HOW TO SELECT A VOLTAGE STABILIZER
While selecting voltage stabilizer there are many factors to pay attention so that we can choose right type and right size.
Voltage correction speed:
High voltage correction speed is desirable. High voltage correction speed will ensure correction in voltage before you load switch off. It should be between 70-200 volt/second.
Wide Input voltage range :
Voltage Stabilizer with wider input voltage range has capacity to correct bigger input voltage range. It generally defined in the form of percentage of input voltage i.e. ±20%, ±25%, ±30% etc.
It is always desirable that regulator should deliver precise output voltage. Generally a good quality stabilizer has ±1% voltage regulation which is acceptable. AVR should precisely meet output regulation as percentage of nominal input supply voltage. Automatic circuit breaker should be provided in regulation circuit.
High efficiency is always desired so that losses in stabilizer should be less. High efficiency also indicated good quality of components in stabilizer especially transformer.
In case of input voltage higher or lower beyond designated voltages then regulator should cut off the output with audible and visual alarm.
Over/Under voltage Protection:
Unit should have overload protection and it should isolate the load connected to it and give audio visual alarm.
Independent phase control:
Three phase unit should have independent control for each phase. This will help fast regulation even at work stabilizer even at 100% unbalance load and 100% unbanace input voltages. Unit with independent phase control can also work in case of non-symmetric mains supply.
It is better to have bypass facility in stabilizer in case stabilizer is serving very critical load. Bypass helps to connect input of regulator directly with its output by bypassing circuitry of voltage regulator. This feature is very useful in case you like to repair or do maintenance of unit without shutdown of load.
Input Line filter:
Input line filter will supress unwanted radio frequency components. Unit should have Input line filter in case it is use for supplying voltages to application with electronic circuits e. g. radio station, TV studio, Datacentre etc.
In case of phase reversal at input voltage stabilizer should isolate load.
Unit which are installed in mountain area where there is high possibility of lightning strokes (which cause high voltage spike input), should have surge suppressor to suppressor high spike of voltage. Sudden high voltage spike also can generate due to inefficient electric power