Isuzu Trooper Owners Club UK™

Gribble · Posted: Tue Jan 18, 2011 22:33 Post subject: 3 phase wires .

Plese can anybody tell me why (in plant fitters term and no links to wiki ,google , ect - dun me swede in reading that lot ) you get 235v if you measure phase to earth and 440v if you go phase to phase ?

I have a fair grasp of dc systems but this ac is witchcraft , its like early parker crusher wiring !

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super trooper 101 · Posted: Tue Jan 18, 2011 22:50 Post subject:

not to sure but some chap tried to explain it to me once, sine/sin waves were used, as the 3 waves (each one being a phase) crossed over they combined to give the 415volts. they alterenated between the 2 out of the 3, the 3 never crossed together, like i say not sure how. but i dont wonder that sometimes 240volts isnt always such, can be a bit lower 220? some loss is possible maybe? so giving 440volts?

will shut up now before i go on Laughing

markymoan · Posted: Tue Jan 18, 2011 22:54 Post subject:

3x220-240 so 2x=440ish, if a motor is spinning the wrong way then swap any two phases and it changes direction, I agree, its witchcraft Laughing

Just never cross the streams Shocked

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markymoan · Posted: Tue Jan 18, 2011 22:56 Post subject:

PS. 440v will be load free
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super trooper 101 · Posted: Tue Jan 18, 2011 23:05 Post subject:

MikT725 · Posted: Sun Jan 23, 2011 14:50 Post subject:

To put it very simply when one phase is at positive max voltage another is at negative voltage (AC voltage is constantly changing direction) hence you get, if you like, one phase pushing 200V and one phase pulling 200V gives you 400V siiiiimples.
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1999 3.1td SWB Trooper. RIP
2004 3.1td LWB

Gribble · Posted: Sun Jan 23, 2011 18:43 Post subject:

Ok thats that bit done , now whats meant by 'High leg delta ' ?

markymoan · Posted: Sun Jan 23, 2011 19:27 Post subject:

Without getting technical A high leg delta (also known as wild-leg or red-leg delta) is a type of electrical service connection often found in older three-phase electric power shop or industrial installations. It is used where both lighting and three-phase motor loads are fed from the same distribution system.
Technical from wiki
http://en.wikipedia.org/wiki/High_leg_delta
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markymoan · Posted: Sun Jan 23, 2011 19:32 Post subject:

I'm no expert but we used to borrow a phase for lights in the workshed.
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scj103 · Posted: Sun Jan 23, 2011 20:50 Post subject:

MikT725 · Posted: Mon Jan 24, 2011 19:38 Post subject:

I find this all very PHASING lol
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1999 3.1td SWB Trooper. RIP
2004 3.1td LWB

markymoan · Posted: Mon Jan 24, 2011 19:49 Post subject:

Phases on stun but they shoot to kill (I'll get mi coat)
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Gribble · Posted: Mon Jan 24, 2011 20:08 Post subject:

Thats a yellow card for going off topic I do belive ! Robbbbbooooo -

Gribble · Posted: Mon Jan 24, 2011 20:14 Post subject:

Whats this is all about is that I have a new job and got 2 weeks on job training so its handy to have a bit of extra info up the sleeve if its needed so many thanks to all the members .

Dont think I will be doing a lot of the 440v side but its safer if I know what to expect as all this new gear has 440v to 12/24dc transformers for running the PCB's and servos and solenoids plus the 3 phase motors coupled to hydraulic pumps .

marcus 06 · ** Joined: 27 Feb 2010 Posts: 96 Location: france

Got a big hammer if you need though.