2 houses being combined into 1 - electrical rewiring options

[stadamack]

Hi all,

2 adjacent terraced houses are being joined into one. The electricity company meter cabinet is towards the front of each house and the consumer units are over the rear door in both instances. The heating system is oil and there is no storage electric or heat pumps in either unit, therefore, it is likely both houses are 12kVA supplies with 16mm2 mains tails. The houses were built in 2002.

The final house would have only 1 no. cooker with oil heating and so a 12kVa supply should suffice for the final two units combined,

It is proposed that 1 of the electricity meters would be disconnected and the associated consumer unit would be connected with a new 16 mm2 SWA to be installed to the other consumer unit. This would serve to minimize the amount of rewiring required,

Question:
1. do electricity utilities have particular requirements for supplies to previously separated houses?
2. Any obvious oversights in the above proposal?

Thank you,

 

[Mbrooke]

@Itsmoked: Welcome

BTW, if using wire tails, you just have to remove the pair from the breaker you are changing. But when you see people using 2.5mm2 for busbar, I guess the solid one included with the panel is a good thing lol.

 

[cranky108]

Good discussion. However, some of our customers don't have 120/240V service, they have 120/208V service, which can make motors draw more current when connected phase to phase.

We only have a few of these near downtown.

 

[Mbrooke]

True, though never heard it cause problems other then a few AC units that needed a hard start. Technically, reconfigurable 480 volt motors would work on 416 volts

If anyone is interested, here is the old fuse version of a consumer unit:

https://www.youtube.com/watch?v=0L0p5Rk7hZU

 

[waross]

I stand corrected Mbrooke. You have probably guessed that it has been a long time since I have hooked up a water heater.
A lot has changed. The increase in the allowable ampacity of from 15 Amps to 20 Amps @ 75 degrees and to 25 Amps @ 90 degreesis a big change.
Breakers rated for continuous use at 100% loading used to be premium priced. It's sometimes easier to up-size the breaker rather than find one rated for continuous use at 100%.
I apologize for my mistake.
2012 was the 22 edition and 2015 was the 23 edition, however the 2015 edition has section headings which state words to the effect that
"This information is current as of 2014" You may be easily mislead.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Mbrooke]

No worries and no need to apologize- things change so fast it impossible to keep track. I can assure you that there is way more I personally have no caught up on.


Regarding the change its a bit ironic- the CEC did it to harmonize with the NEC tables which at the time #14 was listed at 20amps for 60*C and 75*C. Soon after the NEC changed its values to 15amps at 60*C. Doing research it appears the actual ampacity of #14 is around 18amps at 60*C, so I could see it being nothing more then rounding in that regard. But in any case its trivial, modern THHN used in NMD-90 and NM-B is many times over more resistant to heat then the old TW and rubber coated stuff.