SURT2000XLI problem diagonistic

[Hottest_Fudge_apc]

This was originally posted on APC forums on 4/3/2015

---

Hi there,

I have had a Smart-UPS attached to some devices and the devices have been reading that there are "voltage distruptions". The problem happens rarely (2 times a month at most and only at night so can't see if the battery is discharged). I have had the equipment the UPS supplies checked for faults and there didn't seem to be any, so I was wondering if it was the UPS which could be failing? The load on the UPS is only around 1000W below its limits. How could I go about diagnoising the fault (if there is one) what should I check? The UPS is only 1 and a half years old and none of the error LEDs are illuminated.

Many Thanks,

Hottest Fudge

[BillP]

This reply was originally posted by Angela on APC forums on 4/3/2015

---

What do these devices consider "voltage disruptions?" Meaning, does the voltage need to fluctuate more than 4V, for example? It'd be helpful to understand what your devices are looking at specifically.

It is normal for the UPS's output voltage to fluctuate slightly within a defined range that they can operate in so it is tough to say what it is if we don't know what your devices are looking at.

It'd also be good if you had a Network Management Card or PowerChute Business Edition and could check the event/data log at the times your devices report a problem.

[Hottest_Fudge_apc]

This was originally posted on APC forums on 4/7/2015

---

Thank you very much for your prompt reply! And sorry for my delayed one...

I will check with the manufacture as to what is the minimum amount of voltage distortion that gives the error. As for the UPS I have read that the output voltage distortion is < 3% (so 230 +/- 6.9V or +/- 3.45V), which is correct?

The UPS is currently in a rather secluded place and with no access to the network. Although there is a closed network PC (not connected to internet) do you think it would be prudent to set up the powerchute software on that, also how helpful would the software be?

Could my problem perhaps be that, if or when there is a power cut, the UPS isn't quick enough to change from mains power to battery power?

Many Thanks,

Hottest Fudge

[BillP]

This reply was originally posted by Angela on APC forums on 4/7/2015

---

Hi again.

What I see for this UPS in regards to output voltage distortion (and other items) is:

Output voltage selections	220, 230(default), 240V
Output voltage regulation range	+/-1% (typical)
Output frequency range	50/60Hz +/- 3Hz (default); 50/60Hz +/- 0.1Hz (user selectable)
Output voltage distortion	<3% linear, <8% non-linear
Number of output phases	1 phase
Nominal output current (Amps)	8.7

It is hard to guess what the issue is without knowing what the equipment looks at. This is an online UPS so it has 0ms transfer time to battery power so I doubt that is related.

If we have no idea what the equipment is looking at, you could set up PowerChute but I think understanding what the tolerance of your equipment is first will be helpful and a good start. PowerChute may not catch something that only lasts for 1 second depending on what it is and maybe depending on the answer to the tolerance of the equipment will explain normal operation of the UPS.

[wayne_i_apc · Accepted solution]

This was originally posted on APC forums on 4/7/2015

---

Hi Mr Fudge (?!),

In your first post you speak of "voltage distruptions", while in later posts the discussion is about "voltage distortion". Notice in the specifications that Angela provided the "output voltage regulation" is listed as +/- 1% and "output voltage distortion" can be almost 8% in specific cases. While these are good numbers for AC power to a computer system (probably even better than utility (mains) power), if the output voltage regulation was 8% it would be disappointing for a UPS output of this class. On the other hand, a step-approximation output UPS doesn't even list output voltage distortion as a specification because it would horrify anyone who didn't understand the meaning of "distortion" while the UPS output is still acceptable for most computer systems.

Returning to you original post, can you be more specific about what your "attached devices" are, and how are they "attached"? Are they powered by the UPS in question, and are they connected to it's communication system (communication port or network management card)? How are they "reading" these "voltage disruptions", are they actually monitoring the UPS output directly, as in a powerline monitor system? And what does "voltage disruptions" mean?

When you say it happens "2 times a month", I would be suspicious of a scheduled self-test (I believe 14 days is the default self-test schedule), with a switchover to utility when testing the bypass feature possibly causing a glitch in the UPS output. Otherwise, as Angela already said, there is NO transfer time-- this type of UPS operates contiunously on it's inverter, so ANY problem (voltage, frequency, distortion, noise) with utility power will have absolutely NO effect on it's output! It's like utility power only supplies the input to a very large "battery charger", while the UPS runs continuously from the "batteries".

Wayne