Measuring power use via circuit breakers at the switchboard

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DarthKermit

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#1238898 14-Feb-2015 14:45

Do you have some of that old black rubber coated wiring called TRS?

Your mains switch is exactly the same as the one on my fuse board in our circa 1952 house.

One of these days I'm gonna get a nice new distribution board and have all the TRS ripped out.

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timmmay

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#1238908 14-Feb-2015 14:51

An electrician told me the wiring has all been replaced.

itxtme

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#1238929 14-Feb-2015 15:23

The 'safety' benefit shouldn't be underestimated, in fact any additional outlets added to a circut means that circut is mean to have an RCD installed by the sparky. Funnily enough many arent doing this though, so as not to lose customers because of the additional cost. That article a few weeks back from the guy who cut the power to the caravan and died is a good example of where an RCD at the box would have stopped a death from occurring. Any dodgey appliances, accidental cord cutting (like when installing insulation in a roof) will trip an RCD, but wont necessarily trip a circuit breaker

Interestingly if you sell a house in Australia the board must be done to protect all power plug outlets via an RCD. NZ has its head in the sand somewhat.

timmmay

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#1238931 14-Feb-2015 15:39

Interesting. No electrician has told me I need an RCD. I'll make a note of it and I will get it done at some point, though probably not immediately.

Handle9

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#1238932 14-Feb-2015 15:41

timmmay: Interesting. No electrician has told me I need an RCD. I'll make a note of it and I will get it done at some point, though probably not immediately.

The fun thing is you don't need "an" RCD. You need one every three circuits, like the one fitted for your bathroom.

blakamin

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#1238934 14-Feb-2015 16:01

itxtme:
Interestingly if you sell a house in Australia the board must be done to protect all power plug outlets via an RCD. NZ has its head in the sand somewhat.

Thank you, I didn't know that (and only bought our house 8 months ago in Adelaide).

Just went and checked and we have 1 clipsal rcbm210/30 and 2 clipsal rcbm216/30.
Can't believe I never checked before.

Also, there goes my idea of cheap power measurement used in this thread.

I'd put money on it being my A/C tho.

OT Edit: something that also surprised me in NZ was the lack of requiring rental properties to have smoke alarms. We rented this place before we bought it. It has 4, one is hard-wired. Every house, rental or not, must have smoke alarms by law.

richms

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#1238935 14-Feb-2015 16:02

Last I read up RCD was not mandatory on caravan outlets. That is why campgrounds make people by those absurdly expensive leads with a 16A ceeform plug and in line rcd if they want to use a powered tent site.

I will probably be getting a couple of caravan plugs installed soon to power up a "temporary" building so will see if that is still the case.

Richard rich.ms

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LennonNZ

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#1238937 14-Feb-2015 16:06

Here is a picture of a newish (2 year old) power board (mine)

As you can see RCD's per 3 circuit breakers and the Red Power lead put in a very nice place to place clip on power monitoring on it if needed and the smart meter above.

I wish all power boards where as nice (and labelled)

gzt

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#1239005 14-Feb-2015 18:00

itxtme: That article a few weeks back from the guy who cut the power to the caravan and died is a good example of where an RCD at the box would have stopped a death from occurring. Any dodgey appliances, accidental cord cutting (like when installing insulation in a roof) will trip an RCD,

My understanding is an RCD will not always prevent death in all circumstances. It is just far better than alternatives.

itxtme

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#1239235 15-Feb-2015 09:12

I am sure you are right GZT. Just mentioned it because I know how proactive Timmy is with his house, and it really surprised me when my electrician mentioned it and I did the research on us vs most other 1st world countries! Before that I knew very little about RCD's.

Niel

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#1239470 15-Feb-2015 17:29

In South Africa we call it an earth leakage switch, and my parent's house that was built around 1972 had it as standard. When we came to NZ 14 years ago I could not believe how many houses did not have it. Instead in NZ we just sold plastic covers so that little kids can't put knives into power sockets?

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mclean

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#1240211 16-Feb-2015 17:08

Going back to the OP, you can get a very close estimate of power usage by using a spreadsheet. Everything in the house should have the running current or wattage marked on it. The only tricky one may be the aircon, for which you may need the manufacturer's data, but most have a reasonably reliable running current marked on them.

Then to get the energy consumed apply an hours use/diversity to each load and fiddle with the numbers until it matches your average power bill. It's a lot easier (and probably more sensible) than trying to tong each circuit while the loads are going on an off.

timmmay

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#1240217 16-Feb-2015 17:18

mclean: Going back to the OP, you can get a very close estimate of power usage by using a spreadsheet. Everything in the house should have the running current or wattage marked on it. The only tricky one may be the aircon, for which you may need the manufacturer's data, but most have a reasonably reliable running current marked on them.

Then to get the energy consumed apply an hours use/diversity to each load and fiddle with the numbers until it matches your average power bill. It's a lot easier (and probably more sensible) than trying to tong each circuit while the loads are going on an off.

Probably not accurate enough. I have no idea how much hot water uses in comparison with underfloor heating, and it changes each day according to ambient temperature.

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