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Dear All, Thanks for the replies. The first revision of installation drawing shows the pipe sleeves in duct bank arranged in trefoil. However contractor has changed to flat formation in the second revision. No one has review or realize about the changes since the it was correct in the first...

Hi All, I'm having an issue with high voltage underground cable installation in a current project. The cable is 275kV single core AWA 1Cx1000mm2, 2 runs per phase with total lenghth up to 2.04km. The cable is laid in trefoil formation up to the concrete duct bank where cables are laid in flat...

Hi all, The mcb is c-type for the lighting feeders. Lighting panel kA rating is 10. Main DB which is feeding the lighting panel is 20kA.Feeder from this DB is MCCB. My initial design for the lighting panel is based on fused switch disconnector as the incomer. However my lead engineer told...

Dear All, I have to determine the size of the lighting panel based on the total lighting fixtures connected under each circuit. My calculation is based on the data below: Total load connected = 3kW Lighting panel rated voltage = 400V 3Ph+N Outgoing feeders for lightings = 230V 1Ph+n Outgoing...

Dear All, Thanks you for your supportive answers. I have few options now and will choose the most economical solution when finalize the design.

I can use two SEL device as davidbeach pointed out. For the interlocking signal maybe I could suggest extra core in the fiber optic cable connection between the two IED. Or I can use the protocol converter as jghrist stated. But when you said 'would not be fast enough to meet your requirements...

Sorry for the late reply. I'll put in point form for a better description of the problem: 1. Downstream IED must be compatible with IEC61850 as per project specification. 2. Upstream (separate power provider)IED not necessary to follow IEC61850 and they can use whatever communication protocol...

For the interip protection, it's possible to use a converter for converting the fiber optic signal. Since there is no conversion of communication protocol but only the type signal being changed, the action should be fast enough. Please let me know your opinion.

I just want to know the upstream breaker is closed and in service position.

The interlock is to prevent downstream breaker to be closed when the upstream breaker is still open. So there must be a permissive to close signal from upstream.

The distance is about 3-4km. We are still in design stage hence the IED models are not available yet. Using a converter sounds like the feasible solution. The fiber optic cable need to go through a FO patch panel if I'm not mistaken. I need to use two/four core for the intertrip/interlocking?

Dear Experts, As per the subject, if an upstream IED using Modbus and downstream IED using IEC61850 communication, how to implement the intertrip/interlock function between them? The upstream and downstream equipment are located very far from each other where hardwire connection is not...

Oh yes!. Now I understood. Thanks guys. [bigsmile]

Dear All, Thanks for your answers. The 2 normal supply transformers 33/0.4kV and emergency supply transformer 11/0.4kV are Dyn11. They cannot be paralleled even when the secondary voltage same i.e 400V?

Dear All, We have a 400V Switchgear fed from two 33/0.4kV transformers each on bus A and bus B. Then there is emergency incomer on bus E which is fed from 11kV emergency switchgear station via a 11/0.4kV transformer. Under normal operation emergency incomer breaker is open and bus tie BE is...

I was thinking about bypassing of interlock for direct closing of breaker.It seems like there could be other possibilities as well. bacon4life, as you have pointed out the Interlocking/intertripping is not universally applied across the industry, how about its requirement on which part of...

Hi All, I've seen the intertrip and interlock function is provided for transformer feeder and incomers. Is this protection required for transformers only or can be applicable for plain feeders as well? Tripping the breaker upstream of a transformer will intertrip the downstream breaker. This...

Dear All, The lighting panel will be located inside a room in an onshore petrochemical facility. You may refer to the uploaded circuit drawing.The incomer is shown as switch disconnector (but we will use MCCB) Below the switch disconnector is the 3 pole contactor which will be used to switch...

Guys, thanks for the explanation. I have a better understanding now[smile]

7anoter4, in TNS system neutral also consider as a current carrying conductor. Wouldn't that mean the neutral also need to be isolated?