Application: Rubber Mixer

Replacement Drive: Parker SSD 591P – Frame Size 6

The existing BRUSH Falcon DC drive was over 30 years old with no available spares. The control and power was spread across 3 adjacent control panels. The first section held the main power stack and electronics, the middle section isolator’s bus-bars and contactors, and the last section the switchgear and field controller.

The bus section ran across the rear panels with current transformers for DC drive feedback mounted alongside the C-R networks for suppression. The Brush DC drive via galvanic isolators sent 4 main signals to the mixer computer system:

• Armature Volts
• Armature Amperes
• K Watts
• Speed.

The BRUSH DC drive consisted of a 4 quadrant, 12 pulse DC drive with a high overload of 4020 Amps, this fed the ABB 1MW DC motor. The oil cooled 1445KVA phase shift transformer provides a 635 VAC supply to both main DC drive stacks. The BRUSH DC drive panel is very well made and is constructed in a bespoke manner for the niche DC drive components; in the stack section it had no back plate.

The panel was modified and reconstructed using welded and bespoke CNC components to house the new DC drive. The compact nature of the Parker SSD (Shackleton System Drives) makes it very suitable for the panel; frame Size 6 of the 591P range.

The field controller of the master DC drive was taken away from a separate field controller located in the end panel integrated into the main DC drive, making it convenient to remove the external field failure system and control interlock; these interlocks are now done in the 591P. The new 591 DC drive feeds the motors 14.4Amp, 310VDC field from a custom wound step down transformer.

The Rubber mixer DC drive retro fit was carried out over a short shutdown period of 5 days and the commissioning completed and tested on Sunday afternoon, thus making it ready for a Monday morning start up.

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