YORK YK — Harmonic filter - High total demand distortion

The panel shows Harmonic filter - High total demand distortion. The manual lists this exact text, in this capitalisation, as the only display form of the message. It appears on the OptiView Touchscreen Control Center of TM, VSD, and LVSD model drives and is grouped with the variable speed compressor drive safety fault messages.

This is an OptiView shutdown. It signals that the harmonic filter is not working as it should and that the input current to the VSD/filter is no longer sinusoidal. The trip condition is a total demand distortion (TDD) that stays above 25% without interruption for 45 s. In the filter option supplied by YORK, the value shown as TDD is the total RMS value of all harmonic current the main power supplies to the VSD, divided by the chiller FLA and given in percent. For comparison, the manual notes that a standard VSD without the optional filter typically shows an input current TDD on the order of 28% to 30%.

• The harmonic filter is not working as it should.
• The current entering the VSD/filter is not sinusoidal — the TDD has held above 25% for 45 s without interruption.

• Shutdown threshold: TDD above 25%, held continuously for 45 s.
• Definition of the displayed TDD with the YORK filter option: total RMS value of all harmonic current carried from the main power into the VSD, divided by the chiller FLA and expressed in percent.
• Reference value: a standard VSD without the optional filter typically has an input current TDD of about 28% to 30%.

Clearing is done at the control center. The chiller can be started after the Clear button is pressed next to the listed event on the Systems Details screen.