It is strongly recommended that each three phase drive is installed with either a Line Reactor or a Drive Isolating Transformer connected into the main power supply. The purpose of this is to ensure a defined line impedance thereby reducing both the level of SCR induced “notching” on the supply and the total radiated electromagnetic RF noise. In most industrial systems the choice of line reactor or transformer will depend on other considerations such as the need for isolation to provide added system safety. In many instances, it will also be necessary to install a 3-phase Power Suppression Unit to reduce the effects of drive induced transients on the line.
Three Phase Drive Isolating Transformers
All the three phase drive isolating transformers are in NEMA 1, floor standing, ventilated enclosures suitable for indoor use.
- Windings: Delta Primary, Wye Secondary
- 2 5% taps, 1+ 1-
- Lug kits, weathershields, wall mounting brackets, ceiling mounts, additional taps, special primary voltages, 50Hz frequency, isolation shield.
Please contact us for dimensions and detail specifications and further options.
Three Phase Line Reactors
These are open construction for use only in a protected enclosure. Please refer to the factory for dimensions and detail specifications.
|Catalog Number||Max hp at230VAC||Max hp at460VAC||Drive MaxDC Amps||Dimensions
LF3 3-Phase Line Filter
This unit is a 3-phase Rectifier/Resistor/Capacitor network designed to reduce the drive induced switching transients on the power supply.
In general, one LF3 Line Filter can be used with multiple drives to ensure that the power quality is satisfactory if the cumulative total horsepower is less than 150 hp (ie. one 150hp drive, two 75hp drives, etc.) Please call for further information.
- Rating: 3-phase, 500 volts maximum, 50/60Hz.
- Dimensions: 7″H x 5″W x 3″D (180x125x75 mm)
Power Quality Note
To assess power quality, examine the three phases with an oscilloscope under worst case motor load conditions. Drive switching transients must never exceed an instantaneous max. voltage of 1.25 x the normal phase peak volts (1000 volts absolute maximum). If this is exceeded, a Line Filter (part no. LF3) will be required. Multiple units can be added to the 3-phase power lines to ensure that the power quality is satisfactory.
Warning! be sure to use an isolated probe with the oscilloscope
when working at high voltage!
Filters required to satisfy CE installation requirements are available. Please call for further information.