HIGH INDUCED CURRENT FOR CONTINUOUS CROSS BONDING (SOLUTION)

[jpbuntales27]

We have installed 115kV 500sqmm Cable for 6300 meter length and provided 9 JBS all Cross Bond.
When we do the testing and injected 70 amperes we are getting high current from the sheath.
Is there a solution to reduce the sheath current

R Y B
JB1 15.8 21.3 5.5
JB2 5.5 15.7 21.4
JB3 21.4 5.5 15.8
JB4 15.8 21.3 5.5
JB5 5.5 15.8 21.4
JB6 21.4 5.5 15.7
JB7 15.8 21.2 5.5
JB8 5.5 15.9 21.5
JB9 21.4 5.5 15.8

 

[waross]

Lift the grounds at one end.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[jpbuntales27]

What do you mean by Lift the grounds?

 

[waross]

As I read the drawing, you have grounded the sheaths at both ends.
Cross bonding is used to limit the induced voltages.
Current is eliminated by grounding at one end only, usually the feed end.
The sheaths are insulated from ground at the cross bonding points and at the load end.
A separate conductor is used for equipment grounding.
Another option is to let the currents flow and de-rate the cables to allow for the additional heat.
Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[davidbeach]

What voltages/currents is your test setup applying? What’s the phase angle relationship between the phases?