Problems with surge protectors?

Howdy folks! Glad I found this forum, great info all around. I've done some looking around but havent been able to locate a thread that would help me so I decided to post my own.

We recently installed a 20KW PV system on opur office using two Fronius 11.4.3 inverters with Kyocera KD210GX-LP panels. The average run from panels to inverter is 70 feet with the run from inverter to grid tie-in is less then 10 feet. All legs of power (3 phase system) are coming out between 122 and 125 volts. Amp draws have me a little confused though.. Legs 1 and 3 were putting out 3 Amps while leg 2 was putting out .3 Amps. There were a lot of clouds out and it was 9 AM when I checked all these.

Our problem seems to be that our surge protectors in the office keep "Clicking". They are not tripping but all of them keep making a clicking noise at random and each at its own time. Also, randomly computer/printers will freeze/restart. We have only been having these problems for the last 2 weeks since we tied and system in.

My question is, Is there any known issuse like this? Or can anyone perhaps give me some ideas as to what the problem is? If you guys need anymore information I am more then capable of getting it for you.

P.S. I just got off the phone with our power company and all they were able to tell me is that I have a 3 phase 120volt feed in with 200 AMP service. I asked to have an engineer to call me back but they said it would be a few days to a week before I get a all back.

Any help would be great as this is the frist time I've ever messed with a PV system.

P.S.S. Do you guys know any sites that have a buttload of info on solar? Need to get knowledgeable on this topic.

Thanks, O'Michael

Comments

  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    Re: Problems with surge protectors?

    Which surge protectors are installed?

    For a lot of basic info, try www.homepower.com
  • System2
    System2 Posts: 6,290 admin
    Re: Problems with surge protectors?

    Wow, great site thanks. Eyes are hurting already from staring at a computer for a few hours.

    The surge protector is from a compnay called APC with the only writing I could find without having to unplug everything was "APC Battery backup/Surge protection".

    Do you think the fact that its a Battery backup might be the problem? Also, I went around to some of our other work stations with different surge protectors on them and nobody has heard the clicking sound.

    Anyone got any ideas as to why the second leg would only be pushing .3 amp? Seems like it should be in line with the other to legs to me but I honestly dont know.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Problems with surge protectors?

    Your "surge protector" is a UPS - Uninterruptible Power Supply. The clicking is the relay trying to switch over because it perceives "bad power". There are sensitivity adjustments for this, but the problem is probably a bad neutral/ground connection in the wiring. I've experienced exactly that with my APC unit.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Re: Problems with surge protectors?

    From the Marketing Lit:
    Three efficiency peaks
    Greater power harvest for every system size: The unique automatic transformer switching function of the Fronius IG Plus makes enables not one, but three equal efficiency peaks. The result: Consistently high efficiency over a wide input voltage range.

    In comparison: The efficiency of inverters without transformer switching declines steadily with an increasing input voltage. Devices without a transformer only have one efficiency peak.

    With a 96.2 % maximum efficiency, the Fronius IG Plus series scores the highest grade among HF devices.

    MIX™ Concept

    Get the maximum power harvest out of partial load ranges, e.g., on cloudy days, through a clever combination of multiple power stages in each inverter. The power stages in Fronius inverters divide up the work depending on operating hours and only operate as many power stages as required to efficiently process available power from the PV array.
    It almost sounds like during periods of low collection--that the unit will not run "all three converters" but just one or two... So, it is possible that you will see unbalanced output on your three phases.

    One there is a minimum amount of solar power available--then all three converters will energize and you should see balanced power output.

    By the way, how are you measuring the current in the legs? 3 phase power does not necessarily add current in a simple way. Are you reading the GT Inverter's LCD display for the L1/L2/L3 outputs? There should also be other information (total power, line/phase voltage, etc.).

    Also, I would guess if you have 3 phase Delta power--your inverter is operating at 240 VAC--not 120 VAC. So, your "total power" reading at that time should have been around:

    3a * 240 VAC = 720 watts
    3a * 240 VAC = 720 watts
    0.3a * 240 VAC = 72 watts
    ====================
    Total = 1,512 watts

    Regarding the surge suppressors Marc/Cariboocoot and your descriptions of "batteries" is that these are UPS (uninterruptable power supplies). Basically, they pass AC power from the utility to the computer when all is OK, and turn on an internal inverter (battery power) when it detects if the power is bad.

    There are also versions that have transformers inside them that take a wide range of input voltage (something like 95-136 volts or so) and with a variable tap transformer will switch it closer to a stable 120 VAC. I do not know--but in a quiet office you may be hearing each time it changes tap voltage (enough change in input voltage to change the transformer settings, but not bad enough to cause the UPS portion to turn on).

    Will switching the taps on the transformer cause computers to freeze--It should not, otherwise the "solution" (transformer) is worst than the "problem" (variable input voltage).

    The reason you may be hearing more "clicks" (this is just guessing) is that the voltage point was just above your average utility voltage (more load, a big of sag, was not enough to change the transformer tap). Now, your solar power system, during the day, is enough to raise the building voltage a bit (20 kWatts of power from a the array causes a "voltage rise" in the wiring). And anytime there is changes in the sunlight (clouds, etc.) or other loads (A/C, etc.)--It is causing the UPS's to switch.

    In any case, you probably need to get the model number(s) of the UPS's that are clicking and look up their specs/manuals and see exactly what they are.

    Again--the above is all just wild guesswork on what I have read so far--more information would be helpful.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Problems with surge protectors?

    From the OP's description figured it was the same sort of battery-based APC unit I have, and that the "clicking" problem might also be the same. Be advised it also "clicks" when loads change the line voltage a bit - even set down in sensitivity - so Bill's insight is probably correct.

    Ironic, isn't it? The computers' own supplies are better able to cope with power fluctuations than the "protectors" we buy to protect them!

    I originally got mine to protect the comp when the power went down if the generator ran out of gas (while powering from gen). The inverter doesn't switch back on fast enough in those circumstances, but the UPS will. Disconnect the gen power and the inverter takes over fine; it's just if the line voltage "ramps down" as the generator runs out of fuel (or is suddenly over-loaded by the water pump kicking on) that there's a problem. You might say it can handle on/off but not "going low".
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Re: Problems with surge protectors?

    By the way--as I was thinking about your discription and the marketing lit description (transformer in the GT Inverter allows the GT to have 3 peaks in the efficiency curve--my guess that they shut down one or two of the inverter sets to keep efficiency up may very well be wrong)--anyway more thinking (hey--got to start somewhere :roll:) made me think of this very long Fronius Thread:

    Fronius MPP Hunting

    You may be hitting another issue related to the above thread... The Fronius is hunting and its output current/voltage changes--and the UPS (and other constant power loads) are hunting/responding to what the GT Inverter is doing.

    Constant Power Devices (computer power supplies, and motors to a degree) follow the P=I*V equation... P (power) is fixed, and as voltage falls, current consumed must go up to ensure that the device consumes "constant power".

    You can get into "unstable" operating points between the power sources and the loads (or positive feedback loops). Basically, For example, the GT Inverter does something that causes voltage to go up (say it is generating more power/current as the sun comes out)--The computers see higher voltage and draw less current, and the voltage goes up even more. And a similar thing can happen as the voltage drops (clouds), the computers must draw more current to keep power use constant.

    And--this "feedback loop" may be on the order of a few seconds, or it could happen 120x per second (every 1/2 cycle of 60 Hz AC). Couple that to an issue with the inverter possibly "MPPT Hunting" -- you can have a very difficult issue to diagnose (see the thread at top--turned out that this took a lot of work and the vendor admitted there are some design issues with that model of inverter).
    mradtke wrote: »
    ... At some point a Fronius engineer talked about the performance hole being related to an MPP in the area of 230 volts with a high AC line voltage of around 250 volts.

    I haven't heard anything more from Fronius on their recently promised fix....

    There can be multiple issues... In the above case, it appears with Vmp~230 volts and Vac~250 volts--the inverter tends to hunt (and cause variable AC output power with constant Parray input.

    And, as always--just guessing and offering suggested diagnostic paths to follow. I have no insight into your installation/GT hardware other than what you see here. :confused:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • westom
    westom Solar Expert Posts: 28 ✭✭
    Re: Problems with surge protectors?
    From the OP's description figured it was the same sort of battery-based APC unit I have, and that the "clicking" problem might also be the same. Be advised it also "clicks" when loads change the line voltage a bit
    An APC is made so cheaply that replacing only its battery costs almost as much as the entire unit.

    Read its numeric specs. Its protection is near zero. But a "near zero protector" gets advertised to those who ignore numbers as "Surge Protector". Reality. The APC is not a surge protector. Or more accurately, it is a near zero surge protector.

    So cheap that even irrelevant line noise can upset (or trigger) its battery backup control circuit. That UPS is intended for use on AC mains that are some of the 'cleanest' power an appliance will see. Demonstrated is how the APC responds when even minor variations from 'clean' occur.

    Manufacturer assumes you will ignore numbers; instead believe subjective claims. That is how junk science gets promoted. Read its specs. It is a near zero surge protector.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Problems with surge protectors?

    Westom - I know! A couple of MOV's is about it for the APC. Fortunately I didn't buy it for that reason. I bought it to provide back-up in case the gen went out suddenly. For that purpose it serves. But yes, the batteries are more expensive to replace than the whole thing.

    BTW, when running off the inverter it's as well-behaved as can be. It's only the generator's inability to react quickly to load changes that cause the APC to 'click' now. This may well be related to the OP's problem; fluctuating line voltage due to the grid-tie inverters "hunting" as Bill suggested.

    Thing had fits all the time when I tried to feed it off the old Xantrex MSW inverter. It viewed that power as "dirty".
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Re: Problems with surge protectors?

    Feeding a UPS from an MSW Inverter can have its own issues...

    MSW inverter wave forms do not have the high/peak voltage that a size wave has (~120 volts peak vs ~170 volts peak of a True Sine Wave)--many/most circuitry has simple comparators to "check" the input voltage instead of a a true RMS (Root Mean Square) circuit to measure the potential energy of the wave form.

    However, that should not be an issue with the OP's original post. The Grid Tied inverters are True Sine Wave inverters (as good as "average" grid power) and MSW vs TSW wave forms are not an issue in this installation.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Mangas
    Mangas Solar Expert Posts: 547 ✭✭✭✭
    Re: Problems with surge protectors?

    I have four APC surge protectors in different rooms with no observed audible problems or otherwise.

    I am considering removing them as I was told the four inverters have a more dependable power output than if I were on the grid subjected to those spikes which are numerous in our rural area.

    Don't know if this is correct but am unsure whether to disconnect ours or not.
    Ranch Off Grid System & Custom Home: 2 x pair stacked Schneider XW 5548+ Plus inverters (4), 2 x Schneider MPPT 80-600 Charge Controllers, 2 Xanbus AGS Generator Start and Air Extraction System Controllers, 64 Trojan L16 REB 6v 375 AH Flooded Cel Batteries w/Water Miser Caps, 44 x 185 Sharp Solar Panels, Cummins Onan RS20 KW Propane Water Cooled Genset, ICF Custom House Construction, all appliances, Central A/C, 2 x High Efficiency Variable Speed three ton Central A/C 220v compressors, 2 x Propane furnaces, 2 x Variable Speed Air Handlers, 2 x HD WiFi HVAC Zoned System Controllers