MAGNAPLUS® GENERATOR 280–430 Frame Installation, Operation, and Maintenance Manual Marathon Electric Mfg. Corp. A Subsidiary of Regal-Beloit Corp. P.O. Box 8003 Wausau, WI 54402-8003 Phone: (715) 675 3359 Fax: (715) 675 8026 www.marathonelectric.
CONTENTS Safety Receiving and Storage Principles of Operation Installation Wiring Connections Operation Maintenance Testing Service Troubleshooting Specifications Parts List & Recommended Spare Parts When in doubt, ask. Questions are much easier to handle than mistakes caused by a misunderstanding of the information presented in this manual.
PRINCIPLES OF OPERATION PMG (optional) PMG Field (rotor) Rotating Assembly Exciter Field (stator) Exciter Armature (rotor) Main Field (rotor) Main Armature (stator) L1 N S (+) (+) DC (in) DC (in) (-) L2 (-) 3 Phase AC (out) PMG Armature (stator) 3 Phase AC (out) Rotating Rectifier Assembly 3 Phase -- Full Bridge Exciter Field Power (DC out) PMG Input Power (optional) (1 phase, 300/250 hertz) Input Power -- Single Phase (shunt powered regulator) Automatic Voltage Regulator Sensing Input --
horsepower per generator KW in motor starting capability. For specific data contact Marathon Electric. PRINCIPLE OF OPERATION MagnaPLUS generators are a brushless, self excited, externally voltage regulated, synchronous AC generator. The generator is made up of six major components: main stator (armature), main rotor (field), exciter stator (field), exciter rotor (armature), rectifier assembly, and voltage regulator.
driver and the generator's shaft. Aligning the generator and its driver as accurately as possible will reduce vibration, increase bearing life, and ensure minimum coupling wear. It may be necessary to shim the generator feet for proper support and alignment. Secure the feet of the generator with grade 5 or greater bolts through the holes provided in the mounting feet. Consult the coupling manufacturer's instructions for alignment specifications and procedures.
interior of the generator from shavings when drilling or sawing. An approved connector must be used in conjunction with the conduit. To minimize the transmission of vibration, it is essential that flexible conduit be used for all electrical entrance to the generator conduit box. ENVIRONMENTAL CONSIDERATIONS The MagnaPLUS generator is designed for heavy duty industrial applications; however, dirt, moisture, heat and vibration are enemies of rotating electrical machinery.
LOW (PARALLEL) WYE CONNECTION L1 T7 T1 T10 T4 T12 VOLTAGE (LOW WYE) Hz L-L L-N 60 240 139 230 133 220 127 208 120 190 110 50 208 120 200 115 190 110 L-L T5 T9 T2 T6 T11 L3 T3 L2 T8 L-N HIGH (SERIES) DELTA CONNECTION T12 L1 T1 ` T6 L-L T7 T3 L3 VOLTAGE (HIGH DELTA) Hz L-L L-N 60 277 139 240 120 50 240 120 220 110 200 100 T4 T9 T10 T11 T8 T5 L2 T2 L-N LOW (PARALLEL) DELTA CONNECTION L1 T12 T1 T9 T3 L3 T4 T10 T11 VOLTAGE (LOW DELTA) Hz L-L L-N 60 120 NA 110 NA 50 110 NA 100
DOUBLE DELTA -- SINGLE PHASE CONNECTION T3 T5 T6 L2 T11 T9 T2 T1 T8 T12 T4 VOLTAGE (DOUBLE DELTA) Hz L-L L-N 60 240 120 220 110 50 220 110 T7 T10 L1 L-N L-N Note: Single phase KW/KVA ratings are approximately equal to 50% of the generator’s three phase ratings.
DEDICATED SINGLE PHASE CONNECTION HIGH VOLTAGE - SERIES CONNECTED L1 T1 T2 T3 T4 VOLTAGE (DEDICATED) Hz L-L L-N 60 240 120 220 110 50 220 110 200 100 L2 L-N L-N L-L OPERATION PRE-START INSPECTION 8. Review all prime mover prestart-up instructions, and ensure that all recommended steps and procedures have been followed. 9. Remove any masking materials affixed during painting.
6. The purpose of this initial test with the regulator out of the circuit is to detect any wiring mistakes without exposing the unit to undue risk. Check all line to line and line to neutral voltages for balanced voltage. If voltages are balanced, shut down the set and reconnect the regulator. If voltages are unbalanced, shut down the equipment and check for improper wiring. If the problem persists, consult the factory.
or the rotating rectifier assembly. Ensure that RPM is the same as initial test. WARNING 5. Monitor and record insulation resistance with a 500 volt mega-ohm meter. The minimum acceptable reading is 2 mega-ohms. If the reading drops below the minimum, the generator should be cleaned and dried at an authorized service shop. Consult Marathon Electric for more information. THE FOLLOWING TEST MUST BE CONDUCTED BY QUALIFIED ELECTRICAL PERSONNEL.
When the positive test probe is connected to the diode's anode and the negative test probe is connected to the diode's cathode (forward biased), the diode will switch on and conduct electricity (figure 3). This is observed by a low resistance reading when using an ohm meter or the lighting of the bulb when using a battery light continuity tester. Reversing the test leads (reverse biased) will result in the diode switching off and no electricity will be conducted.
clear the locating register on the frame. Lower the shaft extension until the rotor is resting on the main stator core. Continue to pull the bracket free from the bearing. Visually inspect the bearing bore for damage or wear. If worn or damaged, sleeve or replace prior to reassembly. CAUTION: Failure to remove the exciter field leads from the automatic voltage regulator during flashing procedures may destroy the regulator. 2.
430 FRAME 280 / 360 FRAME A - Exciter Rotor Lead, B - Main Rotor Lead, C - Red (+) Suppressor Lead, D - Black (-) Suppressor Lead FIGURE 4: ROTATING RECTIFIER ASSEMBLY RETURNED GOODS The first step of troubleshooting is to gather as much information as is possible from operating personnel and individuals present during the failure. Typical information includes: how long the unit had been operating; what loads were on line; weather conditions; protective equipment that did or did not function.
WARNING HIGH VOLTAGES MAY BE PRESENT AT THE GENERATOR’S TERMINALS WHEN THE UNIT IS RUNNING. SOME ACCESSORY EQUIPMENT SUCH AS SPACE HEATERS MAY BE ENERGIZED FROM AN OUTSIDE POWER SOURCE WHEN THE UNIT IS AT REST. TOOLS, EQUIPMENT, CLOTHING AND YOUR BODY MUST BE KEPT CLEAR OF ROTATING PARTS AND ELECTRICAL CONNECTIONS. SPECIAL PRECAUTIONS MUST BE TAKEN DURING TROUBLESHOOTING SINCE PROTECTIVE COVERS AND SAFETY DEVICES MAY BE REMOVED OR DISABLED TO GAIN ACCESS AND PERFORM TESTS. BE CAREFUL.
GENERATOR PRODUCES LOW VOLTAGE WHEN LOAD APPLIED CAUSE CHECK AND REMEDY Excessive load Reduce load. The load on each leg should be evenly balanced, and rated current should not be exceeded on any leg. Large motor starting or low load power factor Motor starting currents are too large for the generator. When starting multiple motors, sequence the motors and start the largest motors first. Reduce lagging power factor load. Driver speed droop or belt slip Check driver.
GENERATOR BUILDS VOLTAGE FROM STARTUP, THEN GOES TO LOW (RESIDUAL) VOLTAGE CAUSE CHECK AND REMEDY Regulator protective circuit operating Check indicators on regulator. Correct problems and adjust regulator as is required. Refer to regulator manual. GENERATOR IS OVERHEATING CAUSE CHECK AND REMEDY Generator is overloaded Reduce load. Check with ammeter and compare with nameplate rating. Clogged ventilating screens Clean air passages.
SPECIFICATIONS MODEL / FRAME SIZE 281, 282, 283, 284 361, 362, 363 -- three phase 361, 362, 363 -- dedicated single phase 431, 432, 433 -- three phase 431, 432 -- dedicated single phase EXCITER RESISTANCE STATOR ROTOR 23.0 .120 23.5 .120 23.0 .135 20.33 .076 18.0 .105 EXCITER FIELD GENERATOR RESISTANCE NO LOAD VOLTS STATOR* ROTOR 480 V / 60 HZ 281PSL1500 4.20 .400 11.0 281PSL1501 4.15 .400 11.0 281PSL1502 3.20 .439 9.0 282PSL1503 2.00 .470 10.4 282PSL1504 1.51 .512 11.3 282PSL1505 1.00 .575 10.
PARTS LIST – SINGLE BEARING Typical Generator Cross Section Reference Number 1 2 3 4 5 6 7 8 9 10 Note: Part Name Reference Number 11 12 13 14 15 16 17 18 19 20 End Bracket (under end cover 360 & 430 frames) Bearing O-ring (280 frame only) Rectifier Assembly Air Intake Screen (280 frame only) Exciter Rotor Exciter Stator Link Board (terminal block) Conduit Box Generator Frame Part Name Main Stator Main Rotor Rotor Integral Keyway Fan Mounting Adapter (SAE) Shaft Drive Hub Drive Disk (SAE) Exhaust Scree
PARTS LIST – DUAL BEARING Typical Generator Cross Section Reference Number 1 2 3 4 5 6 7 8 9 10 Note: Part Name Reference Number 11 12 13 14 15 16 17 18 19 20 End Bracket (under end cover 360 & 430 frames) Bearing (nondrive end) O-ring (280 frame only) Rectifier Assembly Air Intake Screen (280 frame only) Exciter Rotor Exciter Stator Link Board (terminal block) Conduit Box Generator Frame Part Name Main Stator Main Rotor Rotor Integral Keyway Fan End Bracket (drive end) Bearing (drive end) Shaft Key Ex
