• Article 7 - June, 1991

 

Harold Spagatinie and Close E-Nuf Plumbingtroubleshootingsolution and conversions for using a HeliotropeQuadra-Temp (TM)with 30 K Ohm sensors^©

 

In the last newsletter, Harold Spagitini was having problems with his SDHW system. One of the pumps would not turn off. The controller and sensors were checked and found to be working properly. As it turns out, a field winding in the pump was shorted to the pump housing. That allowed the current to return to the controller via the green ground wire. However, that was not the total problem. Close-E-Nuf construction, Harold's contractor, had wired the power cord from the controller to the wall receptacle backwards, i.e., the hot and neutral wires were reversed. Because of this, the hot wire was fed directly through the controller and was not switched by the relay. When the controller relay was energized, power was delivered to the pump and the current returned via the neutral wire and ground wire. When the controller relay was de-energized, power was delivered to the pump and the current returned via only the ground wire. The electrical path was complete regardless of the relay status. Re-wiring the controller power cord and replacing the pump solved the problem. Those solar sleuths correctly identifying this problem were Bill Klessinger and Mike Hellem. Good job, guys.

 

This month's tech note involves measuring the temperature of a 30 K ohm sensor with a Heliotrope Quadra-Temp (TM) Monitor. The Quadra-Temp (TM) can be used with either 3 K ohm or 10 K ohm sensors, but not 30 K ohm sensors. If a 30 K ohm sensor is connected to the Quadra-Temp (TM), the read out will not be the true temperature of the sensor. Below is a conversion chart that will allow you to correlate the monitor's read out to the temperature of a 30 K ohm sensor.

 

 

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