According to the invention, the actuator 110 is in mechanical communication with the removable conduction. The intent of periodic maintenance is to keep the system operating at an acceptable level of service to the public. Contactors electromechanical relays electronics textbook. Type s contactors and startes 3 manual triptotest allows a quick test of the mechanical and electrical operation of the overload relay. Typical electrical drawing symbols and conventions. Contactors, class 8910 types dp and dpa definite purpose contactors are ideal for heating, air conditioning, refrigeration, data processing, and food service equipment. Sparkyhelp training services registered electrical contractor rec 27507. En 5011011 1 the national standards applicable in the country where the equipment is. Threephase, 480 volt ac power comes into the three normallyopen contacts at the top of the contactor via screw terminals labeled l1, l2, and l3 the l2 terminal is hidden behind a squareshaped snubber circuit connected across the contactors coil terminals.
Contactors employ two distinct devices for their operation an electric coil solenoid and a set of conductive contactors. Fused control circuit transformer and control relay. The contact part of the contactor includes the power contacts as well as the auxiliary contacts. Ac reversing manual starters and manual motor starting switches. Contactors are used by electrical equipment that is frequently turned off and on opening and closing the circuit. To deactivate, the contactor can be pulled out of the parent device in which its embedded and operating. Starter assembly the assembly and wiring of electromechanical starters is extremely fast and reliable. This video explains the principle of operation of contactors. What we need to look at briefly is the operation of the contactor. The power contacts gains the power for the contactor and the auxiliary contacts is used to bring a loop with the rest of the rest of the devices it. This is to ensure a trouble free operation of the contactor until the next service is required see next section interpreting levels of electrical contact wear. Some of the common reasons are excess current flowing through the contacts. To complement the contactors, thermal overloads are offered for each frame size, available in several setting ranges.
Maintenance manual chapter 9 electrical system maintenance. To indicate static switching control, use the symbols shown in this table, enclosing them in a diamond as shown. H place the device on a support at working height in order to perform the maintenance operation. The basics of contactors contactors are useful in commercial and industrial applications, particularly for controlling large lighting loads and motors. Fundamental relayoperating principles and characteristics 19 singlequantity relays of the electromagneticattraction type here we shall consider plungertype and attractedarmaturetype ac or dc relays that are actuated from either a single current or voltage source. The basics of contactors commercial electric products. When powering the contactor coil, the magnetic circuit and coil form an electromagnet. Pdf control systems books collection free download.
Chapter 9 electrical system maintenance general all electrical systems require periodic maintenance in addition to nonscheduled maintenance caused by unpredictable events such as storms, accidents, and equipment failure. Therefore, the function of the contactor is to switch an electrical circuit on or off. The power contacts gains the power for the contactor and the auxiliary contacts is used to bring a loop with the rest of the rest of the devices it is attached to. The invention relates to an electrical contactor and to the associated contactor closure control method.
Normal failure modes include contact sticking and improper operation. Electrical faults l phase to phase l phase to ground l phase to phase to phase l phase to phase to phase to ground. The sc series contactors have such options as additional auxiliary contact blocks and operation counter unit with snapon fittings, and coil surge suppressors. However, like any other device, they are not infallible. Features quick connect terminals and binder head screws allow for easy.
By following a relatively basic stepbystep process, you can connect an electrical contactor in a matter of minutes. Lowvoltage contactor is an electrically controlled switch used for switching an electrical power circuit, similar to a relay except with higher current ratings. A contactor is controlled by a circuit which has a much lower power level than the switched circuit. A reversing contactor is an assembly of two contactors one for each direction joined by a mechanical andor electrical interlock to ensure only one contactor is energized at a time.
Microsoft powerpoint electrical protection module 4. Battery contactor power in from battery power out to control unit or main bus wire to vp100200 control unit j5 pin 5 or to master switch. Dc contactors trombetta powerseal family solid state. Ppt contactors powerpoint presentation free to view.
Cat th360b telehandler operator and maintanence manual. Improved contact materials and structure double the electrical life compared with existing contactors 2 million operations. If you wire this side to the battery the contactor will not work. They are designed to meet demanding requirements, based on comprehensive application experience. Manual guidelines for contactor inspection and maintenance. It does not disturb the contactor operation and can be adapted to almost all types of electrical contactor. Current adjustment dial lastminute changes to match relay to motor.
Find all the information for devices on the official hager website. Due to a dynamic magnetic circuit that interacts with dynamic contacts and control contacts. Contactors are used in applications ranging from the light switch to the most complex, automated industrial equipment. Auxiliary contacts allow additional operations to take place when the contactor is energized. Motor starters, contactors, and relays, like any switching device, have a finite life. Operating coils of contactors and starters are activated by control devices such as pushbuttons, limit switches, and pressure switches. A contactor can stand on its own as a power control device, or as part of a starter.
Comatreleco industrial relays feature manual operation. Current capacity varies by family with inrush capacities of 800a and continuous carry capacities up to 225a. A contactor joins 2 poles together, without a common circuit between them, while a. Citi contactors and motor starters provide trouble free switching and maximum protection for costly motors and other electrical equipment. Overloading of the circuit can be prevented by adding an thermal overload relay. In the last post i took the control circuit through to the contactor coil for the purpose of fault finding. Medium voltage distribution motor control center up to 7,2 kv. The coil solenoid is controlled by a separate control voltage. A contactor is typically controlled by a circuit which has a much lower power level than the switched circuit, such as a 24volt coil electromagnet controlling a 230volt motor switch. One of the things that tend to dismay the novice is the great variation in appearance and types of relays, but actually. Simply closing such a switch to send threephase power to the motor will cause it to start up, while opening the threepole switch will cut power to. Static switching control is a method of switching electrical circuits without the use of contacts, primarily by solid state devices.
A wiring diagram is a streamlined traditional photographic representation of an electrical circuit. All the relays that we shall consider operate in response to one or mo re electrical quantities. Contactors are electrically controlled switching devices used for switching of electrical circuits. The electrodynamic forces during a short circuit can mechanically damage the contactor.
Contactors have 1, 2, 3 or more sets of contacts and are pulled in when an electromagnetic coil is energized. How to size a contactor for any application springer. Shown here is a contactor for a threephase electric motor, installed on a panel as part of an electrical control system at a municipal water treatment plant. That is, the magnetic circuit is sucked into the magnetic circuit. It shows the parts of the circuit as simplified forms, and the power and signal links between the tools. Contactors are typically built for and used in 3phase applications where a relay is more commonly used in single phase applications. Modification can be made quickly and easily on site. F integrated freewheeling diode and series diode e. At the same time observations can be made to judge if the contactor operates well in the application and that no signs of abnormal wear or damages are present on the contacts. Contactors are used by electrical equipment that is frequently turned off and on with the opening and closing of a circuit. The product offering starts with mini contactors in a compact 12 amp frame.
The components are compact, easy to install and extremely reliable. Rc suppressors freewheel diode suppressors varistor suppressors on the contactor relay dila the coil connection a1 is at the top and a2 at the bottom. Purpose of protection system l minimize damage l leave unaffected equipment inservice. Guidelines for contactor inspection and maintenance abb aafline. In most cases, the contactor does not simply wear out from normal use. Caterpillar 246c, 256c, 262c, 272c, 277c, 287c, 297c service learning pdf. To start up and shut down a threephase ac induction motor, any threepole switch with a suitable current rating will suffice. In this lesson well introduce the contactor, the principal interaction point between the control and power aspect of an electrically controlled system using motors. On the top positioned terminals a1a2 of the contactor diler the following accessories are connected to limit the relay coil switch off breaking voltage peaks. Medium voltage distribution pix schneider electric.
Contactors are typically used to switch heavier loads than relays and have more powerful closing force than relays and therefore less contact bounce. The function of the contactor is to make and break all power supply lines running to a load or to repeatedly establish and. A free powerpoint ppt presentation displayed as a flash slide show on id. When this post is grounded the contactor is closed. Wo2006051124a1 electrical contactor and associated. Trombetta dc contactors are a robust and cost effective solution for high current switching up to 48vdc. Allows the relay to operate in both ac or dc without any. Cat 72h pipelayer operation and maintanence manual. Dont assume that all contactor coils operate with a low control voltage. Economic recovery group on april 14, 2020, president donald trump announced the formation of a great american economic revival industry group, a task force with a focus on reopening the u.
Click on the product families below to view details. Rc suppressors freewheel diode suppressors varistor suppressors on the contactor relay dila the coil connection a1. Pdf a new power supply system for ac contactor ridethrough. Commmon reasons for contactor failure electrotechnik. Trip class selector class selectable trip curve for field configuration. A contactor is an electricallycontrolled switch used for switching an electrical power circuit. The contactors can be operated with ac 40 to 60 hz as well as with dc. Reset actuator used to manually reset the relay after a trip event. Pdf this paper describes a new power supply system that enables an ac contactor to ride through power grid. Compact 1 and 2pole contactors are available, as well as fulls ize devices with 2, 3, or 4 poles. High current can be either due to overload or due to shortcircuit.
1382 92 608 487 49 233 925 322 569 395 1359 1355 1275 330 788 221 761 1155 368 303 1408 439 622 425 144 151 269 1232 415 1421 560 259 1208 434 351 1491 730