Hybrid Pond Pumps
Seldom has a product emerged in any industry that is known by so many different names. The pumps in question are also known by the names Asynchronous, Magnetic Wet Rotor, Asynchronous Hybrid Magnetic Drive, Hybrid Pumps, Energy Saving Pumps, High Efficiency Pumps, and The New Mag Drive Pumps. All of these labels are in some way correct but have caused a great deal of confusion among new installers, retailers and consumers. These pumps are truly asynchronous, meaning that the impeller spins only in one direction like in a direct drive. This is different than the true magnetic drive pump which changes direction (synchronous) each time the pump is restarted.
The Magnetic Hybrid pump can be identified by the following characteristics:
- A large curved vane impeller mounted on a rotor; 2. Impeller assembly rotor is not a magnet; 3. Total head is somewhat lower than comparable flow direct drive pumps; 4. Low energy consumption; 5. Typically available at a lower price than comparable flow direct drive pumps but higher than Magnetic drive pumps.
Unlike the rare earth magnetic drive pumps, which use an actual magnet, the hybrid only creates a magnetic field when the power is turned on. The impeller assembly is exposed to the water just like in the magnetic drive pump but in these pumps the rotor consists of a large steel or composite alloy (usually stainless steel) to which a curved vane impeller is attached for high pump output. By varying the size of the rotor and impeller the manufacturer can increase the GPH flow of the pump. The technology for these pumps has increased rapidly since their introduction to the pond industry a few short years ago. Flow rates have increased dramatically and you can now find these Hybrid Asynchronous pumps with flows between 800 GPH to an amazing 10,000 GPH.
The hybrid types of magnetic induction pumps are perfect for low and medium total dynamic heads. The impeller is similar to those on direct drive pumps as it will spin in only one direction increasing power and flow. According to Jon Lottes, President of Anjon Manufacturing, slightly larger pump housings have allowed for increased rotor and impeller sizes, which have increased the maximum flows up to 10,000 GPH and maximum heads to over 30 foot. Additionally Jon adds that larger rotor sizes mean a more efficient pump due to less slippage around the rotor.
The asynchronous Magnetic drive pumps are also very economical to operate with pumps in the 1,000 to 5,000 GPH running on between 100-400 watts. The larger pumps in the 6,000 to 10,000 GPH range will operate on average between 500 and 1000 watts.
In order to increase volume of flow and head pressure the manufacturers of these pumps have had to greatly reduce the space between the rotor and the rotor housing. The reduction of the space around the rotor means less slippage and more power but the extremely tight fit allows for very little water circulation or cooling of the rotor. Calcium deposits are attracted to the heated steel rotor and deposits can cause further circulation loss. While these hybrid pumps are generally very long lasting the primary cause of failure is seized rotors. Rotors are made of corrosion resistant stainless steel but Demi Fortuna of Atlantic Water Gardens adds that the Chromium molecules that retard the corrosion are often worn off the surface by heat and friction from small debris becoming trapped or calcium buildup. It is strongly recommended that the hybrid pumps be installed in a screened water environment to protect the pump from debris such as sand or grass clippings.
Head heights have increased steadily for the hybrid pumps but to date they still lag behind direct drive pumps. At this time their use is limited