Different Current at Same Phase

You might have copper in the cables.

That copper might carry current and the current might heat up your cable.

The difference in currents points to unequal loads or the distribution of your load over the cables.

Are the begin- and end points of the phase connected together?

Have the cables the same length?

How hot is hot for you?

630 mm are short cables, you have something to add?

all cable same length

this connection from substation breaker to load main breaker

this means the four cable have direct connection

temperature very hot at connection point reach 70 c " at cable lug "

40 c after one meter from connection point

cable length 100 meter

Your problem is where it is getting hot. Make sure your terminations are clean and tight.

problem with cables whose high current or low current ?

Each phase have two cable

Not sure this is as per code but seems you have one cable carry more so it gets hotter than the other one.

Maybe the concept of two cables per phase is wrong and you better go with one that can take the full load.

each phase have four cables

this is other record after we decrease the load

no way to use one cable , we are using 4*3*630 MM+2N630+G

Then there is something wrong with cable 1 phase 2, cable 2 phase 1, cable 3 phase 3 and cable 4 phase 2. Surprisingly perhaps, they cannot be seen from here.

I'm not certain of your configuration from the language you've used so I must make some WAG what might be your concern or even if you have a true problem. If these cables are not wired in a trefoil configuration then some of the heating may be induction heating of the ferrous supporting material around these cables.

I am worried about the current handling capacity of this cable and what your distant loads are drawing. Unless these cables are suspended in air then you have exceeded the recommend maximum current with all phases of cable 2 & 4. If they are in air then only cable 4 phase #1 is close to the maximum.

As for the current balance, only your load sets the currents drawn. No amount of cabling or contact conditioning can change that.

1. You have a problem you do not understand.

2. You have not provided sufficient information to allow people half a world away to adequately troubleshoot the problem for you.

3. Using the "I have an undefined problem, please correct it for me" approach will never cause the problem to fix itself.

4. Hire a local, qualified electrician to come to your facility and troubleshoot and repair the problems with your circuit installation. Granted, this approach is not free of cost.

It is better to light the candle of qualified help than it is to struggle in the darkness of helplessness.

I have a pretty good suspicion of what is causing it but since you posted anonymously I will have to keep my thoughts to myself.

No name no answers from me.

Is mohamed123 theOP?

It doesn't look like Stinky Pete...

You have stated 4 Nos. of Cables. From your posting it is not clear whether 2 cables are bunched together and connected to R,Y, B OR eachcable Red color is connected to R Phase, Yellow colour is connected to Y phase and Blue color is connected to B phase.

If you have bunched the cable and connected, it will cause over-heating and un-balanced current. Pl. clarify so that suggestion can be made.

DHAYANANDHAN.S

each cable Red color is connected to R Phase, Yellow colour is connected to Y phase and Blue color is connected to B phase.

4 _CABLE *3_ PHASE *630 MM

630mm is a very short cable.

Would that be 630mm² cross sectional area instead, please?

Cable length 100m as per post above!

Its like pulling teeth!

Sir,

Now 3 runs of cable from drive to Motor 240sqmm of 200mtr distance.

it is Delta connection,R,Y,B OF Each cable bunched.

heat is like that after 1 to 2 month terminalas got heat up.

As has been said, you must ensure the cables are grouped RYB

If you have them laid RRR YYY BBB NNN then you will get this problem, we have seen this many times when testing switchboards, as you have said the current in some cables can be double and that is only over a very short length of ~ 5M

and that is only over a very short length of ~ 5M
did you means if RRR YYY BBB sequence happened on short area, causing this problem ?sure this actually occured on my case where on the connection ends at both side all cables mixed in around 4 ~ 5 meter
kindly ensure

Yes

It was a test assembly and the lab were not carefull where they dropped the cables from the bars, it was easier for them to run RRR YYY BBB, to the transformer, but it caused lots of problems.

You need to ensure the cables are bunched very quickly after the connection to the assembly and remain in RYB RYB RYB format along their length

Dear 3PhaseDesign-Craig
did you means if RRR YYY BBB NNN sequence happened on short area, causing this problem ? .
sure this actually occured on my case where on the connection ends at both side all cables mixed in around 4 ~ 5 meter
kindly ensure

cross phase induction ?

Al or Cu?

cu
insulation : XLPE/PVC

Al cable

Are you using a separate cable for each phase installed in individual conduits?

If so, the heating is most likely being caused by the magnetic flux interaction between the conductors.

All three phase conductors must be installed in the same conduit in order for the magnetic flux to cancel out.