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Thread: standby generators

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    standby generators

    how many people out there have generators installed and are not sure if they are in fact connected correctly according to the sans regulations....well i am sure there are many...

    this is the reason like witnessing crime i prefer not to get involved...i get called out to a site were a homeower who has a 2 year old child want to know if the generator installation is safe...so i go to site have a look and find these problems
    no earth leakage on the plug circuits connected to the generator
    no mechanical interlock
    relays underated for the size breaker protecting the circuit
    no barrier between the generator supply and the normal supply
    generator is installed below the kitchen window outside
    panels are not weatherproof mountwed outside
    no earth spike...and more

    and these were just a few of the items i notice while doing a visual inspection...but on hearing the electrical contractor had not yet issued the COC i decided to rather walk away from the job until the electrical contractor has issued the COC...because i have learnt from experience no matter how many YEARS it takes the electrical contractor to issue the COC the job is not finished ...my main concern was the fact the plugs were not connected to earth leakage unit...so i informed the customer of this and left...i then got a call from the husband who seemed concerned...so i advised him of the situation and said there was nothing he could do until the COC was issued and that i did not want to get involved until it was done...10 minutes later i get a call from the electrical contractor wanting to know who the hell i thought i was going onto his site and telling the customer that his installation was unsafe...well as far as i am concerned not having plugs on earth leakage with a 2 year old crawling around is like leaving a loaded firearm lying around with teenagers...anyway it comes out that he is not finished with the installation yet... as i expected he would say...apparently he explained the situation to the owner that there is no stock of the earth leakage units which he required...so in the meantime if the 2 year old is electricuted who is going to be at fault the supplier of the earth leagage unit? the electrical contractor? the parents?

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    be extremely careful with generators...make sure your installation is done correctly...if a generator is not installed correctly not only can it electrucute you to death no matter how small the unit is...the fumes can kill you...an example of a bad installation...dont put the generator in the garage and close the door while it is running...sound stupid...well people are doing this...suicide cords are a reality plug top to plug top...in the generator and straight into the wall socket...i know the fella at makro springfield is advising people of this quick fix...it makes the entire grid unsafe not only for the homeower but also us suckers who have to work on the lines...feed back into the system.

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    Site Caretaker Dave A's Avatar
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    Murdock, I have to agree with you on the earth leakage protection issue in particular. It is definitely worth stressing. Having a generator supply without earth leakage protection is like leaving a loaded gun around the house.

    I was thinking through the hazards of generators a while back, and they have got to be one of the most dangerous machines around.
    • You have the flamable hazard of the fuel.
    • You have the burn hazard of the hot exhaust.
    • You have the toxic gases hazard of the exhaust fumes.
    • You have the electrocution hazard of the electrical supply.

    Coming from the pest control industry, I used to think that what we work with is dangerous. With a few exceptions, I believe electrical generators are far more hazardous.
    The trouble with opportunity is it normally comes dressed up as work.

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    just me duncan drennan's Avatar
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    Can we look at a particular case quickly (my case that is...):

    If the power goes out (which it generally does not), I unplug my UPS from the house plugs, start the generator and plug the UPS into the generator (which is running happily in outside in a well ventilated area). There are no earth connections.

    What else do I need to make this set up safe?
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    so what you are telling us is that everything you plug in is double insulated so there is no chance of any exposed metal parts becoming alive when the is afault or you have a safety transformer...like a shaver unit in a bathroom.

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    just me duncan drennan's Avatar
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    Well, no, I can't say that it is. Most of it is, but the UPS for one has a metal case, which would mean that it is not double insulated. Obviously any PC (I normally use a laptop though) isn't either.

    I can see how this presents some kind of a problem. Any fault to the casing would then expose live to the user.

    But, is it a danger? In this case the generator is also effectively floating (compared to earth). Even if the user is earthed, there is no closed loop for the current to flow in - or am I totally wrong?
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    Site Caretaker Dave A's Avatar
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    I think if you're serious about electrical safety in a stand-alone generator situation:
    • Earth the generator properly with an earth spike or to a metal water pipe that goes into the ground.
    • Bridge the earth and neutral.
    • Have an earth leakage unit in after the bridge.
    The trouble with opportunity is it normally comes dressed up as work.

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    just me duncan drennan's Avatar
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    Once that is in place, what is a safe (but effective) method to test whether the earth leakage is working properly?
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    an earth spike is a regulation you have to install an earth spike at the generator.
    you have to connect the neutral and earth at the generator but no else in the installation.
    and use an earth leakage tester they are not expensive...in fact i am considerering buying all my customers an earth leakage tester so they can test a plug with it before they call me... because it has indicator lights on it...for reverse polarity...no neutral...no earth...etc...and if you have small children it is got practise just to trip the e/l unit evey now and again just to makes sure it is working within the spec around 20-25 mA

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    Moderator IanF's Avatar
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    Quote Originally Posted by murdock View Post
    a
    and use an earth leakage tester they are not expensive...in fact i am considerering buying all my customers an earth leakage tester
    Murdock
    Can you give us name and specs of the tester it sounds like a good buy, also what is the price range this is for me who just knows electricity is dangerous.
    Only stress when you can change the outcome!

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