JacquesVDM Posted July 23, 2019 Share Posted July 23, 2019 Hi, I have a Axpert 5kw inverter (Firmware 74.30) with Pylontech batteries. When I start the kettle (or any other 'heavy' load), I see a dip on the lights. It is like a small flicker. Output power is about 200w before I start the kettle. Output voltage is 228V before I start kettle and 226V after the kettle is started. Also when the kettle is switched off, the lights make a flicker. It seems as though the inverter is too slow to react to the sudden load change. Anyone else experiencing it? Is it normal? Thanks Jacques Quote Link to comment Share on other sites More sharing options...
___ Posted July 23, 2019 Share Posted July 23, 2019 1 hour ago, JacquesVDM said: I see a dip on the lights It's normal. The intensity of the light is proportional to the square of the voltage (since P = V*I and I=V/R, so P = V^2/R). So even a 5V dip creates a noticeable flicker. Happens even with higher quality inverters. Quote Link to comment Share on other sites More sharing options...
JacquesVDM Posted July 23, 2019 Author Share Posted July 23, 2019 Sjoe. Had me worried. Thanks for the reply. Quote Link to comment Share on other sites More sharing options...
Fazil Posted July 23, 2019 Share Posted July 23, 2019 if its an issue you can wire a 30A contactor and you dont notice the dip at all. Will cost you about R1500 for a good contactor with aux. Quote Link to comment Share on other sites More sharing options...
Jaco De Jongh Posted July 23, 2019 Share Posted July 23, 2019 2 minutes ago, Fazil said: if its an issue you can wire a 30A contactor and you dont notice the dip at all. Hi Fazil, can you please explain the logic behind this? How does the contactor help with the dip? Quote Link to comment Share on other sites More sharing options...
Fazil Posted July 23, 2019 Share Posted July 23, 2019 34 minutes ago, Jaco de Jongh said: Hi Fazil, can you please explain the logic behind this? How does the contactor help with the dip? we have noticed in our installations that using the contactor that there is no dip. I can have 1 of my engineers give the technical detail. No problem. This is mainly observed on TV and flourescent lights. LED not at all even without the contactor. Quote Link to comment Share on other sites More sharing options...
___ Posted July 23, 2019 Share Posted July 23, 2019 I'm confused too.... Quote Link to comment Share on other sites More sharing options...
Beugleuce Posted August 28 Share Posted August 28 5 years later.... I also see lights dipping when drawing power. Could that be deteriorating electrolytic caps? Quote Link to comment Share on other sites More sharing options...
Coulomb Posted August 28 Share Posted August 28 (edited) It's common to notice the lights flickering slightly as large loads come on or off. Inverters run from batteries have outputs that are nowhere near as stiff as the utility grid. Some lights are more prone to flicker, e.g. the now-ubiquitous LED lights. Capacitors do deteriorate with time and heat, and the capacitors provided in typical inverters are often not great. I recommend replacing some capacitors even when the inverter is new, but few owners can realistically do this. The main DC bus capacitors seem to be pretty reasonable, and I rarely hear of the need to replace these. They are probably not making the flicker worse, as far as I know. Though the flicker I'm talking about is very momentary, lasting less than a tenth of a second, and I would not really characterise that as a "dip". You can't really tell if the light momentarily were brighter or dimmer, it's that short. If you are noticing the lights significantly dimming for more than a tenth of a second, then you may indeed have capacitor problems. Edited August 28 by Coulomb Scorp007 1 Quote Link to comment Share on other sites More sharing options...
esmail-kassir Posted September 17 Share Posted September 17 On 2024/08/28 at 5:42 PM, Coulomb said: It's common to notice the lights flickering slightly as large loads come on or off. Inverters run from batteries have outputs that are nowhere near as stiff as the utility grid. Some lights are more prone to flicker, e.g. the now-ubiquitous LED lights. Capacitors do deteriorate with time and heat, and the capacitors provided in typical inverters are often not great. I recommend replacing some capacitors even when the inverter is new, but few owners can realistically do this. The main DC bus capacitors seem to be pretty reasonable, and I rarely hear of the need to replace these. They are probably not making the flicker worse, as far as I know. Though the flicker I'm talking about is very momentary, lasting less than a tenth of a second, and I would not really characterise that as a "dip". You can't really tell if the light momentarily were brighter or dimmer, it's that short. If you are noticing the lights significantly dimming for more than a tenth of a second, then you may indeed have capacitor problems. I noticed that with my Axpert VM III when the Aircon starts up , actually I felt it dim the fridge motor sound for 1 moment . I belive this issue is not solvable as long as we use high frequency inverters (not the old one with big transformers that can store power ) . anyway I saw peorle use battery like capacitors as a short time UPS or inrush current booster (https://www.forconstructionpros.com/trucks/trucks-accessories/product/11354889/maxwell-technologies-ultra-capacitor-diesel-engine-starter-beats-battery-performance) (not exactly this but the same technology ) Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted September 17 Share Posted September 17 24 minutes ago, esmail-kassir said: I noticed that with my Axpert VM III when the Aircon starts up , actually I felt it dim the fridge motor sound for 1 moment . I belive this issue is not solvable as long as we use high frequency inverters (not the old one with big transformers that can store power ) . anyway I saw peorle use battery like capacitors as a short time UPS or inrush current booster (https://www.forconstructionpros.com/trucks/trucks-accessories/product/11354889/maxwell-technologies-ultra-capacitor-diesel-engine-starter-beats-battery-performance) (not exactly this but the same technology ) It is purely the high surge current of the aircon. If it was an inverter type aircon you won't notice it. Just as an example when my 1.5kw heat pump starts it takes 3min to reach the 1.5kW level and it runs from only a 24V battery 3kW inverter even when there is no PV to help. Yes being old it is the low voltage PV Axpert. I had the fridge door open to see if the light would dim when I started it(LED). No sign of even a flicker. Quote Link to comment Share on other sites More sharing options...
esmail-kassir Posted September 17 Share Posted September 17 6 hours ago, Scorp007 said: It is purely the high surge current of the aircon. If it was an inverter type aircon you won't notice it. Just as an example when my 1.5kw heat pump starts it takes 3min to reach the 1.5kW level and it runs from only a 24V battery 3kW inverter even when there is no PV to help. Yes being old it is the low voltage PV Axpert. I had the fridge door open to see if the light would dim when I started it(LED). No sign of even a flicker. Do you think using inverter aircon is better due to this issue ( so the surge current won’t cause power dip that affects other devices) or it is not harmful for the other appliances Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted September 17 Share Posted September 17 1 minute ago, esmail-kassir said: Do you think using inverter aircon is better due to this issue ( so the surge current won’t cause power dip that affects other devices) or it is not harmful for the other appliances Aircons are known to use an easy 5+ times running power for a few seconds up to the point they are at running speed. No harm to other devices that's why they are used in all A++ rated equipment like fridges, heat pumps etc. It's not just the starting but also the running that is speed/power controller to only do the amount of work required and not run at full power. Quote Link to comment Share on other sites More sharing options...
Bobster. Posted September 18 Share Posted September 18 (edited) 10 hours ago, esmail-kassir said: Do you think using inverter aircon is better due to this issue ( so the surge current won’t cause power dip that affects other devices) or it is not harmful for the other appliances The AC will draw less current. Less stress on your inverter and batteries. In the example you give the fridge motor will not be affected or will be less affected. Last year I replaced my deep freeze. The new one has an inverter. The difference between old & new is big. The old one could draw up to 1.3 kW on start up. The new one (greater capacity) peaks at just 204 W. Over 8 hours the old used 577W, the new used 192W. Edited September 18 by Bobster. esmail-kassir and Scorp007 1 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.