3 phase on TT?!?

[danielson_39]

I'm going to be doing an install on an existing warehouse unit soon, (mez floor offices dado trunking lighting etc) I went and put a supply into the temp office the other week and noticed that the supply is 3 phase and on a TT. Has anybody else come across this? The install is relatively new and not in a remote area, just found this really strange and was wondering if anyone else had come across this?

 

[i=p/u]

is what it is i suppose

 

[malcolmsanford]

It is a rare beast especially if it's a commercial unit.

I've know a few older farms in the sticks to be all TT 3 phase, but most commercial units are built around other units and these "ëstates"would have their own sub and and would be TNC-S even post war ones.

 

[D80]

Only times I have come across 3 phase TT systems is in domestic properties. Back in the day they had electric heating and have just been modified a little since so the old heating points would now be sockets.

 

[danielson_39]

Like I said a strange one, nice brand new cut out with "no PME" stamped on it, can see them having trouble with the RCD's time delay or not once there's a load of computers and machinery in there!!

 

[Rockingit]

Might be worth the call to the DNO engineering team just to ask them why it is that way. It might be that they couldn't satisy Ze on installation for some reason.

 

[danielson_39]

Yeh I mentioned it to my gaffer and he said he would do some enquiries,