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Topic Title: dc tripping unit for HT Topic Summary: Created On: 06 March 2013 12:07 PM Status: Post and Reply |
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 06 March 2013 12:07 PM
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What is DC tripping unit?,
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07 March 2013 09:46 PM
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Depends on the manufacturer and the type of switchgear.
It can consist of anything from the battery system, protection relays, interlock circuits and tripping coils or combinations of the above. It will be responsible for tripping the latch mechanism holding the primary circuit contacts closed. Kind regards Donald Lane |
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08 March 2013 03:37 AM
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Depends on the manufacturer and the type of switchgear. It can consist of anything from the battery system, protection relays, interlock circuits and tripping coils or combinations of the above. It will be responsible for tripping the latch mechanism holding the primary circuit contacts closed. Kind regards Donald Lane Hi Donald, wht is the voltage of the battery percell?, the dc voltage for relay usually is 30V DC |
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08 March 2013 10:32 PM
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Personally I have never come across a 30V system.
I have seen 24V and 48V systems that were derivatives of 12V battery cells. Larger systems I have worked on have been from station battery systems of 120V or 220V. The cell voltages for these systems was 1.2V sealed lead acid or wet cells. Kind regards Donald Lane |
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09 March 2013 01:36 PM
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30V DC used to be very common in distribution substations. To me a DC tripping unit is a self contained charger/battery unit. In distribution substations they are often a wall mounted unit apox 900 wide, 500 high by 300 deep. The tripping unit is fed from a 13A socket or 20A DP switch and there are one or two out going circuits.
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10 March 2013 06:50 PM
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Many ground-mounted secondary substations use self-powered relays and tripping coils (with the necessary power derived from the protection CTs).
When Emergency Tripping facilities are needed (eg when the customer takes a supply at 11kV), the power supply for this is frequently derived from a capacitor which is charged from the metering VTs. ------------------------- Jonno |
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dc tripping unit for HT
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