generator and neutral

[blakeyat48]

my friend has a stand alone 3-phase generator which is supplying a shredder he has asked me to install a compactor to the generator as well,from the generator there is a swa cable off two the shredder control box where the neutral cable is bonded to the casing?now my question is am i right to assume that this point is used as the generators connection between neutral and earth and if so can i also use this as the nuetral point to get 230v for the control circuit. or do i disconnect it and install a henly block and rely on the swa as earth back to generator and assume that somwhere in the generator the nuetral is linked to the casing.not much experiance on generators any help would be handy.

 

[JD6400]

The first thing i would say is never ever assume , especially with what could be your only means of earth !
Sounds wrong to me and i would not leave it like this , i have never seen that one before ?
There will no doubt be someone with a intricate knowledge of generators along soon .

 

[benji]

you need to check if the star point on generator has been earthed and where to,because your nuetral will/should be connected to it

 

[blakeyat48]

thank you for your answers i will check as i have said before i have no knowledge of generated power it might be as the shredder does not require a neutral (3-phase)they have connected it to earth ie pme style in that case i should be able to disconnect it from the casing and use this as the nuetral as this will be connected in the generator to earth where else can you get a nuetral.

 

[Engineer54]

You haven't told us the rating of this generator?? ....so rating please!!

Make absolutely sure that the neutral point at the generator is solidly grounded, and that the mounting frame is also bond down to earth. Remove the neutral /earth connection at the control box. Make sure first, that it is actually a neutral and not a 4th core used as an earth along with the SWA, that hasn't been suitably identified.

As a rule you don't multiple earth the neutral on a generator set-up, you can get all sorts of stray currents running all over the place. Which is why 3 phase Generator supplies will normally call for 4 pole isolators etc....