SERVICE TRAINING ® DCA GENERATOR TROUBLESHOOTING GUIDE ○ TROUBLESHOOTING ○ Manual No.
CALIFORNIA Proposition 65 Warning: Engine exhaust and some of its constituents, and some dust created by power sanding, sawing, grinding, drilling and other construction activities contains chemicals known to the State of California to cause cancer, birth defects and other reproductive harm. Some examples of these chemicals are: Lead and lead-based paint. Crystalline silica from bricks. Cement and other masonry products. Arsenic and chromium from chemically treated lumber.
IMPORTANT! Read the operator's manual for safety instructions before you attempt to troubleshoot. Use extreme caution when troubleshooting power equipment. Never start or run power equipment inside a closed area, breathing exhaust fumes can kill. Basically, a tool is an object that enables you to take advantage of the laws of physics and mechanics in such a way that you can seriously injure yourself.
SAFETY PLEASE REMEMBER SAFETY FIRST!!!!!!!!!!!!! This troubleshooting guide emphasizes safety precautions necessary during operation and testing. Safety precautions should be followed at all times when operating, maintaining and testing power equipment. Failure to read and understand safety precautions and warnings could result in injury to yourself and others. PLEASE READ ALL SAFETY PRECAUSIONS AND WARNINGS LISTED IN THE SECTION MARKED SAFETY BEFORE OPERATING, SERVICNG OR TESTING THIS EQUIPMENT.
CONTENTS Troubleshooting Charts ………………………………………………………………………….…….6 o No Voltage – Residual Voltage Only…………..……………………………………………..7 o No Voltage…………..…………………………………………………………………………..8 o Low Voltage – No Load …………..………………….………………………………………..9 o Low Voltage – On Load …………..………………….……………………………………….10 o High Voltage …………..………………….……………………………………………...…….11 o Voltage Unstable – No Load …………..………………….………………………………….12 o Voltage Unbalance …...………………….……………………………………………...…….
TROUBLESHOOTING CHARTS This manual is intended to suggest a systematic approach to locating and correcting generator malfunctions. The steps have been arranged in an attempt to do the easy checks first and prevent further damage when troubleshooting a disabled machine. The first step of troubleshooting is to gather as much information as is possible from operating personnel and individuals present during the failure.
NO VOLTAGE – RESIDUAL VOLTAGE ONLY Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
NO VOLTAGE 8 Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
LOW VOLTAGE – NO LOAD Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
LOW VOLTAGE – ON LOAD 10 Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
HIGH VOLTAGE Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
VOLTAGE UNSTABLE – NO LOAD 12 Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
VOLTAGE UNBALANCE Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
TESTING EXCITER FIELD RESISTANCE 14 Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
TESTING VOLTAGE INPUT TO AVR OPEN DELTA WINDINGS Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
MANUAL EXCITATION TEST USING A BATTERY & VOLTAGE BALANCE TEST 16 Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
ROTATING RECTIFIER TEST Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
TESTING ROTATING RECTIFIER USING A 12V DC TEST LIGHT 18 Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
EXCITER FIELD INSULATION TEST Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
STATOR INSULATION TEST 20 Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
TEST STATOR WINDINGS Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
TEST MAIN ROTOR FIELD 22 Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
TEST EXCITER ARMATURE Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
TABLE OF GENERATOR DATA 24 Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
AUTOMATIC VOLTAGE REGULATOR There are four connectors that attach to the AVR and two wires to the AVR terminals. The AVR also has three potentiometers, only one is for course adjustment the other two should NOT be touched. IMORTANT: There is no procedure for directly testing the AVR, use process of elimination. 8 amp fuse MQ part # 6978K753 Open delta leads and excitation leads connect to the AVR on this connector.
GEN-SET DATA The chart below can be used as a reference guide for measuring resistance on the Gen-Set CROSS REFERENCE CHART RESISTANCE MEASURED IN OHMS Ω Main Armature Generator Gen-Set Model # Model # DCA-25SSAI AVR Inputs Main Exciter Armature Field Armature Field AC Outputs DC+ DC- UVW J+ K- 0.14 2 0.47 51 - A-B Field 2 B-C C-D D-A 51 0.9 2.7 DCA-25SSI DB-0281 0.155 1.09 0.16 14 - 0.83 2.5 DCA-25SSI2 DF-0270 0.124 4 0.3 17.6 - 0.9 2.
WYE DIAGRAMS Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
VOLTAGE SELECTOR SWITCH The internal connections between terminals on the voltage selector switch are indicated by an used are external *metal and **wire jumper connectors, see page 20 for jumper locations.
VOLTAGE SELECTOR SWITCH * Metal Jumper Connections o o o o DCA-25SSI DCA-45SSI DCA-70SSI DCA-100SSV o o DCA-150SSV DCA-150USJ o o DCA-25USI DCA-45USI DCA-70USI DCA-85USJ o o ** Wire Jumper Connections o o o DCA-25SSI DCA-45SSI DCA-70SSI o DCA-100SSV o o DCA-25USI DCA-45USI DCA-150USJ o o DCA-150SSV o o o DCA-70USI DCA-85USJ DCA-125USJ Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.
GENERATOR GLOSSARY Ammeter - An instrument that measures electric current in amperes. Amperage (Amps) - The strength of a electrical current measured in amperes. Armature - That part of a generator or of an electric motor in which a current is induced by a magnetic field. The armature usually consists of a series of coils or groups of insulated conductors surrounding a core of iron. See page 8 for more information.
GENERATOR GLOSSARY Phase Single Phase Power (typically 120V AC or 230V AC depending on the country) is carried between two wires: live and neutral and sometimes a third ground wire for safety. The frequency of AC voltage is 50 or 60 Hz depending on the country. Single-phase power is used in very many applications, for example to power all typical home electrical appliances you use single-phase power from a normal electrical outlet at home.
Corporate Headquarters • Multiquip Inc. 18910 Wilmington Ave. Carson, Ca. 90746 32 Multiquip Inc. ◦ DCA Generators Troubleshooting Guide ◦ Manual No.