I have a 100m underground cable run that needs to carry ~500A. We have the option of going with concentric neutral cable or tape shield. Couple of questions in evaluating cable selection and bonding methods:
1. If I go with the concentric neutral cable option, can I unground the one end to get...
I have a project involving a sub transmission line with wind turbines interconnected. Surge arresters are all along the pole line and at the base of each turbine in the switchgear with the same sizing. For some reason, the last turbine at the end of the line keeps blowing its arrester at the...
I am trying to model a Wye(ungrounded)/Wye(grounded)/buried delta tertiary transformer in ETAP. The HV side is the source of fault current and is ungrounded as specified. When I model it as a two winding transformer, I am able to select a checkbox for buried tertiary. However, when I place a L-G...
How does one calculate how much zero sequence will flow in a YYg transformer with a buried tertiary delta winding during normal operation to size the ratio of the CT on the winding?
Thanks!
In a 230 kV system, what is the thought process for leaving the H0 of a WYE-WYE transformer ungrounded?
If the HV bushings are rated at 900 kV BIL, would this make the requirement for the H0 bushing 900 kV BIL as well since it is ungrounded?
Thanks in advance!
What are your approaches to modelling transformer primary CLF fuses in arc flash studies? Currently, we do not consider them and I am not sure how to accurately model their affects in ETAP.
Thanks!
What is the general thought on lateral ties in duct bank arrangements that encircle the entire group of conduits? Would this cause heating in the duct bank and if so how would one model this in an ampacity calculation?
Hi,
I have a project that involves splicing an MV cable at an underground splice box. The cable concentric neutrals are going to be grounded at either end. My question is if a ground loop and rods are required at the splice box? My thought is that since the current will flow back through the...
I am doing the grounding design for a small padmount transformer adjacent to a building. The transformer is a delta-wye (27.6 kV-600 V) and it is connected to a 44 kV pole from the Utility with no shield wire. I am not to consider any split factors in my design.
My question is, what do I...
