Table of Contents
Where is CT installed?
Key Points. Install CTs on the phase conductor that corresponds to the voltage input phase. Install CTs with the arrow or label ‘This side toward source’ facing towards the breaker feeding the load.
Why is CT placed before circuit breaker?
A current transformer (C.T.) is used where the current is too high to measure directly, or the voltage in the primary circuit is too high, so the galvanic isolation between primary and secondary is important for safety or technical reasons.
What does the dot on a CT mean?
White Dot – Some CT’s may have a white dot, or a dot of another color, like green, blue, or red. The dot only serves as an indication of the side of the current transformer intended to face the source of electricity, or line side, the high side. The dot should face that high side, the source of electricity.
How do you connect CT and PT?
The primary winding of the current transformer is connected in series with the transmission line whose current is to be measured whereas the potential transformer is connected in parallel with the line. The core of the current transformer is built up with the laminations of the stainless steel.
What is a CT transformer used for?
A CT which is short for a current transformer is an electrical material which is used for metering, over current and deferential protection. By metering, I mean it is used to read the current flowing through an electric circuit. Also, by protection, it is used to protect devices under its zone of protection.
Where are CTCT’s mounted in a circuit breaker?
CT’s mounted inside the CB (CT’s on both sides of CB) CT’s are on the circuit side of the CB However the risk of a fault between the current transformers and the circuit breaker and within the circuit breaker itself is very small and so the economics of accommodating the current transformers may have an important influence on their location.
Where are current transformers mounted on a power transformer?
Current transformers can be mounted on the low voltage or high voltage leads of a power transformer. Sometimes a section of a bus bar can be removed to replace a current transformer.
What is the use of neutral CT in a neutral transformer?
So Neutral CT is connected between neutral points of two stars to measure neutral unbalance current. This neutral current transformer’s output is connected to neutral unbalance relay to trip the capacitor bank in case of fault in any phase that will cause unbalance in the neutral CT.