Circuit for 28KW four motor saw machine.

[treehouse]

Hello, I am looking for some experienced advice regarding two areas of an installation I have been asked to look at. It involves providing a circuit for a saw machine which has a total power rating of 28KW. Firstly in spite of my calculations indicating a 16mm supply would suffice, the parent company responsible for the machine are recommending 35mm! I will be fitting the latter but would welcome your thoughts. Secondly as I believe it's installation will stretch the capacity of the existing DB I want to run the machine on it's own 3P&N supply. Am I right or wrong in thinking that connection from the mains to a fused isolator and then to the machine (where each phase has a 100A fuse) will provide the required overload protection and no MCB will be required. Thank you

 

[netblindpaul]

What is the start up sequence for the motors, are they DOL, Y/D?
If the machine builder, which is what I take from your OP has fused the machine @ 100A on the incomer, what fuses are these?
Is the OEM expecting to need 100A fuses, if so they may be expecting a 100A supply for it to be stiff enough.
Your explanation of the supply side connection is inadequate to make any suggestions tbh.

 

[ian.settle1]

Hello, I am looking for some experienced advice regarding two areas of an installation I have been asked to look at. It involves providing a circuit for a saw machine which has a total power rating of 28KW. Firstly in spite of my calculations indicating a 16mm supply would suffice, the parent company responsible for the machine are recommending 35mm! I will be fitting the latter but would welcome your thoughts. Secondly as I believe it's installation will stretch the capacity of the existing DB I want to run the machine on it's own 3P&N supply. Am I right or wrong in thinking that connection from the mains to a fused isolator and then to the machine (where each phase has a 100A fuse) will provide the required overload protection and no MCB will be required. Thank you

Shall we all get our crystal balls out as you haven't give us much info to go on except 28kw loading, no distance from DB, grouping off cables, how your going to run it etc just to name a few

 

[MDJ]

Gasp!!!!!!

 

[Outspoken]

Shall we all get our crystal balls out as you haven't give us much info to go on except 28kw loading, no distance from DB, grouping off cables, how your going to run it etc just to name a few

Exactly, stating a rating is about as much help as a poo sandwich if you fail to provide the all important and crucial additional information, why not provide a link to the machine online so we can assess it and then provide a bit more advice, but the circuit length and the the environment/installation method are needed, in fact crucial once you start getting into loads of this type...

I am reading posts on this forum and thinking..."Do they teach them anything at college these days"

 

[Knobhead]