1. PROBLEM OF SPILL CURRENT WITH RESIDUALLY CONNECTED
C.T.s DOES NOT EXIST WITH C.B.C.T
NO NEED OF STABILISING RESISTOR AS C.B.C.T. OPERATES
ON FLUX BALANCE PRINCIPLE
PICK UP SETTING AVAILABLE ARE LOW ENOUGH TO
DETECT GROUND FAULT CURRENTS OF FEW AMPS
e.g. MINIMUM PICK UP AVAILABLE FOR
CTMM / SPACOM : 10 MILLIAMPS
HIGH RESISTANCE GROUNDED SYSTEM
CBCT APPLICATION
EARTH FAULT (ZERO SEQUENCE) PROTECTION KR

2. EARTH FAULT (ZERO SEQUENCE) PROTECTION
HIGH RESISTANCE GROUNDED SYSTEM
FOLLOWING INFORMATION SHALL BE FURNISHED TO C.B.C.T
MANUFACTURER
OUTER DIAMETER OF CABLE OR CABLE SIZE
MINIMUM PRIMARY GROUND FAULT CURRENT TO BE DETECTED
RELAY BURDEN AND SETTING RANGE OF RELAY
CAUTION : DURING INSTALLATION, BEFORE THE CABLE
ENTERS C.B.C.T, CABLE ARMOUR HAS TO BE EARTHED;
OTHERWISE GROUND FAULT CURRENT FINDING PATH
THROUGH ARMOUR RESULT IN NON-OPERATION
OF THE C.B.C.T KR

3. I.M I.M I.M 50N 50N 50N i = 0 i = 0 i = 0 APPLICATION OF CBCT
EARTH
EARTH
EARTH
FAULT
FAULT
FAULT
APPLICATION OF CBCT
CORRECT POSITION OF ARMOUR EARTHING KR