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Thanks for your reply. So as I understand, the crank relay initially cranks the engine with the help of starter motor. Once certain speed (say 300RPM) is reached this relay de-energizes. At the same time, the engine goes into run state now and hence energizes the run relay that initiates the...

This is an scheme of LCP (Local Control Panel) in DG SET. Here the controller gets input from AMF panel. I was just wondering what is difference between DG Crank & DG Run relay R1 & R2 (just asking in general about the sequence of operation). As I have read a DC supply from battery needs to...

Thanks for your reply. It makes sense when we do I2/I1 = N1/N2. But when you think about it primary winding resistance is so minimal (in terms of few ohms), then what exactly is stopping that heavy current to flow between Primary Phase A and N (E90). Like what law of magnetism is working to stop...

Hello, As you can see above is an electrical diagram of Bus PT for 11kV Bus. I have a question that if the primary winding of PT is Star Connected with Neutral point earthed, then why does it not carry extremely high current when connected to 11kV? (Ex. I = (11kV - Vn)/ Zwinding as per KVL)...

Hi all, I was wondering does the insulation resistance value change with applied voltage? For ex. lets say if I have an equipment and I test it with 2.5kV and get X value of IR. Does this value change if I conduct the same test with 5kV? Best! Chris

(a) But let's say if initially my phase sequence is R Y B, my triggering angle is 30 degree for T1 when R phase is connected to anode of T1. Now if I were to change my phase sequence to B R Y such that B phase is now connected to anode of T1. In the second case will the triggering angle of 30...

Hello all, Lately been struggling to get the answers to these questions, Q.1 Does phase sequence/ phase shift in input AC supply affect rectified DC output in fully controlled rectifier? Q.2 How does the triggering angle of rectifier change automatically in a practical fully controlled...

Thank You very much @7anoter4. So it is to stop from Sheath Voltage to Rise Beyond Limits sustainable by SVL (To dissipate the Energy during Fault)

Dear all, The types of sheath bonding that are generally used for Cables is (a) Single Point (b) Both Point Bonding or (c) Cross-Bonding But as we know that generally when using Single Point or Mid Point Bonding we provide with the SVL to limit the sheath voltage. What is the requirement of...

Dear all, Generally we use Copper Screens/Copper Tape in XLPE Insulated Cables to meet the fault current. Can it be replaced with Aluminium Screen? By screening I mean round wire of Aluminium since for 1C Cables we already use Al Armour. So why not use it for screening purpose in 1C and 3C...

Dear friends, Is there any relevant IEC or other standards clause that discusses the suitability of EHV Cables for high altitude? Laying Conditions: Underground Altitude: > 1000 m Cable: XLPE Insulated 220 KV, 1200 sq.mm - Unarmored Cu Cable (2XLyC2Y)- which is Copper Conductor, XLPE...

Hello Everyone, Someone asked me to perform Heat Load Calculation for Power Cables. As Electrical Engineer we always do the I^2.R Calculation. But how do we calculate HVAC (Heating, Ventilation, Air Conditioning. Question Asked : Also when I performed the loss calculation is for Per...

I tried that, I didnt understand how exactly to open that data?

The offered 400sqmm Bare copper conductors are used for substation Busbar arrangement and equipment jumper connection. The Copper Conductor we offer is Soft. 59/2.92mm (Strand/Dia of strand) Do I need to look into one of these right: https://www.powerlinesystems.com/generic-nonlinear-copper...

Dear Friends, We are supplying a 400 SQ.MM Bare Copper Conductor (Hard Drawn - HDCC) for Customer Substation Application for Busbars and Jumper Connection. Any idea how to get this data? I think PLS - CADD has similar interface. Thanks Chris

In Single End Bonding there is no circulating current. Hence Cable Ampacity is not reduced due to circulating current flowing in earthed sheath.(Because its only earthed on one end, hence no closed path) Cable Derating in Ampacity is due to many factors like Formation, Earth Resistivity...

Check this Comparison by ABB (OEM) https://search.abb.com/Library/Download.aspx?DocumentID=2750%20515-136&DocumentPartID=&Action=Launch Good Luck!

@Davidbeach Thanks, really appreciate inputs from everyone. So many experienced people here. I get to learn a lot.

@7anoter4 So basically the copper screen was not grounded rather live due to bad workmanship. My only worry is why does it cause fault to take place somewhere in middle of cable? Also remember there was no load @Kiribanda Single End Bonded (Only the Copper Screen) (Armour Open) @che12345 Nice...

@Little Inch You mean synchronization just to allow a zero break transfer from UPS to Mains right?