We use ungrounded DC system (220V/110V) for control and
protection system in substations etc. Suppose we have long
2 core DC cables running from our DCDB in control room to
the load (length of around 2 to 3 km). Do we need to
protect these long DC cables from earth leakages or not? If
yes how?
Answers were Sorted based on User's Feedback
Answer / krishna
Usage of differential relay for 220V/110V is not an
economical idea. Differential protection is the costlier
protection. DC Cables should be protected from earthleakage
bacause of which voltage differences occurs and trips the
circuits due to large variations. I suggest to go for
MCCB/MCB of required rating which trips the circuit when
earth leakage occurs.
Is This Answer Correct ? | 5 Yes | 1 No |
Answer / ch.shankar
use dc differential relay or poles insulation monitor which
will help u to measure leakage
Is This Answer Correct ? | 5 Yes | 3 No |
Answer / k.prakashchandra
Normally dc earth fault locater is employed. If one polarity
shows earth fault there is nothing to panic.Heavy fault
current occurs if the other polarity also develops fault. If
tripping is provided ,the protection may get lost.
Is This Answer Correct ? | 1 Yes | 0 No |
Answer / sanjay choubey aditya electron
You can use online Insulation Monitor Bender Germany make
products for above requirement you can also see website for
more details: www.bender.org many Steel Plant, Substation
are using Bender products same applicaton.
Is This Answer Correct ? | 1 Yes | 0 No |
Answer / sanjay
You can use online Insulation Monitor Bender Germany make
products for above requirement you can also see website for
more details: www.bender.org many Steel Plant, Substation
are using Bender products same applicaton.
Is This Answer Correct ? | 0 Yes | 0 No |
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