THE FIRST THING TO CONSIDER WHEN CHOOSING A GENERATOR IS THE BRAND AND MANUFACTURING PROCESS. DURING THE TEST RUN, IT IS IMPORTANT TO CHECK WHETHER THE VOLTAGE IS STABLE, WHETHER THE VOLTAGE IS BUILT UP QUICKLY, WHETHER THE FREQUENCY IS STABLE, WHETHER THE VIBRATION IS LARGE OR NOT, THE SIZE AND COLOR OF THE ENGINE EXHAUST, WHETHER THE EXHAUST GAS IS LARGE OR NOT, AND WHETHER THERE ARE ANY OTHER NOISES.  IN ADDITION, THE FOLLOWING EIGHT PITFALLS SHOULD BE NOTED WHEN PURCHASING:1. CONFUSE THE RELATIONSHIP BETWEEN KVA AND KW. EXAGGERATE THE POWER OF KVA AS KW AND SELL IT TO CUSTOMERS. IN FACT, KVA IS THE APPARENT POWER, KW IS THE EFFECTIVE POWER, AND THEIR RELATIONSHIP IS IKVA=0.8KW. IMPORTED UNITS ARE GENERALLY EXPRESSED IN KVA AS A POWER UNIT, WHILE DOMESTIC ELECTRICAL EQUIPMENT IS GENERALLY EXPRESSED IN KW. THEREFORE, WHEN CALCULATING POWER, KVA SHOULD BE CONVERTED TO KW AT A 20% DISCOUNT.2. NOT DISCUSSING THE RELATIONSHIP BETWEEN LONG-TERM (RATED) POWER AND BACKUP POWER, ONLY MENTIONING ONE "POWER" AND SELLING THE BACKUP POWER AS LONG-TERM POWER TO CUSTOMERS. IN FACT, THE BACKUP POWER IS 1.1X LONG LINE POWER. MOREOVER, THE BACKUP POWER CAN ONLY BE USED FOR 1 HOUR IN 12 HOURS OF CONTINUOUS OPERATION.  3. THE POWER OF THE DIESEL ENGINE IS CONFIGURED TO BE THE SAME AS THAT OF THE GENERATOR IN ORDER TO REDUCE COSTS. IN FACT, THE INDUSTRY GENERALLY STIPULATES THAT DIESEL ENGINE POWER SHOULD BE GREATER THAN OR EQUAL TO 10% OF GENERATOR POWER DUE TO MECHANICAL LOSSES. EVEN WORSE, SOME MISTAKENLY REPORT THE HORSEPOWER OF DIESEL ENGINES AS KILOWATTS TO USERS, AND USE DIESEL ENGINES WITH LESS POWER THAN THE GENERATOR TO CONFIGURE THE UNIT, COMMONLY KNOWN AS "SMALL HORSES PULLING BIG CARS", RESULTING IN REDUCED UNIT LIFE, FREQUENT MAINTENANCE, AND HIGH USAGE COSTS.  4. SOME PEOPLE SELL REFURBISHED SECOND-HAND PHONES TO CUSTOMERS AS BRAND NEW PHONES, WHILE OTHERS EQUIP REFURBISHED DIESEL ENGINES WITH BRAND NEW GENERATORS AND CONTROL CABINETS, MAKING IT DIFFICULT FOR NON PROFESSIONAL USERS TO DISTINGUISH BETWEEN NEW AND OLD PHONES.  5. ONLY REPORT THE BRAND OF DIESEL ENGINE OR GENERATOR, WITHOUT REPORTING THE PLACE OF ORIGIN OR UNIT BRAND. IN FACT, NO DIESEL GENERATOR SET CAN BE INDEPENDENTLY COMPLETED BY A SINGLE ENTERPRISE. CUSTOMERS SHOULD HAVE A COMPREHENSIVE UNDERSTANDING OF THE MANUFACTURERS AND BRANDS OF THE DIESEL ENGINE, GENERATOR, AND CONTROL CABINET OF THE UNIT IN ORDER TO EVALUATE ITS OVERALL GRADE.  6. SELL UNITS WITHOUT PROTECTIVE FUNCTIONS (COMMONLY KNOWN AS FOUR PROTECTIONS) TO CUSTOMERS AS FULLY PROTECTED UNITS. SOME EVEN SELL UNITS WITH INCOMPLETE INSTRUMENTS AND NO AIR SWITCHES TO CUSTOMERS. IN FACT, IT IS GENERALLY STIPULATED IN THE INDUSTRY THAT UNITS ABOVE 10KW MUST BE EQUIPPED WITH FULL INSTRUMENTS (COMMONLY KNOWN AS FIVE METERS) AND AIR SWITCHES; LARGE SCALE UNITS AND AUTOMATED UNITS MUST HAVE SELF FOUR PROTECTION FUNCTIONS.  7. NOT TALKING ABOUT THE BRAND GRADE AND CONTROL SYSTEM CONFIGURATION OF DIESEL ENGINES AND GENERATORS, NOT TALKING ABOUT AFTER-SALES SERVICE, JUST TALKING ABOUT PRICE AND DELIVERY TIME. SOME ALSO USE NON POWER PLANT SPECIFIC OIL ENGINES, SUCH AS MARINE DIESEL ENGINES AND VEHICLE DIESEL ENGINES, FOR GENERATOR SETS. THE QUALITY (VOLTAGE AND FREQUENCY) OF THE TERMINAL PRODUCT OF THE UNIT - ELECTRICITY CANNOT BE GUARANTEED. UNITS WITH TOO LOW PRICES GENERALLY HAVE PROBLEMS, COMMONLY KNOWN AS: ONLY BUYING THE WRONG ONE, NOT SELLING THE WRONG ONE!  8. NOT TO MENTION THE SITUATION OF RANDOM ACCESSORIES, SUCH AS WHETHER TO BRING A MUFFLER, FUEL TANK, FUEL PIPE, WHAT GRADE OF BATTERY TO BRING, WHAT CAPACITY OF BATTERY TO BRING, HOW MANY BATTERIES TO USE, AND SO ON. IN FACT, THESE ATTACHMENTS ARE VERY IMPORTANT AND MUST BE CLEARLY STATED IN THE CONTRACT. SOME EVEN DON'T BRING A WATER TANK FAN AND LET CUSTOMERS CREATE THEIR OWN OPEN WATER TANKS.