sizing of a power cable between a motor and inverter drive
sizing of a power cable between a motor and inverter drive
(OP)
We have a motor that will be running a fan. It will be driven from an inverter drive. The motor info is
400V,50Hz
355kW
621A nomial current
The inverter drive info is
Output current light duty 701A
Output Power light duty 355kW
Maximum current 1000A
400V,50Hz
My question is, whgat method do you use to size the cable between the inverter drive and the motor, to get the mm^2 value? I know it has to be a screened cable as this is what ABB recommend. The clients specification wants 1.1kV grade PVC Insulation PVC Sheathed and aluminium conductors.
Thanks very much
400V,50Hz
355kW
621A nomial current
The inverter drive info is
Output current light duty 701A
Output Power light duty 355kW
Maximum current 1000A
400V,50Hz
My question is, whgat method do you use to size the cable between the inverter drive and the motor, to get the mm^2 value? I know it has to be a screened cable as this is what ABB recommend. The clients specification wants 1.1kV grade PVC Insulation PVC Sheathed and aluminium conductors.
Thanks very much





RE: sizing of a power cable between a motor and inverter drive
Resulting mm^2 will give you current carrying capacity requirement, voltage drop and EMC conditions should be checked too.
RE: sizing of a power cable between a motor and inverter drive
As to the cable diameter, that is typically determined by local codes pertaining to sizing any motor conductors, there is no special need to over size if that is what you are asking. So that will usually be dependednt upon the FLC rating of the motor, or the kW rating. Here in the US, we must use a table in the National Electric Code that is based upon motor HP, not the FLC (unless the FLC exceeds the values in the table), then the cables must be sized at 125% of those values. I would hazard to guess that codes in other countries are equally conservative.
"Will work for (the memory of) salami"
RE: sizing of a power cable between a motor and inverter drive
If you run single cores they must be run in Trefoil. If you have more than one set of single conductors, cross phasing is required. If you run a screened /armoured conductor, it must not be steel wire armoured, SWA. As the individual conductors from the starter or into the motor, it must go through an aluminium gland plate. All of this is to prevent or minimize inductive heating and cable failure.
If the motor is a long way from the VSD, then you must consider chokes as the capacitance in the cable may cause problems.
I recommend getting some professional assistance or perhaps supplysome very specific information. Sorry to be negative.
RE: sizing of a power cable between a motor and inverter drive
RE: sizing of a power cable between a motor and inverter drive
RE: sizing of a power cable between a motor and inverter drive
RE: sizing of a power cable between a motor and inverter drive
Regarding my question above. the run is less than 100m, the cables will be installed on a tray with no more thewn 6 other power cables.
The client wishes to use:
Power cables to be rated 0.6/1kV. Cable conductor (Aluminium) shall be insulated with XLPE. Cable shall also be armoured. Cable shall also contain a screen.
My question is that the terminal box has 2x M75 entries, so with the current of 623A not 621A (Sorry) what will be the maximum size of conductor that will fit the box and be able to handle the current?
Would the client be better with copper conductors?
Thanks
RE: sizing of a power cable between a motor and inverter drive
RE: sizing of a power cable between a motor and inverter drive
"Will work for (the memory of) salami"
RE: sizing of a power cable between a motor and inverter drive
RE: sizing of a power cable between a motor and inverter drive