Interested to Buy Any Domain ? << Click Here >> for more details...
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?
- 5 Answers
- 11962 Views
- Siemens, I also Faced
- E-Mail Answers
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 |
One of our gas turbine generator unit "1st stage rotor ground fault" alarm was occured several times. we tried to measure some voltage vulue ground fault protection relay (UNS3020a made by ABB and we measured the value of: Ground: 0.9VDC 5V: 5.8VDC 24V: 23VDC u+: 300 – 350mVAC Rf1: 17.5mVAC Rf2: 17.6mVAC The unit still running and the alarm was reset. As of 6pm yesterday and unitl now no alarm happened again. I our protection relay was defective?
Why the symbol of register is "zig zag"
How much area is covered by a single lightning arrestor to protect object from lightning strokes ?
Which Current transformer will be bigger in size, 400/5 or 400/1 & why?
what r the tests on the 3 phase transformers can any one explain how to test using megger on transformers thx
ceiling fan wattages rating
why one pin of plug pin is longer than other two? In some mobile chargers one pin is made not conducting .Why?
Re: can you give main difference between ELCB 2pole And RCCB 2pole? And how this devices operated?
Why need 3phase machine double earthing?
how to checking earth restence with earthtester
If I want to use capacitor banks at HT (11 KV) side for maintaining power factor then which type of capacitor should I use? Plz give me the specification?? (I am using 1250 Kva transformer (11 KV/433V)).
in battery charging room we find two fuses (one in positive other in negative cables ).why it is so?one fuse is ore than sufficient?
-
Civil Engineering (5086) - Mechanical Engineering (4453)
- Electrical Engineering (16638)
- Electronics Communications (3918)
- Chemical Engineering (1095)
- Aeronautical Engineering (239)
- Bio Engineering (96)
- Metallurgy (361)
- Industrial Engineering (259)
- Instrumentation (3014)
- Automobile Engineering (332)
- Mechatronics Engineering (97)
- Marine Engineering (124)
- Power Plant Engineering (172)
- Textile Engineering (575)
- Production Engineering (25)
- Satellite Systems Engineering (106)
- Engineering AllOther (1379)
