Installation of a three phase 1.1 kW pump/motor to a PLC

[electronZ]

I have divided a big task into small sub-tasks

As the title says, I am now focusing on installing a three phase 1.1 kW 220-240/380-480 V @ 50 Hz pump to a PLC unit.
Basically how I see it, is the PLC de/activates the relay/contactor which turns on/off the supply to the pump.

I need advise and guide throug this, thank you

I see it like this:

1. Calculate the supply current used by the pump
2. Choose cable
3. Choose a relay
4. a fuse?

1. Calculate the supply current used by the pump
I understand that it is recommended to use the highest voltage supply? why? :/
That means : (1.1 kW)/(480 V)= 2.29 A ~ 2.3 A

2. Choose cable
I got a bit lost here... Found a lot of tables, some equations, and I really got lost. I cant see how to determine the voltage drop, I read around 10% for motors?
I got a value of 1.5 mm^2 3-5 meter long copper wire. How does that sound? Another way to find a cable?

3. Choose a relay
Not started yet...will be more than happy for ideas.

4. a fuse?
Is it necessory? maybe between the mains and the relay?

Thank you for your time, I appreciate it.. and many others

 

[chuckey]

1. Using the high voltage results in thinner, cheaper cables.
2. I think (in the UK at least) 10% should be 2.5%, but 1.5mm^2 looks OK.
3. Motors when they start have an inrush of 5X running current - check this on relay current ratings.
4. The best way is to use a MCB (minature circuit breaker) as close to the incoming mains supply as possible to feed only this circuit. Get a Motor rated one (type C or K?), this allows for the big inrush starting current but over a long time (10seconds) offers close current tripping - 3A. A fuse will sag due to the inrush currents wearing it out and will fail in time.
Frank

 

[electronZ]

Thank you very much Frank

 

[kak111]

Here is application note from ABB : Motor starting Solutions...........

**broken link removed**