February 22, 20179 yr I am building a garage/ workshop it will have is own CU I oder a 3P +N RCBO from aliexpress but they send me a 3P RCBO can I use this one or better to oder a new? shold I use the same earth rod from the house or fit a new it is about 15 meters between them?
February 22, 20179 yr Some experts will visit shortly, but I recently built the same sort of thing about 30m from the house. I treated it as a new installation as (mine only single phase), the underground power feed is from the incoming mains. So I did put an earth rod from the new garage CU. I haven't looked up the RCBO 3P + N, but I presume it open circuits the N as well on a trip. If this is the case I'm not sure why you require it on a garage installation.Sent from my SM-J700F using Tapatalk
February 22, 20179 yr @Boostjunky can you post a photo of the device they supplied please. I would use a separate rod but do NOT link N-E in the outbuilding CU. "I don't want to know why you can't. I want to know how you can!"
February 23, 20179 yr OK, that's a 3-P RCBO intended for operation of balanced 3-phase loads with no neutral (motors and the like). I do not believe it is suitable for the application you intend where there will be significant neutral currents. Time to open a dispute with the supplier I think if they definitely sold it as 3P+N. "I don't want to know why you can't. I want to know how you can!"
February 23, 20179 yr I just went to the Aliexpress website. https://www.aliexpress.com/wholesale?ltype=wholesale&d=y&origin=y&isViewCP=y&catId=0&initiative_id=SB_20170222185203&SearchText=3P+%2BN+RCBO&blanktest=0&tc=af, and it seems that some of the RCBOs advertised as 3P+N gave a neutral connection and some don't! The picture of the EFET one looks exactly like the one you have and is obviously missing the neutral but is advertised as 3P+N, the picture of the DELIXI advertised as 3P+N has the neutral connection. Both advertised as 3P+N. Doesn't surprise me!
February 23, 20179 yr Author I contacted the seller and he will send me the right one that I oder , so abut10 days befor i get it
February 23, 20179 yr Don't let your option to open a dispute expire. I've seen this ploy from a couple of Chinese sellers, low value stuff so they hope you'll not bother opening a dispute. Item in question was a pack of 10 football adaptors. Only one arrived. "Sorry, sorry, we'll send you the rest" Some time later, after I'd let the dispute time out, another one adaptor arrived So I have two adaptors for the price of 10 (they were really cheap mind). "I don't want to know why you can't. I want to know how you can!"
February 23, 20179 yr I haven't had too much trouble with the sellers on Aliexpress, but always keep the dispute date in mind. However, Lazada customer service is totally useless. I order a lot through Lazada and the majority of the time they perform and deliver before the committed date, but when I have a problem and have to contact customer service they have to be the worst. Getting a refund for non delivery takes a month of Sundays! off topic!
February 23, 20179 yr Just to say... I have ordered a lot from Lazada and the one time I had issue it was resolved by their customer service immediately. They refunded the price and I sent back the defective item.
February 23, 20179 yr Probably silly question, but how can you have a 3 phase RCBO without a neutral? What inbalance causes it to trip? Sent from my SM-J700F using Tapatalk
February 24, 20179 yr 23 minutes ago, Arjen said: I think Crossy gives the answer here? "operation of balanced 3-phase loads" So an inbalance between the phases will make it trip? Nearly. A simple phase imbalance won't trip a 3-phase 3-wire RCD/RCBO (with no neutral the phase voltages will go awry). The RCD device performs a phasor addition of the three phase currents, this should result in zero. If it does not the difference must be going somewhere (through you) and the device operates. The 3-P+N unit does the same sums on the 3 phase plus the neutral (still looking for zero). "I don't want to know why you can't. I want to know how you can!"
February 24, 20179 yr I always wondered about the operating principle of the RCBO...am I right in presuming that it's the same as a differential protection relay in an HV/MV installation?...a low voltage version of detecting ground faults...
February 24, 20179 yr Nearly. A simple phase imbalance won't trip a 3-phase 3-wire RCD/RCBO (with no neutral the phase voltages will go awry). The RCD device performs a phasor addition of the three phase currents, this should result in zero. If it does not the difference must be going somewhere (through you) and the device operates. The 3-P+N unit does the same sums on the 3 phase plus the neutral (still looking for zero). Ahhh, forgotten my 3 phase stuff. Thanks for the response effort.Sent from my SM-J700F using Tapatalk
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