What is the difference between standby/emergency/maximum and prime/continuous duty applications?
A. Most products have a “maximum” rating, also called standby and emergency rating. This value is the most that a generator can produce under normal conditions although it may still have some peak reserve for surges. The prime or continuous rating is the rating that the equipment should not exceed under normal running on a continuous basis. Even though small portables have both ratings that does not mean that they are designed for continuous use. A prime power generator must be 1800 RPM and liquid cooled. Any air cooled or 3600 RPM generator is a standby generator no matter what other dealers may tell you. Most residential generators are standby rated. You should use a prime rated, 1800 RPM, liquid cooled generator when the number of hours per year will exceed 500 and the use is on a regular basis. If you start the generator many times a year for short periods you may also need a prime power rated generator. You must use a prime power rated generator when the generator is used 24 hours
