Document 06pvG8GmY0v38a8ga664eO3ad

GENERAL INFORMATION 13 WIRING DIAGRAMS A symbolic representation of operation and function of control devices. Panel Diagram--wiring, panel and pilot device lay out-actual position of de vices--power line bold and control lines light--circuit symbols show basic construc tion details. REDUCED VOLTAGE AND FULL VOLTAGE Most applications suitable for full voltage starting--full motor inrush current during starting--maximum acceler ation--simplest control construction--lowest control cost --easy maintenance--motor connected directly to power supply. Restrictions in power supply capacity or machine design may require reduced voltage starting--motor connected to power supply at voltage lower than supply voltage-- requires use of primary resistance, reactance or use of auto-transformer--special motor designs such as part winding and wye-delta considered as reduced voltage starting. CONTACTORS *R* AN0"S* Line Diagram--con nection representa tion but not wiring configuration -- se quence and function of devices but not location -- power lines bold and con trol lines light--sym bols do not represent physical construction of device. NON-REVERSING AND REVERSING Non-reversing--single contactor and overload relay for each speed--single direction. Reversing--two contactors and one overload relay for. each speed--reversals of direction by internal connection of line leads to contactors--contactors electrically and mechanically interlocked to prevent line shorts and energization of both contactor coils simultaneously. JOGGING, INCHING, PLUGGING SERVICE Jogging or inching--momentary operation of driven machine for small movement or positioning--requires non-maintained operator and electrical control circuitcontrol subject to motor inrush current on each jog or inch cycle--contactor derated where service requirement demands more than 5 cycles per minute. Plugging--plugging stop or plugging reverse--reverse power supplied to motor--motor generates brakingcontactors subjected to motor inrush during plugging-- requires reversing contactors--contactor derated for plugging service. ACCESSORIES, MASTER OR PILOT SWITCHES Primarily used with magnetic control--directs function of starter or controller--provide non-automatic, semi automatic or automatic operating function--local or remote connection to control--device may be personally operated or respond to specified pre-determined condi tions--usually enclosed--ampere rated--cover pushbut tons, limit, foot and float switches, brakes, pressure and temperature switches, relays and timers. SENSING OR SIGNALING DEVICES Direct magnetic control functions--differ from master or pilot devices as they monitor and compare specific cir cuit conditions and respond in predetermined selected manner--may require original initiation from a master switch--provide for automatic control--devices such as resistor and transistor sensitive relays, proximity limit switches etc. REMOTE AND LOCAL CONTROL Local Control--Controlling or sensing device, master switch or pilot device initiating operation located in same enclosure as directed electric controller. Remote Control--controlling devices located at some other point than directed electric controller--may have more than one operating point with control devices connected in parallel or in series depending on operat ing sequence required. TWO AND THREE WIRE CONTROL Two Wire--automatic restarting--maintained contact master switch--(example, selector switch)--low voltage release (LVR)--two wires from pilot device or master switch to controller--disconnects motor from power supply on power failure--automatically restarts motor on resumption of power--operation from only one loca tion unless latched relaying used. Three Wire--non-automatic restarting--momentary con tact master switch (example, start-stop pushbuttons)-- low voltage protection (LVP)--three wires from pilot device or master switch to controller--disconnects motor from power supply on power failure--control remains disconnected when power restored--to maintain oper ation in running condition control requires auxiliary contact (also called holding circuit interlock)--requires personal operation by operator to initiate control operation. ro-iirS) m O cz c<oG*h 5<0 ^--I 0500 mm m rO -O "O cco=552-s<* go ^ go v 50 GO si So O>5** 2 5(--0i oo m-n mzj--I 3* > 3= m r-- m 50 GO GO O 35>0 O 50 > o CUTLER'HAMMER 13