3 Phase Power

ellyally

Expert Member
Joined
Feb 7, 2013
Messages
4,413
I know nothing of electrics... what I do know is have 3 phase, got house rewired a while ago and electrician put everything on 1 phase saying 3 isn't needed anymore. Still have 3 meters with 3 cable coming in from street, but 2 are turned off and no wires leading out of them into the house. Guy came and did all checks etc and gave certificate
 

greggpb

Expert Member
Joined
Apr 22, 2005
Messages
1,804
Yeah I am on a prepaid with 3 phase, that said the house does draw some power, we are currently spending about R5k a month on electricity, so looking to sort out a 2 things

1)a load shedding solution to enhance the wife happiness factor
2)a solar solution to save some case to improve dads toy buying capabilities.

But tryng to find one solution that bridge's both this gaps. I was thinking somthing tile this..

Solar panels to charge batteries, once the are full excess flow to house and if there is a deficit deficit is draw from eskom,

The question now the sun goes down do you draw from the batters to save cost with the risk of having flat batteries with shedding hits or do you draw from eskom , to ensure power is eskom kuks ?
 

Marvo

Active Member
Joined
Mar 22, 2015
Messages
54
If your house is supplied by 3 phase you can still use a single phase generator by simply bridging the 3 live wires. Am I correct at saying this?
No. With a balanced 3-phase load the neutral current is very low (zero if it's a perfectly balanced linear load). If you common all the phases together and supply the load with a single phase generator the neutral current will then be equal to the load current. You'll almost certainly overload the neutral, start a fire, end up with the insurance claim being declined and your wife will subsequently pack her bags and leave you for pastures greener.

So in a nutshell , electrically it's a really bad idea but socially it could be a means to an end.
 

greggpb

Expert Member
Joined
Apr 22, 2005
Messages
1,804
No. With a balanced 3-phase load the neutral current is very low (zero if it's a perfectly balanced linear load). If you common all the phases together and supply the load with a single phase generator the neutral current will then be equal to the load current. You'll almost certainly overload the neutral, start a fire, end up with the insurance claim being declined and your wife will subsequently pack her bags and leave you for pastures greener.

So in a nutshell , electrically it's a really bad idea but socially it could be a means to an end.
hahahahah classic, I would get a sparky to do all the installation and the like, just need to hide the cooking equipment for the tik(must be the only way my wife can spend 5k on electricity) before they come around.

Just trying to make sure I can speak the Sparky's language before he comes around.
 

aquadat0r

Well-Known Member
Joined
May 6, 2010
Messages
385
I have 3 phase at home. I'm on prepaid. The meter measures the power of all the phases independently. AFAIK, the load doesn't have to be balanced - all my loads are single phase. I could run everything off one phase if I wanted.

The advantage of 3 phase, is that you have more power available - 3 x 60 A = ~ 40kVA., and you can run 3 phase equipment. If you have lots of aircons, pool heater, jacuzzi, etc, then it is handy.

You can't bridge/join the phases together!
@greg_SA, very old post, but just wat to check this out again. I have 3 phases on prepaid coming into the house I recently bought, normal single phase oven is on phase 1, geyser is on phase 2 and the rest of the plugs/lights/pool pump are on phase 3.

Just want to check the following:
1. Phases don't need to be balanced in home? We almost never use the oven, gas stove and geyser runs on every now and again. Therefor I would assume my 3 phases are not balanced.
2. Will I be consuming more kwh by being on a 3 phase supply?
 

Gordon_R

Executive Member
Joined
Jul 5, 2009
Messages
7,236
1. The phases only need to be balanced for the maximum certified load. If you use less than the maximum, it makes no difference which phases you use.
2. No difference in kWh on 3 phase, assuming meter is reading correctly.

If everyone in whole city had the same wiring and load distribution, that might be a problem for the provider (not for the consumer). Usually there is enough randomness between substations and households for this not to be an issue.
 
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