June 20, 20232 yr 18 hours ago, zs1ssm said: Can anyone confirm if the Growatt SPF5000ES does the E/N bond or not ??? @Scorp007 confirmed that the Growatt SPF5000ES does the E/N bonding internally in an earlier post in this thread I am going to assume the Luxpower does the same, perhaps someone who has one could test and confirm?
June 26, 20232 yr On 2023/06/16 at 10:11 AM, Scorp007 said: The E/N bond is only done at the inverter wires and it can be a relay in a DB. It is essential that this bond is only in place when running from battery. It is thus not a permanent bond. I was told by a Sunsynk technical advisor to permanently bond the inverter output to earth. He maintained that this was safer than a bonding relay as the relay could fail. A number of electricians I know who install inverters follow this practice.
June 26, 20232 yr Edit: I now understand the N-E bond is to bond the output of the inverter to neutral when the inverter is not receiving a grid feed. Or if it doesn't have it's own N-E bond. I have heard that at least one electrician say that they don't bother with a contactor/relay and just hard wire it straight. Edited June 27, 20232 yr by rinners Removing faulty logic
June 26, 20232 yr 1 hour ago, rinners said: I have heard that at least one electrician say that they don't bother with a contactor/relay and just hard wire it straight. That electrician gave you dangerous advice not legal not safe should the eskom earth cable be stolen your property becomes the neutral/ earth bond for every house connected to that Escom transformer.
June 26, 20232 yr 2 hours ago, RobM said: I was told by a Sunsynk technical advisor to permanently bond the inverter output to earth. He maintained that this was safer than a bonding relay as the relay could fail. A number of electricians I know who install inverters follow this practice. Mind sharing this Sunsynk technical advisor's name and contact details?
June 26, 20232 yr 3 hours ago, RobM said: I was told by a Sunsynk technical advisor to permanently bond the inverter output to earth. He maintained that this was safer than a bonding relay as the relay could fail. A number of electricians I know who install inverters follow this practice. So this is then the source of advice why there are a number of installers that do it and belief it is the right way. They heard it from someone. Are Sunsynk installers also technical advisors? Edited June 26, 20232 yr by Scorp007
June 26, 20232 yr On 2023/06/20 at 3:35 PM, PsyCLown said: I am going to assume the Luxpower does the same, perhaps someone who has one could test and confirm? The Luxpower does the neutral/earth bond internally i have installed quite a few of the SNA 5000 and all checks show no floating neutral when islanding. I also check each plug point on the essential side with plug tester with mains power switched off and then do tripping time with multitester on RCD (20-35ms on times 5 scale) ( 120-350ms on times 1 scale) and tripping threshold normally between 16-22ma. Edited June 26, 20232 yr by TaliaB
June 26, 20232 yr 3 hours ago, RobM said: He maintained that this was safer than a bonding relay as the relay could fail The electrical life expectancy of general purpose and power relays is generally rated to be 100,000 operations minimum, while mechanical life expectancy may be one million, 10, or even 100 million operations. Edited June 26, 20232 yr by TaliaB
June 26, 20232 yr I stand to be corrected but it seems like off grid inverters like Mecer/Kodak/Luxpower SNE will have the N/E bond internally. On grid inverters normally need the N/E bond.
June 27, 20232 yr 11 hours ago, TaliaB said: The electrical life expectancy of general purpose and power relays is generally rated to be 100,000 operations minimum, while mechanical life expectancy may be one million, 10, or even 100 million operations. I think the main reason Sunsynk are recommending a permanent bond is not because of using a relay itself but because the inverter has no way of knowing if the relay is working or not . I know with a Victron inverter the inverter can pick up if the bonding relay is not working .
June 27, 20232 yr 40 minutes ago, Nexuss said: Sunsynk are recommending a permanent bond Link please.
June 27, 20232 yr 41 minutes ago, Nexuss said: I think the main reason Sunsynk are recommending a permanent bond is not because of using a relay itself but because the inverter has no way of knowing if the relay is working or not . I know with a Victron inverter the inverter can pick up if the bonding relay is not working . @NexussWhere in any documentation do Sunsynk advise to use a permanent bond! According to my knowledge and regulations permanent bond is not allowed. I would not issue a COC if the bond is permanent.
June 27, 20232 yr 56 minutes ago, Nexuss said: I think the main reason Sunsynk are recommending a permanent bond is not because of using a relay itself but because the inverter has no way of knowing if the relay is working or not . I know with a Victron inverter the inverter can pick up if the bonding relay is not working . If they do recommend a permanent bond then they have different documents showing both methods. This is what I have in their manual.
June 27, 20232 yr Just out of interest I find this method in the Sunsynk manual with respect to the MCB on the earth wire at a SPD.
June 27, 20232 yr If you have a 5-wire system from the transformer (3 phase wires, neutral and ground), you should NOT have a neutral-to-ground bond in the service (just like in any other transformer to panel scenario). In fact, a 5-wire feed from the transformer is the BEST and safest electrical system possible. Hence the reason the Sunsynk 3 phase 5 wire inverter does not have a ATS
June 27, 20232 yr 44 minutes ago, VirWat said: Link please. 42 minutes ago, TaliaB said: @NexussWhere in any documentation do Sunsynk advise to use a permanent bond! According to my knowledge and regulations permanent bond is not allowed. I would not issue a COC if the bond is permanent. as @RobM said . this information comes from installers that asked Sunsynk about the issue and were told to permanently bond by their technical advisor. His name is Charles and there was a video on the sunsynk youtube channel where he also recommended permanent bonding. Cant seem to find the video now . Edited June 27, 20232 yr by Nexuss
June 27, 20232 yr 49 minutes ago, Scorp007 said: If they do recommend a permanent bond then they have different documents showing both methods. This is what I have in their manual. @Scorp007 Read that first paragraph a couple of times. Does it make sense? Clearly that "can have a permanent earth" should be "can't have" (print error)
June 27, 20232 yr 10 minutes ago, VirWat said: @Scorp007 Read that first paragraph a couple of times. Does it make sense? Clearly that "can have a permanent earth" should be "can't have" (print error) I have also pointed this out in the past , but it has been like this in every revision of the manual from the very start. You would think that they would correct it if it was a mistake by now .
June 27, 20232 yr 1 hour ago, Scorp007 said: Just out of interest I find this method in the Sunsynk manual with respect to the MCB on the earth wire at a SPD. That is quite interesting it purpose🤔 maybe to protect the SPD from large surge currents
June 27, 20232 yr Did the answers or video indicate for use in ZA? From what I have seen Sunsynk are quite good at saying that connections are to be made to local wiring regulations. I have seen some countries having a E/N bond at each point of supply and then we find in my munic the E/N bond is at transformer and/or kiosk. Would this not make a difference as @TaliaB has pointed out on his comments.
June 27, 20232 yr 2 minutes ago, TaliaB said: That is quite interesting it purpose🤔 maybe to protect the SPD from large surge currents Yes we normally protect with the 2 MCBs on the L and N. They show 3 MCBs.
June 27, 20232 yr 5 hours ago, VirWat said: @Scorp007 Read that first paragraph a couple of times. Does it make sense? Clearly that "can have a permanent earth" should be "can't have" (print error) I've even emailed sunsynk with no response, told them clearly to sort the manual out as well Iv
June 28, 20232 yr Permanently bonding Neutral to Earth at any downstream point at home is just wrong. Period. What is the use then of having a Neutral and an Earth routed seperately if you can connect them together where you think its right? Ill tell you what is wrong, you have just created a parralel path between neutral and earth towards the next upstream bond. So now your earth is a carrier, where it should only be there for fault currents, so that faults can be detected. EDIT: this comment is not directed towards the OP, its just a general remark. Edited June 28, 20232 yr by BritishRacingGreen
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