mohfamous Posted April 4, 2018 Share Posted April 4, 2018 Hello all my inverter ks 1000VA, voltage output without load is 228V, when I put load on the ouput decreases to 108V, what do you think the problem? Quote Link to comment Share on other sites More sharing options...
Guest Posted April 4, 2018 Share Posted April 4, 2018 1 hour ago, mohfamous said: ... 228V, when I put load on the ouput decreases to 108V ... I presume you mean the output volts? Could be that the batteries cannot take the load, massive drop in battery volts and amps, thereby dropping the inverters volts. Quote Link to comment Share on other sites More sharing options...
pilotfish Posted April 4, 2018 Share Posted April 4, 2018 2 hours ago, mohfamous said: when I put load on the ouput decreases to 108V, Where are you measuring? Measure directly on the L+N output terminal of the inverter, if still 108v then the inverter is faulty - there is no ways that any inverter should allow a voltage drop of that nature without dropping out. Chris Hobson and ___ 2 Quote Link to comment Share on other sites More sharing options...
mohfamous Posted April 4, 2018 Author Share Posted April 4, 2018 3 hours ago, The Terrible Triplett said: I presume you mean the output volts? Could be that the batteries cannot take the load, massive drop in battery volts and amps, thereby dropping the inverters volts. I have measured the battery (12V / 100AH @c20) was 12.8 volts and the load 36W. Quote Link to comment Share on other sites More sharing options...
mohfamous Posted April 4, 2018 Author Share Posted April 4, 2018 1 hour ago, pilotfish said: Where are you measuring? yes I measure directly from L N Quote Link to comment Share on other sites More sharing options...
___ Posted April 4, 2018 Share Posted April 4, 2018 My first gut feeling is to plug in something that will visually tell me if I'm seeing the right thing. An incandescent lamp for example. That will visually go dimmer when the voltage drops, and because power is proportional to the square of the voltage the effect will be dramatic: It should be about a quarter of the normal brightness at 100V. The only other thing (other than that the unit is damaged) that occurs to me is that MSW inverters (far as I know this is not one) behave like this because cheaper non-RMS multimeters measure an average across a signal it assumes to be sinusoidal, ie RMS is at 1/sqrt(2) or 0.707 of peak, but when the output is not sinusoidal the voltage will be way off and will vary according to load and battery voltage. Quote Link to comment Share on other sites More sharing options...
Guest Posted April 4, 2018 Share Posted April 4, 2018 2 hours ago, mohfamous said: I have measured the battery (12V / 100AH @c20) was 12.8 volts and the load 36W. I know that a battery can show perfect volts, until it is put under load. Then volts drop like a rocket under power going the wrong way. Would test the batteries individually of you can, under load, using a load tester to eliminate them as a potential cause. 2 hours ago, pilotfish said: ... there is no ways that any inverter should allow a voltage drop of that nature without dropping out. I also concur with Pilotfish - inverter should stop working or is faulty. Or, inverter does not have that built in. Just keeps going like a UPS inverter I once tested, as Plonkster also alludes to. Plonksters idea of a light is a good test. Have seen on my inverter where it overloads for a number of seconds, the watts, in my case, dropping from average of 800w, peaking at over 2000, then dropping to 45w, before it recovers. UPS'es at that time protecting the loads. At the time I get overload and low battery volt warnings. Not a good idea (in my case) to have fridge + freezer start up same time a load of 750w is powered on a inverter that is rated at max 1600va. Quote Link to comment Share on other sites More sharing options...
___ Posted April 4, 2018 Share Posted April 4, 2018 2 hours ago, The Terrible Triplett said: Not a good idea (in my case) to have fridge + freezer start up same time a load of 750w is powered on a inverter that is rated at max 1600va. I remember you asked me about that. I've had conditions like that too. The UPS of course attempts to hold the voltage up, but even without the UPS, most appliances don't mind the temporary drop. I was out in my backyard the other day pumping water from the well while my water-treatment circulation pump was also running. So I had a bunch of stuff running already, including the 500W circulation pump, when the grid failed just as I turned on my 850W well pump. Same inverter as yours. Well, there was one almighty dip in the power and I swear the inverter must have groaned something fierce... but it picked up the load and while I was still a little perplexed as to why the one pump seemed to blip like that my wife arrived to ask if I know about the power failure... I am incredibly pleased with this 1600VA Multiplus. I mean, it is not difficult to overload it if you want to, but it is remarkably resilient to accidental overloads. A bit off-topic though. This 1000va KS model is a 12V pure sine model. Quite possibly has something broken and the high voltage DC bus is sagging for whatever reason. It might well be some kind of failure. Quote Link to comment Share on other sites More sharing options...
Guest Posted April 4, 2018 Share Posted April 4, 2018 42 minutes ago, plonkster said: I swear the inverter must have groaned something fierce They do. :-) I just got a bit worried when it happened a number of times per day, cannot be good in the long run. The voltage drop, it is very annoying with computers, internet and screens. Bar the fact that you hear the noise, you see it too. 1 hour ago, plonkster said: Quite possibly has something broken and the high voltage DC bus is sagging for whatever reason. If the batts are fine, the cables to specs, then all that is left is the inverter. Quote Link to comment Share on other sites More sharing options...
___ Posted April 5, 2018 Share Posted April 5, 2018 16 hours ago, The Terrible Triplett said: The voltage drop, it is very annoying with computers, internet and screens No problems here. At most the AV-receiver in the living room will activate it's speaker-pop protection (that relay that connects the speakers after the amp has started). Quote Link to comment Share on other sites More sharing options...
Guest Posted April 5, 2018 Share Posted April 5, 2018 26 minutes ago, plonkster said: At most the AV-receiver in the living room will activate it's speaker-pop protection (that relay that connects the speakers after the amp has started). O really. At most he said. On this subject, I am a Master. TV - goes off - have to switch it on again. Computer Screens - 24" ones go off then comes on again. Older 27" stays on, just flickers - has a larger PSU. Mikrotik - reboots. Fibre - reboots. DSTV - have to switch it on again. QNAP - reboots. It all depends on the size of the caps in the PSU I deduced. The newer smaller 2 prong plug PSU nowadays are not designed to keep things on like for example a computer PSU can. Thats why they are so cheap, for obviously, the loads are so much lower. Therein the 2nd reason for the APC 2200VA online UPS between inverter and precious loads. The 24/7 off-grid loads direct on inverter are on separate small inline UPS. Got seriously tired of the shocked shouting in the house as in: "DAAAAAD!!! What did you do NOW!?" ... having touched NOTHING! EDIT: O, I forgot. The Wife's Xeon 1U blade server goes off. PSU is too small as it is designed to be lean and mean at +-100watts. Mine, same specs, also +-100w when on, in a tower case, has a bigger PSU, it will keep powering through the dip. Quote Link to comment Share on other sites More sharing options...
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