UPS experience? I'm looking for a new one...

Hi,

My old Mustek USB 1000Va UPS is (eventually) dead. Now i'm looking for a new one. The UPS suitable for me must have good voltage-stabilization system so that it outputs high-quality electric current when on-line and when on battery. It should keep my system (unRaid server box + PC + Network Gear) running for about 6-8 minutes so it must be around 1000Va (know that from my experience). It should also have at least RS-232 port to turn the computers down when needed. Which ones do you recommend?

Thanks in advance.

I would suggest an APC brand, either new or used will do.  I use one with my unRAID server connected by a USB connection.  I added the apcupsd "package" and powerdown packages to my server to allow the UPS to safely and cleanly shut my server down in an extended outage.

Mine is a APC-BACK_UPS ES 750. It gives me about a 7 minute run-time when power is lost.

I only power the server, not any PCs, so I have a smaller size unit than you describe.

here is the output from the UPS via the apccontrol command

root@Tower:/# apcaccess status

APC      : 001,039,1002

DATE    : Tue Dec 02 06:06:39 EST 2008

HOSTNAME : Tower

RELEASE  : 3.14.3

VERSION  : 3.14.3 (20 January 2008) slackware

UPSNAME  : Tower

CABLE    : Custom Cable Smart

MODEL    : Back-UPS ES 750

UPSMODE  : Stand Alone

STARTTIME: Mon Nov 24 08:55:02 EST 2008

STATUS  : ONLINE

LINEV    : 119.0 Volts

LOADPCT  :  51.0 Percent Load Capacity

BCHARGE  : 100.0 Percent

TIMELEFT :  7.7 Minutes

MBATTCHG : 5 Percent

MINTIMEL : 3 Minutes

MAXTIME  : 0 Seconds

SENSE    : Medium

LOTRANS  : 092.0 Volts

HITRANS  : 139.0 Volts

ALARMDEL : Always

BATTV    : 13.8 Volts

LASTXFER : Low line voltage

NUMXFERS : 2

XONBATT  : Sun Nov 30 01:25:49 EST 2008

TONBATT  : 0 seconds

CUMONBATT: 4 seconds

XOFFBATT : Sun Nov 30 01:25:51 EST 2008

SELFTEST : NO

STATFLAG : 0x07000008 Status Flag

MANDATE  : 2008-01-13

SERIALNO : 3B0802X63649

BATTDATE : 2001-09-25

NOMINV  : 120 Volts

NOMBATTV :  12.0 Volts

NOMPOWER : 450 Watts

FIRMWARE : 841.I2 .D USB FW:I2

APCMODEL : Back-UPS ES 750

END APC  : Tue Dec 02 06:07:19 EST 2008

Are you sure it is dead?  UPS batteries have to be replaced every 3 to 4 years.... if you don't it can appear dead.  (I'm actually replacing my secondaries this week)

The VA/Wattage rating doesn't have anything to do with runtime on battery.  You need to chose the wattage based on the load of the systems you are running... then chose battery size to achieve the appropriate run time.

Also, you should chose based on Watts, and not VA.... VA ratings do not take into account power factor losses and inefficiencies.  Add up the wattage of all the devices you want to power, and chose a UPS that will provide that many Watts.... then chose battery size based on the number of Watt-hours of runtime you need.

My personal preference is for APC Smart-UPS units in the XL series, that can use additional external batteries.

Are you sure it is dead?  UPS batteries have to be replaced every 3 to 4 years.... if you don't it can appear dead.  (I'm actually replacing my secondaries this week)

 

The VA/Wattage rating doesn't have anything to do with runtime on battery.  You need to chose the wattage based on the load of the systems you are running... then chose battery size to achieve the appropriate run time.

 

Also, you should chose based on Watts, and not VA.... VA ratings do not take into account power factor losses and inefficiencies.  Add up the wattage of all the devices you want to power, and chose a UPS that will provide that many Watts.... then chose battery size based on the number of Watt-hours of runtime you need.

 

My personal preference is for APC Smart-UPS units in the XL series, that can use additional external batteries.

Batteries are probably also dead, but it shouldn't affect (should it?) the output voltage since the device is equipped with AVR system.

By the way how do AVR systems work in APC devices? Is the voltage almost perfect all the time?

I've found an ETA brand UPS which looks very suitable for me. It's "multisystem UPS 1000L" What makes it very advantageous is lack of (needless) software bundled and good parameters. Also, the great advantage is that ETA UPSes can us APC's signals on RS232 which makes them compatible with apcupsd.

What do you think of that?

Personally I thin you will live to regret not buying APC. Every problem ive ever had with a UPS has been on a brand other than APC.

Batteries are probably also dead, but it shouldn't affect (should it?)

Ohhh YES it will.  UPSes are devices intended to provide "fault tolerance."  How would you like a UPS to appear to work normally, when the batteries were shot?  You think all s fine, until the power drops out, and wham... the UPS is worthless.

Bad batteries can also act as shorts to the charging circuit, which will make a UPS appear to immediately power off, or not even start up, due to an overcurrent/safety interlock.

You can try disconnecting the batteries completely, and then plug in the UPS... for some UPS units, that will give you a start-up alarm condition, that shows the box is at least alive.

I also second the recommendation of APC.  Easily replaceable batteries.  Some of my units are nearly 20 years old, with batteries replaced every 3-4 years.

BTW, another tip.

Put a sticker on the front of EVERY UPS, with the date the batteries were last changed, the date of the last run-down test, and the results.

Test them annually, with a rundown test.

A halogen work lamp makes a great full load for rundown tests. You can get either 300 or 500 watt bulbs for them. Just remember to use your UPS's max wattage, not VA rating when conducting full load testing.

If you are going to all the trouble of doing loaded rundown tests, you should test your shutdown capability at the same time by plugging your server into an unswitched outlet and allow it to see the USB or serial output of the UPS to see if it shuts down before the UPS actually runs out of power. Ideally the server should send a signal to the UPS to shut its output off after the server has shut down. Then when you return power to the UPS, it should power the load again.

Also remember that a UPS needs its ground wire to be connected when you kill power. You can get away with just pulling its supply plug out of the wall most of the time, but you run the chance of killing it. An approved method would be to plug it in to a power strip with a switch, power up the UPS and switch on the temporary load, turn off the switch on the power strip and allow the load to run down the UPS until the server shuts itself off.

Thanks for your suggestions, now it seems like the best option for me is to buy new battery pack for the old UPS and use it to power my PC only, and buy an APC UPS to power my server. I can buy second-hand APC Smart-UPS 750VA USB & Serial 230V for 500z? = 166$ the salesman says the UPS has got new battery installed and calibrated. Is it worth?

Here's my personal setup:

unRaid server with 8 drives

PC with monitor/speakers/etc.

DSL modem

Wireless router

Gigabit switch

I have all of these plugged into the following APC UPS:

APC BR1300LCD 1300VA 780 Watts 8 Outlets BACK-UPS

http://www.newegg.com/Product/Product.aspx?Item=N82E16842101066

The server and the PC stay on 24/7.  In the event of a power failure (after 2 minutes of running on battery backup), the PC automatically runs 'powerdown script' from within WinXP to shut down the server cleanly, then automatically shuts itself down.  This works well for me because I have my server and PC in the same location.

The used Smart-UPS 750VA is a decent deal, if the batteries are indeed new.  Personally, I use the XL-series from APC, so I can add additional batter packs to my main desktop system, and the other APC units (unRAID, Asterisk, home automation) are considered emergency replacements for my desktop UPS.

For miscellaneous small devices like switches, I usually use something small (300 Watts) picked up used locally for about $20.