Last week, we reviewed “drought insurance” for submersible water systems using the Pumptec family of products. This week, we will look specifically at Pumptec and how it protects a system from damage in many other ways.
Pumptec is a microcomputer-based pump protection device that monitors load and supply voltage in single-phase systems. It protects against five conditions that can be dangerous to a motor: underload, overload, high voltage, low voltage, and rapid cycling.
Underload, also known as dry well, includes any condition that leads to the motor becoming “unloaded”. Besides a dry well, this could be an air- or gas-locked pump, failed impellers, a line blockage, or a check valve that is stuck closed. Any of these will cause the motor to unload. Once the unloading reaches a predetermined threshold, Pumptec will remove power from the motor. Anytime an underload condition occurs, the load light will come on steady and stay on until the reset time is achieved. This reset time can be set from two minutes to four hours, or a manual reset can also be specified.
Overload is the very opposite of underload and can occur when the pump becomes clogged with sand or other debris. If this happens, Pumptec will cut power to the motor and the LOAD light will flash. Unlike an underload, there’s no reset time for an overload condition. Pumptec assumes that it warrants investigation and probably won’t restart. The unit must be manually reset by cycling power to the unit.
In both of these situations the system goes from pumping a normal amount of water to pumping very little or no water. To monitor these conditions, Pumptec uses a threshold point on the power factor curve. As we know from our previous AID, power factor is the relationship between voltage and current. Each motor rating has a unique power factor curve, and thus a unique trip point.
If a motor experiences a loss of water for any reason, the power factor of the motor begins to drop rapidly. When it gets too low (i.e. reaches the threshold), Pumptec shuts off the motor and allows the well to recover. After a predetermined timeout, the system will come back on; however, if the load does not reach or exceed the needed power factor, the system will shut off again. If power factor gets too high, Pumptec will also shut off the motor, but in this case, a manual restart is required. You can see how these power factor scenarios correlate to underload and overload conditions.
As we mentioned earlier, Pumptec not only protects against underload and overload but several other damaging conditions.
High or low voltage can create a multitude of problems for a motor electrically. That’s where Pumptec comes in: to monitor the installation’s supply voltage. If voltage drops below or exceeds 10% of the rated voltage (either 115 or 230 volts), Pumptec will automatically shut down the system. If the voltage is low, the voltage light will come on and remain steady; if the voltage is high the light will flash.
Rapid cycling is the final condition monitored by Pumptec. Characterized by too many starts in a given period of time, it is most often caused by a failed pressure tank or switch. Because rapid cycling can cause serious damage to an entire system, when it is detected, Pumptec will remove power from the motor until it is manually reset.
It is important to note that because Pumptec monitors power factor, which is a unique measurement for each motor design and rating, this protective device cannot work on just any motor. Pumptec is uniquely engineered and designed to work only with Franklin Electric submersible motors from 1/3 through 1.5 horsepower.
For more information about Pumptec please visit our website and be sure to stay tuned for next week when we will continue to explore the Pumptec family of products.