ABB KF Manuals

A »11 ABB Power T&D Company Inc. Relay Division Coral Springs, FL 33065 Instruction Leaflet I.L. 41-503N Type KF Underfrequency Relay Effective July 1980 Supersedes I.L. 41-503M dated May 1975 ^ Denotes change since previous issue CAUTION: Before putting relays into service, re- move all blocking which may have been inserted for the purpose of securing the parts during ship- ment, make sure that all movings parts operate freely, inspect the contacts to see that they are clean and close properly and operate the relay to check the settings and electrical connections. necessary, without having to remove the magnetic core from the frame. The elec- tromagnet has four coils mounted on the four poles. The coils mounted diametrically op- posite each other are connected in series. The locating pins of the electromagnet are used to accurately position the lower pin bearing, which is mounted on the frame, with respect to the upper pin bearing which is threaded into the bridge. The electromagnet is secured to the frame by four mounting screws. APPLICATION The type KF relay is a high-speed under- frequency relay which provides rapid sensing of system overload so that excessive load can be shed. It is particularly suitable for relatively isolated areas where a severe overload (i.e., more than 50%) could occur due to a tie-line trip. G The moving element assembly consists of a spiral spring, contact carrying member, and an aluminum cylinder assembled to a molded hub which holds the shaft. The shaft has removable top and bottom jewel bearings. The shaft rides between the bottom pin bearing and the upper pin bearing with the cylinder rotating in an air gap formed by the electromagnet and the magnetic core. The stops for the moving ele- ment contact arm are an integral part of the bridge. CONSTRUCTION & OPERATION The relay consists of an induction cylinder unit, frequency sensitive components, indicating contac- tor switch, and auxiliary time delay unit (T). The principal parts of the relay can be seen in Figure 1. A. Induction Cylinder Unit The induction cylinder unit is a product type unit operating on the interaction between the fluxes that are produced on the four poles. Mechanically, the induction unit is composed of four basic components; a die cast aluminum frame, an electromagnet, moving element assembly and a molded bridge. The frame serves as a mounting structure for the magnetic core. The magnetic core which houses the lower pin bearing is secured to the frame by a locking nut. The bearing can be replaced, if The bridge is secured to the electromagnet and frame by two mounting screws. In addition to holding the upper pin bearing, the bridge is used for mounting the adjustable stationary contact housing. The stationary contact hous- ing is held in position by a spring type clamp. The spring adjuster is located on the underside of the bridge and is attached to the moving contact arm by a spiral spring. The spring ad- juster is also held in place by a spring type clamp. With the contacts closed, the electrical connection is made through the stationary con- All possible contingencies which may arise during installation, operation, or maintenance, and all details and variations of this equipment do not purport to be covered by these instructions. If further information is desired by purchaser regarding this particular installation, operation or maintenance of this equipment, the local Asea Brown Boveri representative should be contacted. Courtesy of NationalSwitchgear.com to STATIC TIMING CIRCUIT 'WlV.VlY.A <,.•••:... '.v' v.',.',.:. c: n- i-'ir.-S s 3 , s ! r m TELEPHONE RELAY ^ CVUNDI UNIT I . . 9 *'°~*“* FREQUENCY ADJUSTING SCREWS Ss*. i m i l 'l l* h % < < : •; f- i ' mi ADJUSTMENT m TJ L ».. i u SB ss ? . ~ . : Rear V i e w F r o n t V i e w Fig. 1. Type KF Relay for 60 Hertz Without Case. (Front & Rear View) Courtesy of NationalSwitchgear.com I.L.41-503N INTERNAL SCHEMATIC INTERNAL SCHEMATIC — 7i s* 7© CYLINDER UNIT TCLEnOCE RELAY CYLINDER UNIT c cs T i RS If *4» FREQUENCY ADJUST REACTOR FREQUENCY ANJW5T REACTOR -2L TTA -LT ± " y LJ a ! 5? a C=D tcs ‘5 Dor ik ~ ^riyffiTVi I wn J i H ' i if: SEE TABLE 1 # L Time Delay K F with DC Timer — 6 to 30 cycles (ad- justable) KF with AC Timer — 6 to 30 cycles (ad- justable) KF with AC Timer — 6 cycles (non-adjustable) 7 INDICATING CONTACTOR SNITCH £ *CEEH ICS. CYLINDER UNIT Tlrrrrt11^ ran i 6 6 9 3” 9-'9"9 6 6' RED HANDLE TEST SWITCH 6 6 £ <^ > 6 9 9 9 ! © © © © © ©« © © ©sr 6" TERMINAL TABLE 1 FRCWT view " ELAT IATIM LEAD «£$!$. VALUE TUP P0S. V01TACE 200 A 41 , 41/ 125 ITS 15 0 0ft. Trip Circuit Constants Indicating Contactor Switch— 0.2 amp tap 6.5 ohms dc resistance 2.0 amp tap 0.15 ohms dc resistance Energy Requirements Sub. 9 849A318 © Fig. 4. Internal Schematic ot Type KF Relay with DC Operated Adjustable Auxiliary Time Delay Unit. 3. DC Operation This telephone relay in conjunction with a static timing circuit provides adjustable time delays (i.e. 6 cycles to 30 cycles) on pickup when the KF relay contacts close. The contacts of the auxiliary time delay unit are connected in the trip circuit. Voltage Timer Condition Burden Relay Type AC 60 Hertz KF with DCTimer N/A 14.7VA 120 KF with Adjustable AC Timer Energized De-energized 29 ,4VA 14.7VA 120 KF with Non- Adjustable AC Timer Energized De-energized 20.4VA 14.7VA CHARACTERISTICS 120 The KF relay operates to close its contacts when the applied source frequency is below a preset value. The operating characteristic curves for the various auxiliary time delay settings for © Frequency changing frequency conditions is shown in Figure SETTINGS The relay is set for trip frequency by means of the reactor adjusting screws. The relays are calibrated to trip at V2 hertz below rated frequency unless otherwise specified. Turning either of the adjusting screws in a clockwise direction decreases the frequency at which the relay trips. The rate of change of frequency per second versus hertz below trip frequency at contact closure is shown in Figure 5 for various time delays. 5. Rating The type KF underfrequency relay is rated 120 volts at 60 hertz, or 120 volts at 50 hertz. The ad- justable range of frequency is 55 to 59.5 hertz for the 60 hertz relay and 44 to 49.5 hertz for the 50 hertz relay. 4 Courtesy of NationalSwitchgear.com