Allen-Bradley 80026-007-02-R RETURN SPRING 1.77I/D X 4.30

Allen-Bradley 80026-007-02-R RETURN SPRING 1.77I/D X 4.30

The vacuum contactors are designed for high horsepower applications in the2400…7200V range. These contactors are suitable for all types of AC loads, forexample: three-phase motors, transformers, power capacitors, and resistiveheating loads. Mechanically latched contactors are used in situations thatrequire the contactor to remain closed during a power failure.The contactor uses three interrupters (referred to as vacuum bottles) operatedby an electromagnet assembly through a mechanical linkage. They areresistanttoadverse atmospheric conditions and provide a long mechanical and electricallife.The contactors are used in various starter and drive configurations. They arefixed-mounted in the structures and the line and load terminations are made atthe rear of the device. In mostconfigurations, the main contactor ismechanically interlocked with the external operating handle and isolationswitch.

Vacuum Bottle Description The vacuum bottle (Figure 1) consists of two contacts that are enclosed in aceramic housing. One contact is mounted on a fixed shaft, and the other isattached to a movable shaft. The bearing and stainless steel bellows verify thatthemovable contact tracks accurately and maintains vacuum integrity withinthe bottle.Figure 1 - Typical Vacuum Bottle Cross SectionContactor Operation The standard electrically held contactor consists of three vacuum bottles thatare operated by anelectromagnet assembly through a mechanical linkage(Figure 2 on page 10).Electromechanical Relay Controlled

• When the control circuit is energized, current flows through both aclosing coil and hold-in coil, which creates an electromagnet.

• This electromagnet pulls the armature plate towards the coil core, whichalso rotates the actuator shaft.

• The actuator plate, in turn, pushes the insulator and vacuum bottlemovable shaft up, which closes the contacts inside the vacuum bottle.

• The control circuit economizing/auxiliary contacts, which are on theleft side of the contactor, change state once the contactor fully closes.

• The current that is energizing the closing coil is then switched off. Thecontactor remains closed by the hold-in coil only.

• The contactor is opened by de-energizing the hold-in coil.

The mechanical latch version of the contactor operates similarly with thefollowing exceptions:

• Both coils are de-energized upon closing of the contactor, and thearmature plate is held in the closed position by a spring-loaded latchingmechanism.

• The contactor is opened by energizing a trip coil that pulls the latchaway from the armature, or by engaging a manual trip mechanism (seeFigure 3 on page 10). The manual trip mechanism is operated by pushbutton on the front of the medium voltagedoor.External control relays and a rectification circuit are used to control thestandard DC closing and hold-in coils on the contactor. Only use RockwellAutomation approved control components to achieve optimal performance.IntelliVAC ControlledThe electrically heldvacuumcontactor operates as follows:

• When the IntelliVAC or IntelliVAC Plus control modules receive a closecommand, the contactor coil is energized, the current creates anelectromagnet in the coil.

• The electromagnet pulls the armature plate towards the coil core, whichrotates the shaft and causes the actuator plate to move upwards.

• As the actuator plate moves, it pushes the insulator and movable shaftup, which closes the contacts in the vacuum bottle.

• The IntelliVAC or IntelliVAC Plus control modules supply the closecurrent to the coil for approximately 200 ms. Afterward, the coil currentis reduced to a lower hold-in value.

• When the IntelliVAC and IntelliVAC Plus control modules remove theclose command, the coil is de-energized, which opens the contactor.The mechanical latch contactor operates similarly as the electrically heldversion with a few exceptions:

• Once the contactor is closed, a spring-loaded mechanism moves a rolleragainst the armature plate to hold it against the electromagnetic core.

• The contactor can be opened electrically by energizing a trip coil (viaIntelliVAC and IntelliVAC Plus open output) which pulls the latchaway from the armature. The contactor can also be opened using a pushbutton that is mounted on the power cell door thatmechanicallyreleases the contactor.