GENERATOR

1 GENERATOR280 430 FrameInstallation, Operation,and Maintenance ManualMarathon Electric Mfg. REGAL-BELOIT Box 8003 Wausau, WI 54402-8003 Phone: (715) 675 3359 Fax:(715) 675 and Storage2 Principles of Operation3 - 4 Installation4 - 6 Wiring Connections6 - 9 Operation9 - 10 Maintenance11 - 12 Testing12 - 13 Service13 - 15 Troubleshooting15 - 18 Specifications19 Parts List & Recommended Spare Parts20 - 22 SAFETYPLEASE REMEMBER SAFETY you are not sure ofthe instructions or procedures contained herein, seek qualified help before service manual emphasizes the safety precautions necessary during the installation, operation.

2 And maintenance of your MagnaPLUS GENERATOR . Each section ofthis manual has caution and warning messages. These messages are for your safety, and the safety of the equipmentinvolved. If any of these cautions or warnings are not readily understood, seek clarification from qualified personnel before any service work is done, disconnect all powersources and lock out all controls to prevent an unexpectedstart up of the GENERATOR set driver. Proper grounding (earthing) of the GENERATOR frame and distribution system incompliance with local and national electrical codes and specific site requirements must be provided.

3 These safetyprecautions are necessary to prevent potential serious personal injury, or even hazards associated with lifting or moving yourMagnaPLUS GENERATOR are pointed out in the installation andmaintenance sections. Incorrect lifting or moving can result inpersonal injury or damage to the to start up of the unit ensure that all GENERATOR leads areproperly connected to the GENERATOR link board located insidethe connection box. Always assume that there will be voltagepresent at the GENERATOR terminals whenever the GENERATOR 'sshaft is rotating, and proceed accordingly.

4 Residual voltage ispresent at the GENERATOR terminals and at the automatic voltage regulator panel connections even with the regulatorfuse removed. Caution must be exercised, or serious injury ordeath can manual is not intended to be a substitute for properlytrained personnel. Installation and repairs should only beattempted by qualified, trained people. The cautions andwarnings point out known conditions and situations that arepotentially hazardous. Each installation may well create itsown set of in doubt, ask.

5 Questions are much easier to handlethan mistakes caused by a misunderstanding of the information presented in this AND STORAGE RECEIVING AND STORAGEUpon receipt of the GENERATOR , it is recommended that it becarefully examined for possible shipping damage. The GENERATOR was given to the freight carrier in good condition;thus, the carrier is responsible for the product from the factory dock to the destination. Any damage should be notedon the freight bill before accepting the shipment.

6 Any claimsfor damage must be promptly filed with the delivering AND HANDLINGC arefully read all instruction tags shipped with the unit. Whenlifting, attach an overhead crane to the lifting lug(s) on thegenerator frame. Apply lifting forces in a vertical transporting single bearing generators, the GENERATOR srotor must be adequately supported to prevent LIFTING LUG(S) ON THE GENERATOR AREDESIGNED TO SUPPORT THE GENERATOR NOT LIFT A COMPLETE GENERATOR AND DRIVER ASSEMBLY BY MEANS OF LIFTING LUG(S)ON THE GENERATOR .

7 PERSONAL INJURY OREQUIPMENT DAMAGE MAY the event that the GENERATOR is not immediately installed onits prime mover, it is recommended that the unit be storedindoors in a clean, dry area which is not subject to rapidchanges in temperature and humidity. If the GENERATOR isstored for a long period of time, the GENERATOR should be tested, cleaned and dried as required before being put intoservice. See the maintenance section of this manual for further information. If the unit has been stored in an areawhere it has been subject to vibration, it is recommended thatthe bearing(s) be inspected and replaced as OF OPERATIONFIGURE 1 -- MagnaPLUS Circuit DiagramFIGURE 2 -- Typical MagnaPLUS Layout Diagram PRINCIPLE OF OPERATIONM agnaPLUS generators are brushless, self excited, externally voltage regulated, synchronous AC GENERATOR .

8 Thegenerator is made up of six major components: main stator(armature), main rotor (field), exciter stator (field), exciterrotor (armature), rectifier assembly, and voltage regulator. Inunderstanding the above terminology, note the following:stators are stationary, rotors rotate, a field is a DC electricalinput, and an armature is an AC electrical output. These system components are electrically interconnected as shownin Figure 1 and physically located as shown in Figure GENERATOR s exciter consists of a stationary field and arotating armature.

9 The stationary field (exciter stator) isdesigned to be the primary source of the GENERATOR s residualmagnetism. This residual magnetism allows the exciter rotor(armature) to produce AC voltage even when the exciter stator (field) is not powered. This AC voltage is rectified to DCby the rotating rectifier assembly and fed directly to the mainrotor (field). As the GENERATOR shaft continues to rotate, themain rotor (field) induces a voltage into the GENERATOR 's mainstator (armature). At rated speed, the main stator s voltageproduced by the residual magnetism of the exciter allows theautomatic voltage regulator to function.

10 The regulator provides voltage to the exciter field resulting in a build-up of GENERATOR terminal voltage. This system of using residualmagnetism eliminates the need for a special field flashing circuit in the regulator. After the GENERATOR has established theinitial residual voltage, the regulator provides a controlled DCfield voltage to the exciter stator resulting in a controlled GENERATOR terminal RegulationIn the standard configuration (shunt excited), the automaticvoltage regulator receives both its input power and voltagesensing from the GENERATOR 's output terminals (See Figure 1).