As already known, these are ballasts designed for installations where, at certain hours of the day, the lighting level can be reduced without considerably decreasing the visibility, but with a considerable energy saving.

Some of the Bi-Power advantages are as follows:

• Energy saving –up to 40%
• Longer working life, voltage is not decreasing and lamp stability kept
• Longer ballast and lamp life owing to lower heat characteristics
• Ballasts and lamp  savings of maintenance and exchange
• Important installation costs are avoided on not having to lay double lines or in quincunxes connections
• Relatively low additional investments in installations in comparison to the great potential of reducing electricity costs
• As the reduction takes place at all the light points, there are no longer dark areas, which are dangerous for good visibility, as occurs in installations where in order to save energy, alternate points are switched off or the whole line of lights

Energy savings
The reduction of the lighting level according to the type of lamp is considered optimum between 45 and 55% that obtained in the maximum level, which corresponds to power percentage of between 50% the power absorbed from the network at the level; representing a saving of 40% the energy consumed during the whole time we have the installation in these operating conditions.

The energy saving reduction represented in the table below:

There are two basic power control systems:

• clock control systems
• manually control systems

HSI Bi-power 53x69mm

HSI Bi-power 91x104mm