Department of EEE BEEE LAB BRAKE TEST ON A D.C. SHUNT MOTOR. DETERMINATION OF PERFORMANCE CHARACTERISTICS.
FIGURE: BRAKE TEST ON DC SHUNT MOTOR Department of EEE BEEE LAB
Department of EEE BEEE LAB EXPERIMENT-1 BRAKE TEST ON DC SHUNT MOTOR AIM: To conduct brake test on a given DC Shunt motor and to determine its performance characteristics. OBJECTIVES: To obtain the performance Characteristics of the given motor. To obtain the efficiency of the given motor at various loads and thus determining the load at which maximum efficiency occurs. OUTCOMES: The ability to operate the given motor by varying loads The ability to understand the load at which maximum efficiency occurs. NAME PLATE DETAILS: S. No. 1. 2. 3. 4. 5. 6. 7. Specifications Power Speed Voltage Current Ambient Temperature Excitation Winding Units Rating KW RPM VOLTS AMPS AMB OC EXC WDG APPARATUS REQUIRED: S. No. Item Description 1. 2. Voltmeter Ammeter 3. Rheostat 4. Tachometer Type Range Quantity MC MC WW WW Digital (0-300) V (0-20) A 6Ω/18A 300Ω/1.7A (0-9999) RPM 1 No 1 No 1 No 1 No 1 No
Department of EEE BEEE LAB OBSERVATION TABLE: S.No. S1 (Kg) S2 (Kg) Line current IL (Amps) Terminal voltage Vt (volts) Speed N (rpm) Torque T [9.81×(S1 ~S2)r] (N-m) Input Power (Pi) Vt × IL (Watts) Where, r = radius of the pulley = 0.15m; s1, s2 = spring balances; Let S1 = Readings on spring balance 1 in Kgf.wt. S2 = Readings on spring balance 2 in Kgf.wt. The net force applied on the brake drum is (S1 – S2) Kgf.Wt. MODEL CALCULATIONS: Vt= Terminal voltage = IL= Load current = N= Speed of the machine = S1, S2 = spring balance readings = r= Radius of the brake drum = Output torque, T 9.81 S1 ~ S 2 r Output power, POUT 2NT Watt 60 Input power, PIN Vt I L Watt %Efficiency, % POUT 100 PIN N mt = = = = Output Power (P0) 2ΠNT 60 (Watt) Efficiency (%) η (P0/Pi )× 100