Active Harmonic Filters (Power Quality Filters or PQF)

Rolla often supply sections designed to contain Active Harmonic Filters either stand alone or as part of a larger Motor Control Centre suite.

Over the years the increase in the use of DC power supplies, variable speed drives, UPS systems and soft start units has meant more and more end users needing to fit such units. They provide a high degree of sensitivity and a comprehensive way of ensuring compliance with power network quality requirements (G5/4).

Single unit, capable of providing up to 300A of active filtering.

Air inlet filters on the right hand side, fans on the left. Air is baffled internally to prevent recirculation. Doors are interlocked with the master on the right.

Internal view showing stacked filter modules. Each module provides 60A of filtering and up to 5 modules can be fitted in each cubicle. They are mounted on shelves ensuring easy access for maintenance, replacement or upgrades. All the mounting facilities are provided by Rolla leaving our customer to complete the wiring. Proper segregation between airflows is essential to ensure adequate cooling but the vertical baffle is also hinged to allow full access when required without disturbing the wiring more than is necessary.

Fuseswitch isolator at the top (400A) is door interlocked with power distribution provided specific to each project. The isolator will either be connected directly to the busbars or supply cable if stand alone unit. (Note all wiring is provided by our customers - we provide the steelwork and busbars).

Typical individual Power Balance 60A filter module courtesy of PQ Management.

Standard 7" display - we punch the door ready to accept a unit like this.

Filter sensorbox fitted below the filter modules - Rolla provide the mounting facility directly below the filter modules so that the cabling is made easy.

More details of harmonics and how to manage them can be found here.

Typical layout in drawing form showing overall sizes.