Remote Gate Supply

[skiandy]

Hi I have been asked to quote for a supply to a remote electric gate only problem is we have calculated the cable run to be 500 meters from the supply. Does anyone have any advice please.

 

[UNG]

What voltage does the gate need

 

[skiandy]

3 P, N & E control gear is 230V.

 

[ian.settle1]

3 P, N & E however control gear is 230V.

Some more details about the motor size etc would be helpful

 

[skiandy]

The motor is 0.6 KW, and there is a Card reader which pulls negligible current.

 

[Laner-Sparky]

600watts / (400v x 1.732)
0.88Amps per phase.

If we assume a power factor of 0.85 then we have 1.01amps per phase.

Now that run is rather a large one, voltage drop allowance of %5 so 20v for 400v.

Usually a 1mm 3-phase cable would be fine for a 1.01amp load per phase, but with a 500m run you would have a voltage drop of 21.21v at MV/A/M of 42.0, just that little bit to much, so go with a 2.5csa cable to be safe, 3-phase N/E, thats a voltage drop of 8.5v, and so this is ok.

Id go for a 6amp 3-phase C curve MCB, 2.5 3-phase SWA cable.

Hope that helps.

 

[skiandy]

Thanks,

I pretty much agree with that.

What do you think the highest ambient temperature that the cable could reach in a summers day, just curious on this one.

 

[chris gray]

how are you going to route it?

 

[skiandy]

Cable tray is already installed

 

[Laner-Sparky]

I suppose in the UK around 35 degrees on an insane summers day brought about by global warming, if clipped direct onto a tray above ground.

The ambiet temp correction factor for 35 degrees would be 0.94

So for example if a 2.5 twin & earth had a current carrying capacity of 27A, with a correction factor of 0.94 it would go down like this.

27 x 0.94 = 25.38

Obviously thats the current carrying capacity for a twin & earth PVC cable, not an SWA, so dig out your on site guide for a more accurate result.

But either way the ambiet temperature wont be a problem if you install a 2.5 3-phase SWA cable to your motor.