- PT100 is an RTD (Resistance Temperature Probe) made of Platinum metal which has a resistance value of 100 ohms at zero degrees celsius. - PTC (Positive Temperature Coefficient) and NTC (Negative Temperature Coefficient) are both types of Thermistor. NTC have resistance that decreases with...

ACB and MCCB both are used for safe making and breaking of electrical systems. In principle, both serve the same purpose. ACBs are usually seen on upstream side of circuit & MCCBs on load side control (usually, load side switching operations are more frequent than upstream). Depending upon the...

Detection of phase-to-earth faults on 3-phase windings with earthed neutral, by comparison of residual current calculated from the 3 phase currents and residual current measured at the neutral point. Characteristics instantaneous tripping percentage-based characteristic with fixed slope and...

Earth fault protection based on measured or calculated residual current values: ANSI 50N/51N: residual current calculated or measured by 3 phase current sensors ANSI 50G/51G: residual current measured directly by a specific sensor.

The difference is indicated below : Closing release XF : The XF release remotely closes the circuit breaker if the spring mechanism is charged. Opening release MX: The MX release instantaneously opens the circuit breaker when energised. It locks the circuit breaker in OFF position if the order is...

International standard EN/ISO 13850 (replaces standard EN 418) specifies the functional requirements and design principles of emergency stop devices. Stop types: Stop category 0 and/or stop category 1 and/or stop category 2 stop functions shall be provided as indicated by the risk assessment and...

In a correctly designed installation, a circuit-breaker is never required to operate at its maximum breaking current (Icu). For this reason, a new characteristic has been introduced which is the rated service short-circuit breaking capacity (Ics). IEC 60947-2 expresses (Ics) as a percentage (25,...

What is vector group for transformers? A vector group is the International Electrotechnical Commission (IEC) method of categorizing the high voltage (HV) windings and low voltage (LV) winding configurations of three-phase transformers. The vector group designation indicates the windings...

issue: Customer wants to know the value of the symmetrical and asymmetrical breaking current of the circuit breaker and what do they mean. Environment: Circuit Breaker Resolution: - Symmetrical breaking current is the RMS value of AC component of short circuit current at the instant of separation...

There is often confusion between the in-phase and the In-sync features of ASCO transfer switches. It is important to understand the difference between these features especially during the process of selecting transfer switches for different applications. In-Phase The in-phase monitor is a feature...

Issue: Testing phase loss on a meter doesn't result in a null voltage reading. Environmnet: EasyLogic Series Power Meters PowerLogic Series Power Meters Resolution: The voltage seen is what we call "phantom voltage", its a known phenomenon with all high impedance power meters. These phantom...

Issue: What is an electrical "ground loop" and how does it affect my equipment? Environment: Ground loops can occur in any situation where multiple electrical devices are interconnected, especially when those devices are powered from different sources or located in different places with varying...

Issue: Having two different values for RL ( Lead resistance from the CT to the relay); RL from the phase CT to the relay and RL from the neutral point CT to the relay Environment: Protection Function ANSI 64ref High impedance differential Sepam 80 Current Transformer requirement Resolution: In any...

Issue: How do I remember the relationship of voltage, current and resistance in an electrical system? Environment: N/A Solution: Voltage (unit of measurement - volt) is like the water pressure in the pipe. When you turn on a faucet, the water pressure makes the water flow out. Similarly, voltage...

Issue: What is Power Factor Correction (PFC) - Does it help conserve energy? Answer: Explanation 1: Power Factor Correction (PFC) doesn't directly reduce the overall electric consumption of a device or system, but it does play a role in optimizing the efficiency of electrical systems, which can...

Register the Easy UPS with APC by Schneider Electric customer support. This is a one time process required to be done only during initial installation. The Easy UPS output cannot be turned on without successfully completing registration process. After successful completion of the registration...