Protection against earthing faults and short circuiting. External controls available for manual pump-out and washing. The Varivac system consists basically of a Danfoss VLT5000 Frequency Converter which controls the vacuum pump electric motor speed in response to signals from a vacuum transmitter. The Danfoss VLT5000 is a logical choice as it has been factory-designed for PID control and has low electrical interference and emission. This is critical in dairy sheds where stray voltages of 1.5 Volt can seriously affect animal health and milking performance.
Cows are nearly fifteen times more sensitive to electricity than humans.
The Nuphlo pump, manufactured in New Zealand, is of the positive displacement flexible rubber impeller type, capable of self-priming and pumping out against a vacuum or suctioning against a negative head of up to five metres. The pump is made of grade 316 stainless steel, polished to food hygiene standards. Simply by undoing the two wingnuts, it can be stripped quickly for cleaning or maintaining the seal. The flexible rubber impeller is made from Viton rubber which can withstand temperatures to 90 deg C and is suitable for CIP cleaning. A standard mechanical seal is fitted with the option of a double flushed seal for crystallising or viscous products.