Floating earth - generators

[tommy.dale]

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

 

[Farmelectrics]

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

 

[Knobhead]

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.

 

[GLENNSPARK]

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.

up to about 7 KVA i think Tony...

 

[Marvo]

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.

 

[tommy.dale]

Thanks guys

 

[Outspoken]

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.

 

[Thefailsafe2012]

Sorry, was going to post a link but fudged it!

 

[Thefailsafe2012]

Tommy this might come in handy, hope the attachment comes out ok!

 

[Knobhead]

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

 

[Darkwood]

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

 

[Knobhead]

Anyone fancy a cup of tea at 20:36? They'll be relaxing after the 20:30 advert break!

 

[tommy.dale]

Tommy this might come in handy, hope the attachment comes out ok!

Very helpful thanks a lot mate

 

[tommy.dale]

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

 

[Engineer54]

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...

 

[Knobhead]

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.

 

[old_sparky_RE]

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

 

[Knobhead]

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.

 

[GLENNSPARK]

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?..

 

[old_sparky_RE]

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?

 

[GLENNSPARK]

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?

no.....
just a fella.....
who got a bit browned off when you gave a very respected member in here a load of verbal diarrhea

 

[Hants-Spark]

no.....
just a fella.....
who got a bit browned off when you gave a very respected member in here a load of verbal diarrhea

Loyalty is a good trait and one I admire, but if someone wished upon another that "With any luck you'll take the bullet" I'd be questioning my judgment. I for one say good luck to all our troops in the battle zones and stay safe, keep up the good work and come home soon.

 

[Knobhead]

OK the bullet was OTT.

From what you say of this ramshackle system it beats me why it isn’t just disabled and abandoned. With the amount of money that’s been wasted over there it would be a drop in the ocean.

I’m sure you could come up with a fun way of disabling the generators.

 

[old_sparky_RE]

Are you Mad Tony??? That would mean the money wheel would stop spinning and these company's wouldn't get there $4000000000 (yes thats 9 zero's) honey pot!!!! And where you going to put 100000+ troops while its all sorted?

We just keep smiling and repairing trying to make do with the kit that gets delivered*. "We're here to add Band-aids' nothing more" ... "keep it going till the place closes and hope no one get hurt".

*Order 6Amp RCBO type 'B' and get a 40A MCB type 'D'. Cheaper kit from the UAE you see
Order 120mm 4C SWA get 4C rubber (SooW).... whats wrong its got 4 bits of wire in it?!
Order 20mm PVC conduit get 200mm Drain pipe, with 15000 20mm saddles (ordered 150 (3boxes))
Order E/M light for 230V 50Hz get 120v 60Hz or.... 277v 60Hz (frequency is still out)

This morning found this 4C SWA with SWA cut off below board, neutral then linked to Earth bar with a metal bar (looks like a dinner knife handle) with the EC wrapped round that leading to a cut down ground rod !!

Get caught sabotaging kit you'll end up in a military nick in the states for a couple of years playing hide the sausage if your lucky, unlucky you'll be playing hide the coke can sized sausage for a couple of years mg_smile: !!

 

[Knobhead]

OK does this make sense, as each camp is abandoned destroy the machines and infrastructure. (From you’re description, is there anything worth saving?) No personnel need stay back.

The troops and ancillary personnel will have to be dealt with somehow no matter what.

As you say, there’s money to be made. The trouble is, it’s tax payers money.

The main thing I will disagree with you is you’re statement “boots on the ground”, inexperienced personnel are so dangerous!

 

[old_sparky_RE]

Some Genny's will be kept and moved about, trouble is Afg is landlocked, so no way of getting the kit out.

Pakistan open's and close's the boarder all the time so kit struggles to get in/out, so whats not expensive/easy to move will be destroyed. Test meters which arn't used in the States are driven over, seen 20+ Flukes crushed under a truck wheel in the name of accountability and to stop them falling into the Enemy's hands !!! What Terry wants with a Fluke? I don't know, I'd be more scared of Terry running at me with an AK then a Fluke on Insulation Resistance test !!

Some places will be destroyed totally (nothing left) and the area ploughed to even get the power cables up, some will have brick building left behind for Afg Army etc to use and some places are being specially built for the Afg (Garrison sized) filled with everything you could ever dream of.

What else you going to do with the money Tony... Health, education etc? Best keep throwing another bundle on the fire to keep me off the streets of the UK.

Inexperienced people are a danger but what would you prefer: an inexperienced electrician working on the electrics or (I KID YOU NOT) a soup chef from a hotel in Dubai playing with it!!? They're paid the same and the company skims the top off. The wheel keeps on rolling.

 

[Knobhead]

Crazy, crazy world.

We had plants demolished. I asked can I get --- out first? No it’s all going, it’s all salvage for the demolition company.
Two weeks later I’m putting an order in for something that’s just driven past me on the back of a scrap wagon.

Correction to the above, stupid, stupid world! (Corrected for accountancy).