hoohloc Posted August 25, 2020 Posted August 25, 2020 Hi Guys My installation has the 60A MCB between my load and the Earth Leakage. I'm out of space and want to install a contactor so that I can isolate my geyser and stove during load shedding and use N/c contact to power a pilot light so that I can be aware when there is no mains supply. The only way I can achieve this is by removing the 60A MCB and my question is, is it ok to remove it and use the E/L as main switch? I honestly don't see the need for it Quote
Louisvdw Posted August 25, 2020 Posted August 25, 2020 You can use the the Earth Leakage as the main switch as well. Mine is wired like that. See the last image in this post Quote
hoohloc Posted August 25, 2020 Author Posted August 25, 2020 14 minutes ago, Louisvdw said: You can use the the Earth Leakage as the main switch as well. Mine is wired like that. See the last image in this post Thank you for the quick response, I was worried and now I'm happy that i can carry on with my project Louisvdw 1 Quote
___ Posted August 25, 2020 Posted August 25, 2020 (edited) 1 hour ago, hoohloc said: is it ok to remove it and use the E/L as main switch? Hang on, not so fast... You must have both 1) overcurrent protection, and 2) residual current (aka earth leakage) protection. You do get combination overcurrent/rcd devices, but they are quite costly, so in most cases your house will be fitted with individual breakers, a 60A main breaker for overcurrent protection, followed by a 30mA RCD. It is unlikely that you have overcurrent protection on that RCD (due to cost factor), so it is NOT as simple as just removing one of them. Edited August 25, 2020 by plonkster PJJ 1 Quote
hoohloc Posted August 25, 2020 Author Posted August 25, 2020 5 minutes ago, plonkster said: Hang on, not so fast... You must have both 1) overcurrent protection, and 2) residual current (aka earth leakage) protection. You do get combination overcurrent/rcd devices, but they are quite costly, so in most cases your house will be fitted with individual breakers, a 60A main breaker for overcurrent protection, followed by a 30mA RCD. It is unlikely that you have overcurrent protection on that RCD (due to cost factor), so it is NOT as simple as just removing on of them. Eish! that means I will have to replace my Earth leakage with one that has both overcurrent and earth leakage protection Quote
___ Posted August 25, 2020 Posted August 25, 2020 56 minutes ago, Louisvdw said: See the last image in this post So I did that... last time I saw that image I ignored it, assuming you had the overcurrent aspect covered. I looked up the spec sheet for the KRC3... it's has no overcurrent protection. You better fix it... ABB makes some nice RCBOs (that do both). Louisvdw 1 Quote
Louisvdw Posted August 25, 2020 Posted August 25, 2020 5 minutes ago, plonkster said: You better fix it. Hmm interesting. I wonder how they got an COC for that. Quote
___ Posted August 25, 2020 Posted August 25, 2020 (edited) 11 minutes ago, Louisvdw said: Hmm interesting. I wonder how they got an COC for that. Oh, when I moved into this house it was the same. Note the CBI breaker to the right. If it has two green levers, it is a switch. It must have green+white combination to have overload protection. The previous owner spent over 10k to get things right, and then got CoCs for all the DBs (three of them)... and this was still overlooked. Edited August 25, 2020 by plonkster Quote
hoohloc Posted August 25, 2020 Author Posted August 25, 2020 48 minutes ago, plonkster said: So I did that... last time I saw that image I ignored it, assuming you had the overcurrent aspect covered. I looked up the spec sheet for the KRC3... it's has no overcurrent protection. You better fix it... ABB makes some nice RCBOs (that do both). I think Growatt has overcurrent protection Quote
___ Posted August 25, 2020 Posted August 25, 2020 14 minutes ago, hoohloc said: I think Growatt has overcurrent protection It probably does, in the sense that if you overload it it will switch off. But when it is in bypass mode (passing through the grid) I'm not so sure. Most inverters require that you install external overcurrent protection. Besides, it still won't pass a CoC. Quote
hoohloc Posted August 25, 2020 Author Posted August 25, 2020 58 minutes ago, plonkster said: It probably does, in the sense that if you overload it it will switch off. But when it is in bypass mode (passing through the grid) I'm not so sure. Most inverters require that you install external overcurrent protection. Besides, it still won't pass a CoC. Thanks for the help, much appreciated. Will have to go with the ABB Earth leakage the, I have no choice Quote
___ Posted August 26, 2020 Posted August 26, 2020 11 hours ago, hoohloc said: Thanks for the help, much appreciated. Will have to go with the ABB Earth leakage the, I have no choice The one I linked is just an example (an only 32A) and it is rather expensive. But the CBI combination breaker is usually around the 1.5k mark, and the last ABB RCBO I bought was around the 1k mark, so that's where you're looking. It doesn't have to be that one of course, shop around a bit hoohloc 1 Quote
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