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Evening gents,

i was wondering if anyone had any links or if someone could explain in leymans terms Any information about floating earths in generators, never had any experience in them and hate not knowing things when they could come in handy one day!! Doesn't have to be any specific just a quick over view which I could possible learn something from.

also I've heard stories about when overseas (afghan army camp) some equipment is run by both USA and our own 230v how is this stepped up or stepped down from the same source? Sorry if im being vague

thanks in advance for any replies

tom
 
In our place the generator earth is connected to its own earth mat it's separate from the buildings main earth I think something along the lines of if there's an earth fault on the building and the electric trips it won't take the gunny out there for the gunny can run essential services in the building ie comms rooms etc

- - - Updated - - -

Gunny I ment the genny
 
A floating earth is only used on small site generators. The centre point of the single phase winding is connected to the chassis. This gives an output that must use two pole protection.
 
A floating earth is only used on small site generators. The centre point of the single phase winding is connected to the chassis. This gives an output that must use two pole protection.

I think it's worth adding that this type of generator is completely unsuitable for backup power for any kind of installation. These generators are for running small loads such as power tools and the odd temporary appliance such a portable pump or compressor.
 
Evening gents,

i was wondering if anyone had any links or if someone could explain in leymans terms Any information about floating earths in generators, never had any experience in them and hate not knowing things when they could come in handy one day!! Doesn't have to be any specific just a quick over view which I could possible learn something from.

also I've heard stories about when overseas (afghan army camp) some equipment is run by both USA and our own 230v how is this stepped up or stepped down from the same source? Sorry if im being vague

thanks in advance for any replies

tom

Tony addressed the floating Earth, but with regards the services at FOB's in Af these are run from separate gen Sets because we use 230V single phase/400V Polyphase 50Hz services and the Silly Planks use 120V single Phase, 240V dual Phase 60Hz services. It is possible to use a 120V Tx with a inverter installed for frequency change, but these are only economic at small powers, once you get above about 5kVA the costs is ridiculous and it's cheaper to have two gen sets.
 
Just to give you a laugh, a now dead friend (old age) had the problem of 50/60Hz.

He altered the governor on the generator to give 55Hz. Time went quick for the British, a little slow for the Americans!

BTW we run at 50Hz?

Have a look at:

http://www.dynamicdemand.co.uk/grid.htm

Lets all do a joint power down of our CU's on mass and see if we can get the Gen to trip ...... i suggest during Big Brother an ideal time ;)
 
Anyone fancy a cup of tea at 20:36? They'll be relaxing after the 20:30 advert break!
 
Tony addressed the floating Earth, but with regards the services at FOB's in Af these are run from separate gen Sets because we use 230V single phase/400V Polyphase 50Hz services and the Silly Planks use 120V single Phase, 240V dual Phase 60Hz services. It is possible to use a 120V Tx with a inverter installed for frequency change, but these are only economic at small powers, once you get above about 5kVA the costs is ridiculous and it's cheaper to have two gen sets.

Brilliant that's what I was trying to find, 95% sure I'm got a start on the troop withdrawal contract so need to have some reading material to look up
Many thanks
 
Tommy this might come in handy, hope the attachment comes out ok!

What this ECA GN does not tell you, is that these small single phase floating earth gen-sets should not be used on household appliances, fine for small resistive loads like kettles and small heaters and the like but not so good with any form of electronic or electronic controlled appliances. Virtually none of these small gensets will incorporate a stabilized regulated voltage output, they will be totally dependant on load vs speed for voltage output!!

Look at the instructions/manuals of any of these small gensets and you will find somewhere in the literature, exactly what i'm saying, and that the manufacturer will not be held responsible for any loss or damage where such appliances have been connected to the gen-set...
 
Brilliant that's what I was trying to find, 95% sure I'm got a start on the troop withdrawal contract so need to have some reading material to look up
Many thanks

As if our troops don't have enough to worry about!

Some half baked loonie is heading their way to add to the problems. With luck you may save a life.









With any luck you'll take the bullet.
 
Tony,
You really are a poor excuse for a human and a waste of skin, why don't you come out here and do something? A person of your high standing will be listened to and all the electrical problems will be put right overnight!
Instead of criticizing why not help out?

Companys don't care if your qualified they get paid by the governments for the number of boots on the ground, so getting someone out here who is doing some research is good for the troops. No-one know's everything (except you). I've had a soup chef work for me as an electrician! Did the company care he was Sh.t .... no they got paid and the money wheel kept on spinning.

I don't think you'd last a week out here mainly because you'd be filled in on the first day for mouthing off with your holy than though attitude and for wetting yourself after the first ground/rocket attack/round up.

Day one if you got that far... I'd send you to do the perimeter lighting in an orange boiler suit with a high vis vest on (All in the name of safety of course, I'd never send you out to get shot) to see if you could sort the problems out.
Don't worry about security I have couple of Afghan Army types look after you especially on a Thursday night.... that will become your favourite night.

In short Tony go and choke on..... 'a male chicken' .


Tommy.dale PM me when you get a start date and FOB.... and good luck
 
So it’s acceptable to send someone with no idea of what they are doing in to a situation where peoples lives could depend on them.

RE, what’s that? Can’t be Real Engineer, if it did you would recognise a chancer!

Where’s you’re advice on the power systems he’ll encounter? Surprisingly lacking given you’re vast knowledge of Afghanistan and the requirements of the military.

In Tommy’s first post he asked a general question not unlike many others. The only hint is this, nothing definite.

“also I've heard stories about when overseas (afghan army camp) some equipment is run by both USA and our own 230v how is this stepped up or stepped down from the same source? Sorry if im being vague”

Vague doesn’t come in to it. Does it say he’s going overseas, no it doesn’t!

Sorry I can only take things as I read them. I gave the best advice I could based on FACT.
 
Tony,
You really are a poor excuse for a human and a waste of skin, why don't you come out here and do something? A person of your high standing will be listened to and all the electrical problems will be put right overnight!
Instead of criticizing why not help out?

Companys don't care if your qualified they get paid by the governments for the number of boots on the ground, so getting someone out here who is doing some research is good for the troops. No-one know's everything (except you). I've had a soup chef work for me as an electrician! Did the company care he was Sh.t .... no they got paid and the money wheel kept on spinning.

I don't think you'd last a week out here mainly because you'd be filled in on the first day for mouthing off with your holy than though attitude and for wetting yourself after the first ground/rocket attack/round up.

Day one if you got that far... I'd send you to do the perimeter lighting in an orange boiler suit with a high vis vest on (All in the name of safety of course, I'd never send you out to get shot) to see if you could sort the problems out.
Don't worry about security I have couple of Afghan Army types look after you especially on a Thursday night.... that will become your favourite night.

In short Tony go and choke on..... 'a male chicken' .


Tommy.dale PM me when you get a start date and FOB.... and good luck
Oye...
you go up against him.....you go up against me...
Understand?..
 
The type of power systems you will encounter in theatrewill be safe (ish) to absolute death traps and because no-one has died theywill be kept !
4 wire (TN-C) is banned by Task Force Power but you willcome across it. Same as TT not allowed but its here.
4&5 (TN-C-S) wire will be the main type but they willbe riddle with N-E bonds fitted randomly in MDP's (Main Distribution Panel's),SDP's (Sub-...) and CDP's. They system will also revert between 4-5-5-4-5-4-...etc producing 'Objectionable' current in EGC (Equipment Grounding Conductors)/CPC's, conduit (pipe). watch out for N bars screwed to the panel with noinsulation (back to a 4wire) and bolted to a metal skinned building.
All new electrical Systems are to be 5wire (TN-S) TFPowerdirective as they are easier to understand and follow.
Transfer switches will be 3pole or 4pole. 3pole T/S areto have only one genny N-E bonded. 4pole, both gennys are to be N-E bonded.
Cable on nearly every distribution system will have beenwhat was around at the time so you'll have 4c rubber in the ground no ductingand about 4-6inch below the hard core. But mostly it will be surface laid evenacross roads with some sand bags on top (if you’re lucky).
Most MCB's will be massively over rated e.g. found a3500A feeding a 120mm 4c SWA other end was a 500A though, so that was better!!!!
Lots of cables will have been given a haircut to get themto fit into breakers, bars, lugs etc
SWA will have been cut with only 10-30% captured andrammed into the earth bar. Split bolt repair is approved.
Earth spike are routinely cut off so a 10foot rod mayonly be 4foot and that’s all a 750KVA genny will have
A cable will start of as a 5c SWA and pop out the groundas a 4c SOOW, so be warned.
120/240V MCB's means they can have 240 3phase in them butcan't be fitted to 230/400v boards but they are.
Boards will be rated to 240V/277V but will have 380-440Vin them.
Ip rating is NEMA. kit should be IP54 min (3R) but isn't.Usual thing is build a cupboard round it.
Guards will be missing in most boards and homemade panelswith live Buss bars open to touch are common.
Gland plates are an optional extra for SWA but as mostSWA isn't glanded off there is no need for them!! So just let the weight of thecable hang from the terminal of the breaker and as there is no gland platethere will be plenty of air to stop the MCB overheating.
Air temp is 50degrees C ground temp is 35 if you botherto do any calc's.
Systems may have been put in for 60Hz 120v kit and todaysgenny is 50Hz220-250v so watch out the amount of kit that gets fried as thewrong voltage is coming out of the socket.
Never come across a frequency converter loads of trannysthough from 50w plug in to 'massive'!

The above are all facts given tongue in cheek.

If you’re here closing down camps buy a solar shower asthere will be no grey water recovery toward the end and LSS units will havegone too. So get use to the idea of dropping a 'Richard the 3rd' in to a bag.

Tony. I never said it was acceptable its what happensthough.
I never said or implied I have a vast knowledge ofanything. But I hope the above helps out someone.

RE = Royal Engineers, so you were part right it doesn'tstand for Real Engineers, but we are :) in every way and every day.

Your right he doesn’t say he is coming out here but I'dsay it was implied as "95% sure I'm got a start on the troop withdrawalcontract" and asking about electrical in Afghanistan. I may be wrongthough on that.

Glennspark, What? You the sites Internetshire enforcer?

 

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