PREFACE: The longevity of a Nemo Pump is mainly dependent on the type of use it is put to. Properly installed and used in applications for which it was designed, a Nemo Pump can provide years of trouble free service. Improperly installed and/or used, it’s service life can be reduced to a matter of weeks or months. The intention of this Use Guide is to help determine how, why, and if a Nemo pump is a practical choice for your application. There are four main causes of failure of a Nemo pump unit, any of which can result in the flooding of the Nemo Case. The pump would thence become inoperative, usually beyond cost effective repair:
1. FAULTY INSTALLATION: One example of faulty installation would be improper sealing of the wire lead splices to the dropwire. This could allow water to enter the wire, migrate down the stranded wire of the leads, and flood the case. This result as well as other installation faults can be avoided by diligently following the simple installation instructions provided with each pump.
2. OVERHEATING of FLOJET MOTOR: The Flojet motors used in Nemo Pumps are designed for intermittent duty service, which means they will overheat if overloaded or during extended run times under heavy load. A safe overload run time however is not an exact period that is applicable to all site situations; very cold water from a drilled well will extend the run time, whereas warmer water from a cistern/reservoir/stream type source will shorten the run time. The Nemo in our well in PEI Canada, for example, has been delivering water to house and guest cottages for the past 18 + years, but it is running submerged in the cold water of a drilled well and hardly ever runs for more than an hour or two at a time without having a cooling break of 15 minutes or more between run times. This type of solar charged battery installation (with a holding tank and a pressure tank) is a most appropriate and cost effective use of a Nemo Pump, and the run times are simply and automatically controlled by not exceeding normal household use limits. Similar or other means of controlling run times should be provided in direct solar applications or in applications where the intake water is relatively warmer than well water. This can be as simple as the manual monitoring of an on/off switch, but an automatic timer switch and/or a float switch in an appropriately sized holding tank would also attain the desired effect and would provide the convenience of fully automatic operation. Another cause of overheating would be overloading caused by excessive pressure. Since the Flojet pumps are not equipped with internal bypass valves, overloading can occur if the total system pressure exceeds the rated capacity of the pump (100 PSI/230 FT), or if the discharge pipe to the pump becomes frozen or otherwise closed between the pump and the pressure, float, or other electrical shutoff switch.
3. FLOJET DIAPHRAGM FAILURE: If a diaphragm fails it will flood the case and the pump will stop running. However, the life of Flojet motor brushes is (very conservatively) rated at 2000 hours and a Flojet diaphragm will almost always last at least as long as the wear-down life of the motor brushes. An exception is where there is a substantial buildup of pressure inside the Nemo Case caused by excessive overheating and overloading of the Flojet motor. Such pressure can compromise the diaphragm and thus flood the case.
4. FAULTY NEMO CASE SEALS: The Nemo case seals (the main case seal between the inside of the case and the rim of the Flojet pump head, the seal plug at the wire leads, and the seal at the Flojet head screws) have all been designed and extensively tested to be extremely watertight. These seals are fully fortified with the highest grade underwater marine adhesive sealant obtainable. Under normal operating conditions and within considerably extended margins beyond such conditions the Nemo case seals will very rarely fail. The exception is where there is a major buildup of pressure inside the Nemo Case caused by extreme overheating of the Flojet motor. Such pressure may compromise a seal and thus flood the case.
CONCLUSION: The information above directly relates to your decisions regarding the suitability, purchase and use of a Nemo Pump for your specific application. Since we have no control over how you install and use a Nemo Pump, and also no control over the manufacture of Flojet units, this information also directly relates to the Nemo Warranty. The warranty does not cover failures caused by faulty installation and use of a Nemo or faulty Flojet motor/head units. The warranty does cover failures caused by defects in the materials and/or workmanship of the entire Nemo Case. Since any failure caused by a defective case would occur within hours or days after the installation and use of a Nemo Pump, the Nemo warranty is therefor limited to the 60 day period following the purchase date.