India is normally supplied with a 220V current, but the voltage can from 150V to 280V. This is problematic since the VSAT units provided by some vendores are designed to operate on 220V. Stabilization of the voltage supplied by the power lines is critical since too much voltage will damage the equipment and too little voltage will cut the connection to the Internet.

To provide a stable voltage of 220V to the VSAT units, an offline Constant Voltage Transformer (CVT) and an Uninterrupted Power Supply unit have to be used. Both units are needed since the power supply has a tendency to cut off at any given time of the day, necessitating the use of a back-up generator. Spikes in voltage occur quite often. The CVT unit has a range of 150V to 260V and is usually sufficient on its own to smooth the current, but since it is offline, there is a short delay between the power spikes and the unit kicks in. Although measured in milliseconds, this delay is enough to interrupt the connection and shut down the VSAT unit.


A Typical VSAT Configuration

In order to overcome this problem, a UPS has to be used in conjunction with the CVT. The range of the UPS is much smaller, about 40V either way from the mean, but it has the benefit of being continuously online. Therefore, when changes in voltage occur or the voltage cuts off, it can continue supplying enough electricity to the unit without any delay. The two units are connected to the VSAT in the following manner: Electrical Supply » CVT » UPS » VSAT. The same system is used to power the computer units as well.

Emerson Network Power has the solutions for your VSAT setup