Previous in Forum: Information on pump head of piston pump - KEW Brand   Next in Forum: elcb
Close
Close
Close
7 comments
Rate Comments: Nested
Member

Join Date: May 2009
Posts: 7

capacitive charging current of a cable?

05/02/2009 1:33 AM

how to calculate the capacitive charging current of a cable with open circuit power factor of 0.1?

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Power-User

Join Date: Dec 2007
Location: Brasov, Romania
Posts: 255
Good Answers: 7
#1

Re: capacitive charging current of a cable?

05/03/2009 12:02 PM

For calculating the capacitive current you need:

I=measured current

pf=0.1

it goes like: Icapacitive=sqrt(I-(I/pf)²)

Icapacitive is the capacitive current in open circuit.

the I/pf is the active component of the current, consumed in open circuit beacuse the electrical resistance if the insulation is not infinitely large.

__________________
The time is ......now
Register to Reply
Power-User

Join Date: Dec 2007
Location: Brasov, Romania
Posts: 255
Good Answers: 7
#3
In reply to #1

Re: capacitive charging current of a cable?

05/04/2009 2:52 AM

correction:

Icapacitive=sqrt(I²-(I/pf)²)

__________________
The time is ......now
Register to Reply
Member

Join Date: May 2009
Posts: 7
#4
In reply to #3

Re: capacitive charging current of a cable?

05/05/2009 12:58 AM

sqrt(I²-(I/pf)²)

I²<(I/pf)²

eg:- If I=10 & pf=.1

I²=100 & (I/pf)²=10000

Is it Possible?............

Register to Reply
Power-User

Join Date: Dec 2007
Location: Brasov, Romania
Posts: 255
Good Answers: 7
#5
In reply to #4

Re: capacitive charging current of a cable?

05/05/2009 2:15 AM

right. Sorry .

The thing was actually : Icap=I*sqrt(1-pf²)

where: I=measured current

pf- power factor

Icap= needed current

__________________
The time is ......now
Register to Reply
Member

Join Date: May 2009
Posts: 7
#7
In reply to #1

Re: capacitive charging current of a cable?

05/06/2009 12:10 AM

thanx

Register to Reply
Power-User

Join Date: Dec 2008
Location: Anthem, AZ
Posts: 392
Good Answers: 8
#2

Re: capacitive charging current of a cable?

05/03/2009 8:49 PM

Use a scope to measure the rise time of the cable when a battery is suddenly applied.

Measure the capacitance of the cable with a meter or bridge. The R can now be calculated using t=RC. Now divide the voltage waveform from step one by R to get the current waveform. I think that will be the charging current that you are asking for.

Register to Reply
Power-User

Join Date: Dec 2008
Location: Anthem, AZ
Posts: 392
Good Answers: 8
#6
In reply to #2

Re: capacitive charging current of a cable?

05/05/2009 1:54 PM

Sorry; I need to add more to my answer:

For a transient voltage, the current flow will be the derivative of the voltage wave, ( i=dV/dt). So after capturing the voltage transient, take it's derivative and plot that.

Register to Reply
Register to Reply 7 comments
Copy to Clipboard

Users who posted comments:

nikolay (3); roshanrrd (2); WoodwardDL (2)

Previous in Forum: Information on pump head of piston pump - KEW Brand   Next in Forum: elcb
You might be interested in: Cable Laying Services, Cable Assemblies

Advertisement