Assuming your UPS is in good health there are two reasons for this:
1. The genrator electricity and normal electricity is not the same. Generated electricity is more rough with huge fluctuations than the supplied electricity. If your UPS is really a good one it senses this rough load and cuts of the input electricity. But this will not happen in latest technology gensets as they have special equipments to smoothen the output power - but only very latest and technically advanced sets have this.
2. Normally many of the electrical appliances take more load to start than during the continuous running time. So the generated load during the initial few minutes would be less than sufficient if you are running too many appliances. This could also be a reason for the UPS to cut of the inpur power. Read the following to understand better:
"Electrical loads such as incandescent lamps and hot plates require the same wattage to start as is needed to maintain use.
Loads such as fluorescent lamps require 2 to 2 times the indicated wattage during start-up. Loads for mercury lamps require 2 to 3 times the indicated wattage during start-up.
Electrical motors require a large starting current. Power requirements depend on the type of motor and its use. Once enough "surge" is attained to start the motor, the appliance will require only 50% to 30% of the wattage to continue running.
Most electrical tools require 2 to 3 times their wattage for running under load during use. (For example, a 9,000 watt generator can power a 3,200 to 7,000 watt electrical tool.)
Loads such as submersible pumps, air conditioners and air compressors require a very large force to start. They need 3 to 5 times the normal running wattage in order to start. (For example, a 5,000 watt generator would only be able to drive a 1,800 to 3,100 watt pump.) "
Usually it is not advisable to run sensitive electronic items especially computers in generated power - better to have a long stand by UPS. |