Why ammeter is connected in series
Ammeter is a device used to measure the current flow through a conductor. The name is derived from the unit of current, Ampere. Ammeter is either connected in series to…
Difference between circuit breaker and isolator
Isolator/ Disconnectors
Isolator or disconnectors, as the name indicates, is a switching or isolation device, intended to disconnect an equipment or electrical Circuit from the supply. It is an offload device, which means it can be operated only when the current passing through it is zero. Unlike circuit breakers, it lacks a built-in arc suppression system. It can be operated only during offload conditions. (more…)
Transformer Action
Transformer action is a phenomenon by which EMF(Electro-motive force) is induced in from one coil to the other coil by electro magnetic induction. It is the basic principle of electric transformers.
What is meant by B, C, D, K and Z curves in MCBs?
MCB (Miniature circuit breaker) is a re-settable device designed to protect a circuit from short circuits and overcurrents. Trip curves of MCB's (B, C, D, K and Z curves) tell…
Difference between MCB and RCBO
MCB – Miniature Circuit Breaker and RCBO – Residual Current Circuit Breaker with Overload Protection are circuit protection devices. These devices are commonly used in low voltage power distribution and can be seen in distribution boards in homes, offices, commercial buildings etc.
What is meant by stalling of motor?
Stalling is a condition at which a motor stops rotating even when there is sufficient voltage at it’s terminals. This condition occurs when the torque required by the load is more than the maximum torque (Breakdown torque) that can be generated by the motor. At this condition, the motor drains the maximum current and the speed comes zero.
Difference between MPCB and MCCB
Motor Protection Circuit Breakers and Moulded Case Circuit Breaker and are devices used to open and close a circuit manually and interrupt the circuit automatically on the occurrence of faults. MPCBs and MCCBs are used to protect against overload and short circuits. Application of Motor Protection Circuit Breaker is entirely different from that of Moulded Case Circuit Breakers.
Difference between RCCB and RCBO
RCCBs and RCBO are residual current protection devices. Residual current protection is achieved by monitoring the flow of current in the line and neutral. In a healthy circuit, the current flow through the line will be equal to the return flow in the neutral. In the case of any abnormalities, this return flow may not be equal to the current flow in the line. Residual current devices sense such scenarios and interrupt the circuit.
What will happen if a DC voltage is applied to the transformer coil?
This is a very common question asked by those who are starting up with transformer science. You may come across the same question during interviews too. (more…)
Difference between MCCB and RCCB
Difference between MCCB and RCCB
MCCBs and RCCBs are circuit protection devices with two different application. When the former protect against overload and short circuit, the later protects against Residual currents and electric shock.