Electrics for new garage

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SATTV

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#2421863 16-Feb-2020 16:55

RunningMan:

SATTV:[snip]( I would be running 6mm cable to allow for electric car charging in the future )

I would think that 6mm would be minimum if planning for an EV circuit. Your sparky should be able to advise though, given the cable length etc.

My stovetop has 6mm cable and draws 32A so should be fine, realistically you dont need to charge a car from a 32A socket, a 10A is fine, takes longer I know, most prople would plug their car in when they get home and unplug when going to work. Having 32A allows you to have two cars, a couple of e bikes, beer fridge, Chest freezer and a couple of servers running without an issue.

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Tracer

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#2421875 16-Feb-2020 17:32

richms:

I'm sticking with fluros since they seem to have been flicker free since the demise of magnetic ballasts in the 90's, If I find some retrofit tubes that dont suck I can always remove the ballast and connect the power to the right end and put them in.

Even in saying that, the old mag ballast ones in the garage are noway near as annoying as the LED ones I got for over the workbench, the LED ones go totally out for part of the AC cycle so any strobing on tools is way worse, and video is impossible under them unless I have the shutter set so long that every frame looks like a blurry mess, and use a cinematic 25FPS to match the powerline.

Stroboscopic effect with flouros can be dangerous for machines rotating at a harmonic of 50 Hz as you note. You can get flicker-free LEDs... just the power supplies in the cheap ones are usually junk. See https://www.youtube.com/watch?v=BTq33MiVAsI if you really want to know what's going on.

SATTV:

RunningMan:

I would think that 6mm would be minimum if planning for an EV circuit. Your sparky should be able to advise though, given the cable length etc.

My stovetop has 6mm cable and draws 32A so should be fine, realistically you dont need to charge a car from a 32A socket, a 10A is fine, takes longer I know, most prople would plug their car in when they get home and unplug when going to work. Having 32A allows you to have two cars, a couple of e bikes, beer fridge, Chest freezer and a couple of servers running without an issue.

John

Voltage drop can become an issue with longer runs, which might push you up to 10mm2, and it'd be worth checking the price for 16mm2 as sometimes it can be very cheap (very common house mains size).

richms

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#2421887 16-Feb-2020 18:19

Tracer:

Stroboscopic effect with flouros can be dangerous for machines rotating at a harmonic of 50 Hz as you note. You can get flicker-free LEDs... just the power supplies in the cheap ones are usually junk. See https://www.youtube.com/watch?v=BTq33MiVAsI if you really want to know what's going on.

Its not only that, the whole room looks like its vibrating when lit with those. Ok for being under short term but doing any work which requires concentration - forget it. Like a wall of CRTs flickering away at you.

They love the flickery power supplies because they can leave out capacitors, which mean their power factor is better, which means that they qualify for subsidies in countries that do that sort of BS. They don't care about the people that have to be under the lighting, they just care that they can say "look, we are subsidizing green eco lighting" and then everyone goes oooooooh your a good government.

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richms

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#2421889 16-Feb-2020 18:28

SATTV:

RunningMan:

SATTV:[snip]( I would be running 6mm cable to allow for electric car charging in the future )

I would think that 6mm would be minimum if planning for an EV circuit. Your sparky should be able to advise though, given the cable length etc.

My stovetop has 6mm cable and draws 32A so should be fine, realistically you dont need to charge a car from a 32A socket, a 10A is fine, takes longer I know, most prople would plug their car in when they get home and unplug when going to work. Having 32A allows you to have two cars, a couple of e bikes, beer fridge, Chest freezer and a couple of servers running without an issue.

John

Remember that you are the one paying for that voltage drop downstream of the power meter, so it matters. If you are going to be pulling many kWh thru it then the 2-3% loss will add up. I saw the figures on the payback for using 6mm on a hot water circuit vs 2.5 and that stacked up over a few years of normal usage.

Richard rich.ms

RunningMan

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#2421892 16-Feb-2020 18:40

SATTV:

My stovetop has 6mm cable and draws 32A so should be fine, realistically you dont need to charge a car from a 32A socket, a 10A is fine, takes longer I know, most prople would plug their car in when they get home and unplug when going to work. Having 32A allows you to have two cars, a couple of e bikes, beer fridge, Chest freezer and a couple of servers running without an issue.

John

Any decent EVSE will need 32 amp continuous. Any car plugged into a standard 10 amp outlet will normally be limited to 8 amps to reduce the chance of the outlet overheating. That's painfully slow to charge anything but a lower capacity battery that isn't completely flat. It may well be fine for overnight for a LEAF, but now is the time to be looking at future proofing. Newer EV's are getting higher and higher capacity batteries, and some will take 24-48 hours at that rate. If you've got a dedicated 32 amp circuit for vehicle charging, then the feed to the building needs to be able to cope with that continuous load, as well as any other load from lighting or other power demands. Cable is cheap compared to the difficulty in having to upspec it later when it doesn't meet a need. The voltage drop across the length of the cable under maximum load also needs to be taken into account, so I would strongly suggest the sparky does the calculations to work out what cable is needed. 6mm may not be enough.

nickb800

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#2421901 16-Feb-2020 19:12

Garages are easy to rewire internally, so the most important thing now is to get the power feed from the house right - 32 amps is a good number to aim for EV charging, sparky will advice if 6mm can do it or if you need something bigger - probably 16mm (very common cable and can often be installed without conduit).

Might as well chuck some direct bury cat5e/6 in the trench above power. You might find the Faraday cage effect of the metal wall cladding kills any wifi signal from the house - so you might need a wifi access point out there.

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Talkiet

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#2421943 16-Feb-2020 19:54

I literally had the 9x6 high ceiling shed at my new place wired up just last week. It's not my primary garage so I didn't get a big circuit there for future EV charging. I am also still wincing quite a lot from the purchase price and a few unexpected costs in moving, so I took an economical but still hopefully reasonable approach.

It's on a single 32A circuit from the house and I have

- 4 x double 10A sockets around 2 of the 4 walls

- 1 x 15A socket for a welder or hoist

- Single switched lighting circuit with 3 10A sockets on the ceiling so I can add warehouse LED floodlights as necessary (I have 2 up already and a 3rd on the way - 150Watt Aliexpress specials - hugely bright!)

- Cat6 from inside mandoor to sectional door opener on ceiling

- In order to be legal to use an existing wall penetration (for the power cable from the main switchboard) I ran fibre to the shed.

The electrician had to dig a 2.5M trench, 600mm deep and laid 2 conduits in it.

There is a submain and RCD installed.

For context, the whole job cost $2050 including CoC. I was happy with everything.

Cheers - N

Please note all comments are from my own brain and don't necessarily represent the position or opinions of my employer, previous employers, colleagues, friends or pets.

insane

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#2422002 16-Feb-2020 23:35

Any reason why you'd go with LED batterns over large LED panels?

https://evolve-lighting.co.nz/products/sky-panel

There's a kiwi carpenter, Scott Brown on YouTube who uses panel lights in his storage shed, and his Canon 80d he records with picks up no flickering.

raytaylor

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#2422017 17-Feb-2020 00:05

Wheelbarrow01:

I don't have (and don't believe I will ever have) anything in the garage which requires an internet connection, so I am not going to reticulate Cat 6 out there.

At least put a couple of cat6 cables in a duct when you install the power.
- Internet connected beer fridge/freezer
- Youtube repair videos
- Internet connected garage door opener
- Alarm sensors etc.

You dont have to do much - just chuck a pair of cables in a duct so they are there if you or a future owner needs them.

Also think of an electric car charger when specifying your cable thickness.

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kotuku4

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#2423344 18-Feb-2020 16:49

Wheelbarrow01:

it will cost a small fortune for power and drainage ....the old garage has an ineffectual soak pit for stormwater which cannot be reused, so I am required to connect the new garage to my house stormwater - with the closest accessible outlet being (you guessed it) at the very front of my house.

Are you required to connect stormwater to council drainage? Soakage does not sound great in your case. However there may be options, such as using tanks as storage to attenuate runoff, use a small restricted outlet to get water away from garage to suitable area to irrigate, rain garden, or shallow soakage. Or in ground storage//soakage eg cirtex rainsmart.

Wheelbarrow01

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#2423565 19-Feb-2020 01:48

kotuku4:

Wheelbarrow01:

it will cost a small fortune for power and drainage ....the old garage has an ineffectual soak pit for stormwater which cannot be reused, so I am required to connect the new garage to my house stormwater - with the closest accessible outlet being (you guessed it) at the very front of my house.

Are you required to connect stormwater to council drainage? Soakage does not sound great in your case. However there may be options, such as using tanks as storage to attenuate runoff, use a small restricted outlet to get water away from garage to suitable area to irrigate, rain garden, or shallow soakage. Or in ground storage//soakage eg cirtex rainsmart.

Yes I should have been more clear - I am required to connect the new garage to the house stormwater drain. The old garage was built circa 50-60 years ago when soak pits were presumably acceptable in urban settings.

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