.

[mihai_apc]

voidstar , it's actually very stable in the majority of the locations, but the truth is I haven't made a note of how far it temporarily goes away from the norm in the problematic ones. I think the actual problem comes from the lack of proper isolation between consumers in some small areas. Again, this is the exception, not the rule.

This is probably the perfect use case for the need to have an AVR in place, as opposed to frequently switching to battery. That's basically the main reason I'm looking for the best AVR in the price range, since that's the "feature" I'll be using the most.

[SamirD_apc]

Most laptops use a multi-voltage switching power supply so voltage variances don't really affect them since they're converting the AC to a fixed voltage of DC current.  I actually wouldn't worry about the power at all.  That's one thing laptops are really good at--running on dirty power.  They also have their own 'internal UPS', ie their battery. 😄

[mihai_apc]

Well put, Samir. Though I wonder what the output regulation percentage is for a good laptop adapter nowadays, because I vividly recall seeing laptop screens flicker on dirty power a very long time ago.

PS: I ended up getting the Line-R on a good discount. However, the discussion here is still very informative.

[SamirD_apc]

I can see how a cheap knock-off laptop power supply might do that.  That's why I will insist on only genuine branded ones (and not fakes, but the real deal) for our laptops.  Luckily, I find that I can get them at goodwill at $1-2 each on good days and they clean up well.  Something to keep in mind if you need a spare. 😉

[mihai_apc]

I never ever use cheapo / non-genuine stuff, so that's not the issue. Good tips though.

However, the question remains on how capable is the "AVR" inside a laptop power adapter, and that I'm sure greatly varies with the model. Maybe someone has performed some tests, as I've seen done for the Line-R, e.g. here: https://www.youtube.com/watch?v=lZ0VZ8_pP2k

[voidstar_apc]

Laptop power adapters today are switched-mode power supplies. As long as their input voltage is within the operating range, the output shouldn't be affected. A cheap chinese unit might have inadequate internal filtering allowing noise to bleed through, but OEM stuff should be solid.

Most AVR behave differently -- they output an AC voltage that depends on the input AC voltage (that's what the tests are showing). To do this, they have an internal transformer that can boost or trim the voltage by a fixed percentage. They have an output voltage range and activate boost or trim as necessary to keep the output voltage within that window.

Expensive double-conversion UPSes act more like a laptop power adapter and generate a fixed AC voltage, but they're more expensive and generally less efficient. Some of APC's newer UPSes have an AVR that does double-conversion although it's not labeled as such.

[SamirD_apc]

Very informative.  Thank you for sharing.

You mention that some model UPSs are doing double conversion--are these mainly the pure sine wave models?

[mihai_apc]

Valid point on switched-mode power adapters, voidstar. They should definitely do the typical AVR "boost" when targeting 230V. Not sure how much to expect for a "trim" function though.

[voidstar_apc]

Samir, I'm referring to some of the more expensive higher-VA SmartUPS' (yes, sine-wave).

Mihai, laptop power adapters and PC internal power supplies trim the voltage because the input voltage (230V AC) is greater than what they produce (various DC voltages, typically 30V or less). For example if you look at APC's offerings in laptop chargers, they offer 12V and 19V adapters. And if you look at the specs for one, they can operate from 100-240V AC generating 12V or 19V DC.

[mihai_apc]

voidstar , I'm referring to what a laptop power adapter can do in case the input voltage goes overboard, say 250V AC (something the Line-R can help with, for example).

[voidstar_apc]

Agreed, the Line-R can help if the voltage goes above the power adapter's 240V limit.