BUSBAR PROTECTION TRIP

1.In transformer feeder busbar protection will operate both the High side breaker and
lower side breaker

2.BF stage -1 and BB protection will initiate TC1 & TC2 of all breakers.

MICOM 142 DOCR TRIPPING CONDITION

Relay will trip single phase faults reference with other phase voltage

For three phase fault relay will take last one min memorised RYB voltage.

If one hour maintenance shout down memory voltage will errised then any bady switch on the CB with three fault there is no voltage in memory and relay will not operate for this fault.But in Line protection relay SOTF will operate.

RED 500 to DTR CONNECTION

RED 500 to DTR RJ pin connection (1 2 3 4 5 6) to ( 3 6 1 4 5 2 )

SCADA & SOE PAIR CABLE

Pair cable shield wire should be grounded at one side for Analog points
to avoid the error in the reading and out side noises effects.

HI - POT LEAKAGE CURRENT

How to calculate the Hi-pot leakage Current?

I = U X 2пcf

U = Applied voltage
c = Total capacitance = Instrument Capacitance + Circuit Capacitance
f = Frequency applied = 1/2п√CL

Note: Circuit Capacitance can measure with IR value measurement kit.

VACUUM IS A CONDACTOR

Vacuum will become a conductor in some potential stage.So don't do any
electrical test in equipment

CT CONNECTION TIPS

CT CONNECTION TIPS

1.For Bus section and Bus coupler The CT "P1" should be Breaker Side

CT METERING CORE STAR POINT

CT Star point connection for metering core should be towards line or cable or transformer side.

In energy meter IMPORT reading should be -ve sign
EXPORT reading should be +ve sign

In line feeder power towards bus and current develop 180 dec displaced and
Energy meter shows -ve reading.(Power inter in earthing point side P2 side)

In cable feeder power outwards to bus and current develop 0 dec displaced and
Energy meter shows +ve reading.(Power inter in side P1 side)