Nelson Service & Support
Nelson 700 Series (All Models 700 & 760) Horse & Livestock Waterers
Testing Thermostat – Nelson 700 Series Automatic Waterers
Installation must be made and maintained in strict accordance with national local electrical codes. Installation must be done by a qualified electrician. Improper electrical installation or maintenance may result in serious injury or death for personnel or animals or damage to structures.
Testing the thermostat usually requires removing the thermostat from the waterer and testing it for continuity with an OM or multimeter. A multimeter can be purchased at a local home improvement center.
First shut off the electric power to the waterer and shut off the water supply at the brass shut off valve. Remove the pivot beam and cage for easy access to the junction box. This is accomplished by removing the lead weight, then removing the cotter key from the tapered end to the brass pivot shaft to slide the shaft out. The pivot beam and cage may then be removed as a unit.
Next disconnect the thermostat wires within the junction box. The thermostat should be connected between the hot wire of the power supply and the black wire of the heater. Then remove the mounting nut located inside the junction box from the thermostat housing. The thermostat is free to be removed. Place the thermostat in a freezer for half an hour to close the switch. Then test for continuity using an OM meter. If continuity is noted the thermostat is working properly. If there is no continuity replace the thermostat.