Author Topic: Is my new rooftop A/C unit bad? (tripped breaker)  (Read 12330 times)

Offline belfert

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #30 on: July 15, 2013, 04:55:27 AM »
American junction boxes don't have terminal strips in them, at least I have never seen one with a terminal strip.  I think wiring would probably be easier than wire nuts.

Doesn't the UK use very high amperage circuits and then each item has its own fuse or breaker?  Here in the USA we use smaller circuits and depend on the breakers at the main box to trip if a circuit is overloaded.
Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN

Offline luvrbus

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #31 on: July 15, 2013, 05:11:17 AM »
Isn't most if not all of the power 3 phase in the UK it was in Germany
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Offline bevans6

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #32 on: July 15, 2013, 05:24:24 AM »
It's 3 phase in the same way that our power is 3 phase in North America, the distribution grid is 3 phase.  Power distributed in residential type buildings is single phase (basically derived from one leg of the 3 phase, exactly the same as here), just at 220v instead of 120v.  I don't know if high power appliances get split-phase 440 the way we get split phase 240.  I have a mill motor that came in my Harrison mill that came from England that is 440 volt 3 phase, they ran it here on a step down transformer.  Canadian industrial 3 phase is normally delivered at 600 volts, but you can get 208 volts as a special sometimes.  The in-building power plant reduces it for normal single phase plugs and the machines mostly run on the 600 volts.  When I got my Bridgeport it had a 600 volt 3 phase motor that I had rewound for 208 volts and I use a converter to start it, then it runs on split phase.

Brian
« Last Edit: July 15, 2013, 05:27:15 AM by bevans6 »
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Offline Jeremy

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #33 on: July 15, 2013, 05:30:51 AM »
Isn't most if not all of the power 3 phase in the UK it was in Germany

The power supply to the street is 440v three-phase, which is what industrial equipment used by businesses runs on. But houses only get half that - literally the houses on one side of the street take one leg of the supply, and those on the other side take the other leg - or so I understand it


American junction boxes don't have terminal strips in them, at least I have never seen one with a terminal strip.  I think wiring would probably be easier than wire nuts.

Doesn't the UK use very high amperage circuits and then each item has its own fuse or breaker?  Here in the USA we use smaller circuits and depend on the breakers at the main box to trip if a circuit is overloaded.

I've no idea how amperages compare; here is a typical UK fuse box (or 'consumer unit', as they are called):



10-way, 16-module high integrity, insulated consumer unit with a smooth profile and flexible busbar. BS EN 60439-3.

    100A Main Switch
    2 x 63A RCDs
    10 x MCBs (3 x 6A
    2 X 16A
    4 x 32A
    1 x 40A)
    10-Way (5+7+7 Way)

The two RCD (earth leakage trips) will be for the kitchen (and any outside supply) and the bathroom (ie. electric shower), because the law says you have to have RCDs wherever there is water in the vicinity to an electrical supply.

The two 16A breakers will be the lighting circuits (upstairs and downstairs), and the four 32A breakers will be for various ring mains (ie, outlet socket circuits). Not sure what the 40A breaker will be for - probably an immersion water heater supply.

http://www.screwfix.com/p/bg-10-way-high-integrity-populated-insulated-consumer-unit-dual-63a-rcd/72088#


My bus incidentally has one of these (this exact model as it happens) - A three circuit consumer unit intended for sheds/garages/outbuildings:



 IP55. 5-module plastic, garage kit enclosure with a neutral cable and flexible busbar.

    1 x 40A 30mA RCD
    2 x MCBs (1 x 6A
    1 x 32A)

http://www.screwfix.com/p/bg-garage-kit-enclosure-5-module-ip55-40a-rcd-dual-6a-32a-mcb/68849


Jeremy



Edit:- Brian was typing at the same time I was - what he says is correct. I've never heard of a house using the 440v supply for any 'domestic' equipment, but I'm sure it's doable in theory; certainly a friend of mine had a three-phase power supply installed at his home-based business to power the industrial sewing machines he uses. I also know that in certain fashionable circles (ie., mega-buck homes in London) it's de-rigur to have full restaurant-spec cookers etc in your home kitchen, which might well need a 3-phase supply
« Last Edit: July 15, 2013, 05:42:47 AM by Jeremy »
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Offline luvrbus

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #34 on: July 15, 2013, 05:47:13 AM »
That's kinda what I thought here it not much of a problem starting and running a 3 phase motor on single phase but AC and refrigeration products are a little different refrigeration compressors that require the 208 3 phase there is no way to start those without a $$$$ converter on single phase and manufactures do not recommend it 

I went through this not long ago when my son bought some commercial refrigerators from the UK
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Offline Len Silva

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #35 on: July 15, 2013, 07:28:14 AM »
My experience with twist connectors (Wirenut is a brand name from Ideal), thousands of them, is to strip the wires about 1-1/2" then twist them tightly with pliers.  Cut off the twisted wires about 1/2" beyond the insulation and install the wirenuts.  They should also be tightened with pliers or a wirenut tool.  Use only name brand products and Ideal is probably the best.

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Offline chessie4905

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #36 on: July 15, 2013, 09:33:54 AM »
Please remove those images of European fuse panels...if our electrical code  book people spot them, we'll all have to switch our panels to the same thing. ;)
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Offline bevans6

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #37 on: July 15, 2013, 10:52:41 AM »
Don't forget that in England a lot of electricity is retro-fit onto (not into) centuries old structure, the electrics run on the outside of the walls and that electrical panel may well be on the transom above a door...  The plumbing is run on the walls outside, that sort of thing.  And all products designed to be visible, look good and be safe.  We hide our stuff inside walls, in basements, etc...  They don't have inside of walls, or basements, sometimes.

Brian
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Offline Scott & Heather

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #38 on: July 16, 2013, 05:05:40 AM »
Wow. So sorry to the OP for the thread drift but this is so interesting. I've been to a lot of countries but never paid much attention to how they do power as long as I had my converter. Fascinating. This matters to me because an older gent with a heart of gold wired our coach for
us but didn't twist the nuts tight enough in a couple of fixtures and the nuts smoked and melted. I replaced them and never had a problem but I'm not waiting for it to happen again.


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Offline belfert

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #39 on: July 16, 2013, 12:08:15 PM »
Back to the original issue:  I think I figured out the issue with the breaker tripping.  The voltage from the generator is dropping too low when the third A/C starts up causing the new Atwood A/C unit to blow the breaker. 

The generator voltage unloaded is around 126 and with three A/C units it is about 112 or 113.  Everyone I have talked to says I can go up to 130 unloaded.  I just replaced the regulator so it should be working fine.
Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN

Offline Lin

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Re: Is my new rooftop A/C unit bad? (tripped breaker)
« Reply #40 on: July 16, 2013, 12:46:25 PM »
My generator voltage readings are similar to yours.  Our frig gets a fault code about AC voltage being to high if the voltage goes above something like 125v.  It can be a real balancing act.
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