The customer had experienced failures (due to debris becoming lodged in the vane bearing) with the paddle wheel flow meters previously being used.
They were also looking to reduce the component cost.
Grundfos Direct Sensor™ were contacted to provide a solution if possible with the non- moving parts Vortex Flow Sensor (VFS).
The Grundfos Solution
The VFS sensor had to have a new interface board developed to handle the power supply & signals out of the VFS 1-20.
This was done in collaboration with their electronics design partner and the product went into production in Early 2009.
One question still to be resolved is the earthing situation where customers use plastic composite piping. We are investigating an earth lug to be attached around the brass fitting on the VFS 1-20 for Whale and for other ranges up to VFS 20-400. From customer feedback this situation arises in approximately 1 in 20 installations. The earthing solution will be supplied with every kit to reduce calls to the customer helpline.
See the attached case study by Whale Pumps for installation etc.
The no moving parts technology used in the VFS provides for a longer service interval for the Dry Deck 20 installation. For Whale shower drainage kits this further increases reliability. A side effect has been that the installer no longer needs to install a filter to protect the flow sensor.
The earthing issue when it occurs is resolved by advising the customer to add a supplementary earth from the brass connector on the Grundfos to an earth tag on the electronics board. With the increased use of plastic water piping this is the only location on the pipe work to get an effective earth point. The availability of the earth lug designed for the Grundfos sensor will simplify the earth connection. This will make installation simpler.
The Grundfos sensor has been a benefit to the Whale range of shower drainage kits. The Grundfos sensor 1-20 ltrs/min covers the majority of showers both electric and power showers on the market today.
Working with the Grundfos sales engineer has made the transition from vane type flow sensor to the VFS type relatively straight forward. Confidence was built in the use of VFS in our application, through our in house laboratory tests and field trials. Grundfos has provided a quick response in resolving specific installation issues and technical queries. We now rate Grundfos as a valued supplier, ready to help when asked.