12-Pulse & 18-Pulse Low Harmonic Solutions
Compact, cost-effective and completely integrated system for applications requiring enhanced harmonic control. Packages seamlessly combine the reliability and advanced performance for the VLT® Series Drives with best in class 12 & 18 pulse harmonic reduction technology. The result is a complete solution for the supplier you trust.
- 460-480VAC +/-10%
- 15 to 250 HP
- -10º to +40º C (14º - 104º F) ambient
Enclosure options - floor mounted panels
- NEMA UL Type 1
- NEMA UL Type 12
- NEMA UL Type 3R
Each unit will ship completely assembled in a free standing enclosure labeled as conforming to UL Type 1, 12, or 3R as required by the installation. Units require simple four-wire-in and four-wire-out power connections. The entire package is UL 508A Industrial Control Panel.
All 12-Pulse bridges are separated from the VFD's rectifiers. These bridges are separate from the VFD's standard 6-pulse bridge to ensure appropriate load sharing and harmonic reduction. Input to the rectifiers is an electro-statically shielded phase shifting drive isolation transformer.
All 18-Pulse units include three 6 diode bridge rectifiers. These bridges are separate from the VFDs standard 6-pulse bridge to ensure appropriate load sharing and harmonic reduction. Input to the rectifiers is an auto-transformer with the design criteria listed below.
- Main fused disconnect
- Main fused disconnect, VFD fusing, 3-contactor bypass, advanced relay logic including: common start/stop in VFD and bypass mode, automatic bypass on failure, run permissive circuit in VFD and bypass modes, and under voltage protection in bypass
- Add reduced voltage solid state soft starter to any bypass configuration
18-pulse design criteria
- Automatic shutdown with phase loss
- Integral high impedance line reactor mated with the transformer by the transformer manufacture to ensure optimum performance
- Newest topology that will perform as designed on a phase unbalance up to 2%. Older design topologies have less performance on voltage unbalance, usually specified as 1/2% unbalance
- Thermal switch on each transformer coil
Low harmonics solution benefits
Meet IEEE 519-1992 at drive input terminals (18-pulse)
Help meet IEEE 519-1992 at the system level
Improved total power factor
No external filters or transformers needed
Improves overall electrical system efficiency