A contactor is a type of switch. However this switch uses electricity to power an electromagnetic coil to switch on or off power. Hence a contactor needs 2 wires - A live/hot wire and a neutral wire. Generally these are connected across the A1 and A2 terminals of the contactor.
You start with a normal one way circuit consisting of a three phase contactor and an three phase overload in series for the forward circuit. Then you add the reverse contactor in parallel with the forward contactor but with line one and line two crossed over i.e. when the reverse contactor is made, line one of the supply will be connected to line two of the motor and line two of the supply to line one of the motor. The control circuit must also be interlocked to prevent forward and reverse being energized at the same time.
with wires
Yes, when using a three phase contactor on single phase, the three phase overload block can be used. The wiring of the contactor consists of taking L1 of the supply and connecting it to L1 of the contactor. The load is connected to T1 on the bottom of the overload block. L2 of the supply is taken to L2 of the contactor. Instead of connecting the T2 to the load, the conductor is taken back to the top and connected to the contactor in position L3. The other side of the load is connected to T3 on the bottom of the overload block. The overload block has three N.C. contacts, one for each leg of L1, L2 and L3. These three contacts are wires in series to the stop - start circuit. Years ago on old schematic diagrams these contacts used to be placed on the up stream side of the magnetic starter's coil. When the overloads tripped the voltage was left on the control circuit which was found to be dangerous for trouble shooting. Now the overload contacts are positions on the beginning of the start- stop circuit so that when a overload trips, the whole stop - start circuit becomes de energized.
A single-phase cable will have a line and a neutral conductor and, possibly, but not necessarily, an earth (ground) conductor. A high-voltage three-phase cable will have three line conductors. A low-voltage three-phase cable is likely to have three line conductors and a neutral conductor.
A contactor is a type of switch. However this switch uses electricity to power an electromagnetic coil to switch on or off power. Hence a contactor needs 2 wires - A live/hot wire and a neutral wire. Generally these are connected across the A1 and A2 terminals of the contactor.
A 3-phase system has three terminals: one for each phase (labeled A, B, C). Each phase is connected to one of the three wires in the system.
To use a 3 phase contactor in a single phase installation, one approach is to connect your single phase supply to any two of the three contactor terminals. Ensure that the coil voltage matches your power supply voltage. The contactor will function normally by controlling the single phase load connected to its output terminals.
All capacitors fundamentally have two sides or "connections" so that any single capacitor will have two terminals. That is true whether capacitors are used in single phase (using one or more capacitors), or in three phase power (same number of discrete capacitors on each phase). The packaging of capacitors is mostly as "singles" having just two connecting wires or terminals, but certain applications - such as three-phase motor speed controllers - often use "blocks" of three or more capacitors, packaged together into one "body" or "casing". Those "capacitor blocks" have four or more connecting wires or terminals.
I'm unable to draw diagrams, but a typical 3-phase electric meter base will have three current transformers for measuring the current in each phase, and three voltage terminals for measuring the voltage across each phase. Each phase will have a connection point for the load wires coming from the main electrical panel. Additionally, there will be output terminals for connecting to the utility company's power lines.
Three wires carry the three phase energy.
Three phase or two phase? Three phase requires three large wires for the current needed
If single phase - 2 wire service > two wires If single phase - 3 wire service > three wires If three phase - 3 wire service > three wires If three phase - 4 wire service > four wires US residential service is usually single phase 3 wire service: Two hots and neutral.
You start with a normal one way circuit consisting of a three phase contactor and an three phase overload in series for the forward circuit. Then you add the reverse contactor in parallel with the forward contactor but with line one and line two crossed over i.e. when the reverse contactor is made, line one of the supply will be connected to line two of the motor and line two of the supply to line one of the motor. The control circuit must also be interlocked to prevent forward and reverse being energized at the same time.
with wires
Most electrical equipment are either designed to work on Single phase (two wires) or Three Phase (three or four wires). Two phase equipment are non existent today. A single phase heater will require a single phase thermostat while a three phase heater will require a three phase thermostat.
Yes, when using a three phase contactor on single phase, the three phase overload block can be used. The wiring of the contactor consists of taking L1 of the supply and connecting it to L1 of the contactor. The load is connected to T1 on the bottom of the overload block. L2 of the supply is taken to L2 of the contactor. Instead of connecting the T2 to the load, the conductor is taken back to the top and connected to the contactor in position L3. The other side of the load is connected to T3 on the bottom of the overload block. The overload block has three N.C. contacts, one for each leg of L1, L2 and L3. These three contacts are wires in series to the stop - start circuit. Years ago on old schematic diagrams these contacts used to be placed on the up stream side of the magnetic starter's coil. When the overloads tripped the voltage was left on the control circuit which was found to be dangerous for trouble shooting. Now the overload contacts are positions on the beginning of the start- stop circuit so that when a overload trips, the whole stop - start circuit becomes de energized.