The WattNode® Pulse meter is a true RMS AC watt-hour transducer with pulse output (solid state relay closure) proportional to kWh consumed or produced. The WattNode Pulse meter provides 0.5% accurate kWh measurements at low cost to meet your needs for sub-metering, net-metering, energy management, and performance contracting applications. The WattNode pulse family measures 1, 2, or 3 phases in 2, 3, or 4 wire configurations. With voltage ratings from 120 to 600 Vac and current transformer (CT) ratings from 5 to 6000 amps, there is a meter and CT combination to measure all types of electrical services.
Diagnostic LEDs provide a per-phase indication of line voltage, positive energy (green flashing) and negative energy (red flashing) to help troubleshoot connection problems, like swapped CTs, or excessive line voltage. See the manual for a full description.
(Not available on WattNode Revenue Models)Option P3 provides three separate pulse output streams, one pulse output channel per measurement phase, which can be used to monitor each phase of a three-phase circuit independently or to monitor three separate single-phase circuits with one WattNode meter.
(Not available on WattNode Revenue Models)With Option 2N1, one model of WattNode Pulse meter can be used for monitoring either two single-phase circuits or one multi-phase circuit, simplifying ordering, stocking, and installation.
Single Phase Circuits: Analysis, with phasor diagram, of circuits with R, L, C, R-L, RC, R-L-C for series and parallel configurations. Real power, reactive power, apparent power and power factor.Three Phase circuits: Advantages of 3-phase power, Generation of 3-phase power, Three-phase balanced circuits, voltage and current relations in star and delta connections. Measurement of three-phase power using two wattmeter method.
Three Phase Synchronous Generators: Principle of operation, Constructional details, Synchronous speed, Frequency of generated voltage, emf equation, Concept of winding factor (excluding the derivation and calculation of distribution and pitch factors).Three Phase Induction Motors: Principle of operation, Generation of rotating magnetic field, Construction and working of three-phase induction motor, Slip and its significance. The necessity of starter, star-delta starter.
Type Z MCBs are highly sensitive MCBs that operate for a current value between 2 to 3 times the rated current with an operating time of less than 0.1 Second. They are used with more delicate devices prone to short circuits, such as semiconductors.
A four-pole MCB contains four switches, three phases, and a neutral. But unlike the three poles with neutral, the four poles protect all the phases and the neutral. They are used in places with an unbalanced circuit.
Standard 3-phase circuits or networks take on two major forms with names that represent the way in which the resistances are connected, a Star connected network which has the symbol of the letter, Υ (wye) and a Delta connected network which has the symbol of a triangle, Δ (delta).
If a 3-phase, 3-wire supply or even a 3-phase load is connected in one type of configuration, it can be easily transformed or changed it into an equivalent configuration of the other type by using either the Star Delta Transformation or Delta Star Transformation process.
Both Star Delta Transformation and Delta Star Transformation allows us to convert one type of circuit connection into another type in order for us to easily analyse the circuit. These transformation techniques can be used to good effect for either star or delta circuits containing resistances or impedances.
The solid-state electronic sensing circuitry drives an internal DPDT relay, allowing the Model 2644 to operate two motor control circuits, or a control circuit and an alarm circuit. An adjustable trip delay reduces or eliminates nuisance tripping caused by momentary voltage fluctuations on motor start-up. An optional restart delay gives approximately a 3.5-minute delay when the relay drops out, to allow compressor head pressures to bleed off, in the event of short-term power failures.
The Model 18 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 18 monitor will detect phase loss on a loaded motor even when regenerated voltage is present.
This device consists of a microcontroller with a voltage and phase-angle sensing circuit, driving an electromechanical relay. When correct voltage and phase rotation are applied, the internal relay will energize. A fault condition will de-energize the relay. When the fault is corrected, the monitor will automatically reset. An adjustable restart delay prevents short cycling in compressor applications and an adjustable trip delay prevents nuisance tripping during power fluctuations.
The Model 19 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 19 monitor will detect phase loss on a loaded motor even when regenerated voltage is present.
If a three-phase motor is to be driven in only one direction, and upon its initial energization it is found to be rotating opposite to what is desired, all that is needed is to interchange any two of the three line leads feeding the motor. This can be done at the motor starter or at the motor itself.
Once two of the lines have been switched, the direction of the magnetic fields created in the motor will now cause the shaft to spin in the opposite direction. This is known as reversing the phase rotation.
If a motor is to be driven in two directions, then it will require a Forward / Reverse motor starter, which has two three-pole horsepower-rated contactors rather than just one as in the conventional starter. Each of the two different motor starters powers the motor with a different phase rotation.
When designing the control schematic for forward / reverse circuits, we start with the standard three-wire circuit, add a second normally open pushbutton, and add a holding contact branch for the second coil. A single stop button is sufficient to disable the motor in both directions.
The direction that a three-phase motor spins is determined by the phase sequence of the voltage impressed upon it. To reverse the direction of the motor we simple reverse the phase sequence by switching any to line leads. 2b1af7f3a8