We are required to design a 11kV system for a rated fault current of 25kA for 1 sec. Based on this requirement the minimum cross section of XLPE insulated Cu cable to be used comes out as 185 sqmm. The actual current required for feeder is 40A.
Now my question:
The permissible short circuit...
I have one requirement for using HFFR PE outersheath for XLPE insulated cable. I guess HFFR means Halogen Free Flame Retardent. Can anyone suggest me a cable manufacturer who supplies this. My efforts at google.com could not fetch any useful result.
Thanks in advance.
Good day gives you...
Is it necessary to employ a lighting transformer to feed the lighting distibution board from a 3P4W (TPN) source?
I understand that lighting transformer is used for reducing the fault level on the lighting DBs so that MCBs (typicall 9kA) can be used. This reduction in the rated fault level of...
Can any one one help me with a tricky issue of head loss measurement in an intake water station well with multilevel intake opening with trachracks. This intake station has 4 intakes at different levels and are provided with trashrack to prevent debris from entering th intake well. Water is...
We need to install cable at a project site where the temperature goes 30 degrees below zero during winter. Is it OK to use PVC as the insulation and outer sheath material. As per my information PVC can be used upto -5 deg C and bcomes hard and brittle at lower temperature.
Is it OK to go with...
I understand we need to derate electrical equipment rating when installed at higher altitude due to reduction in the density of air. What is the standard derating factor used for various equipment? How are the clearance and the crrepage get affected by this altitude and to what extent?
Hi,
I have an interesting scenario which I would like to discuss / share with you all.
Our client is having a cement plant (peak demand of 20MW) which is presently being fed from the utility grid sunstation “A” through a tapping. They are planning to put up a power plant of 42MW at about 2-3...
We have specified CTs with 40VA rated burden for both metering as well as protection cores, whereas the connected load is less than 10VA.
My question is whether this will have any adverse effect on the connected relays / meters? Any precaution to be taken while specifying ISF / ALF?
Regards,
SKM
For a transformer feeder, is earth fault protection required if differential protection has already been applied. If yes,any tips on how the relay cordiantion is done?
While calculating the derating factor we need to have the total no. of cables for finding group factor. Now to have the total no. of cables we need to have the derating factor. Please let me know how to proceed and which one shall be selected first. Thanx
Can anyone help me with their past experience on the usage of Restart Module or Auto Start Delay Module being manufactured by M/s Holech. What should be the duration of the starting pulse for a motor operated from Distributed Control System/ Safe Gauarding System with ASDM fitted in its module?
