A professional-grade pump is an investment—one that most homeowners and maintenance personnel do not want to be forced to replace. But things happen in our environment that can be detrimental to a pump, even catastrophic. Here's three reasons you may be seeing damage to your pumps.
- Low pressure. A suction line may be clogged or damaged, or the water source may have changed and can no longer sufficiently supply the pump. When a pump runs with low incoming pressure, the resulting imbalance of incoming and outgoing flow causes cavitation, which damages the impeller and other internal components. Often, there is a distinctive noise that accompanies this issue—it sounds like the pump is full of rocks. Unfortunately, by the time you identify the cavitation, the damage has often already been done.
- Unopened valves. When a zone valve doesn’t open during a run cycle, the impeller spins in captured water in the pump case. Because the water isn’t moving, the friction of the impeller heats that water to the point of causing damage to PVC pipework. As the pipework gets hot from the water, it starts to expand, becoming weaker and the walls thinner—until the point of breakage or failure.
- Improper protection from over-amperage. If the voltage coming to the pump is too high or too low, or if material gets into the impeller creating a drag, over-taxing or overheating the motor can occur. All motors 2 hp and below are required by the National Electric Code to have internal thermal shutdown protection in place. Motors larger than 2 hp do not have this requirement. In a pump system, this protection must be provided elsewhere.
These situations often occur while the pump is not being observed, which can lead to damage or even the demise of even the heartiest of pumps.
A simple pump protection solution
A Munro SmartBox is a pump start relay and pump protection in one. It includes a preset pressure sensor that alerts the control system of potential pump damage from loss of prime or run-dry. A temperature sensor can also be added to protect a pump system and pipework from excessive heat.
If a SmartBox detects an issue, it will turn the pump off to avoid damage. The next time the irrigation system is set to come on, the SmartBox will turn the pump on. If the issue was resolved, the pump will run as usual. If low pressure or high temperature (if it includes the optional temp sensor) is detected, it will turn the pump off again.
Offered in the same powder coated steel or stainless steel enclosure as the pump start relay, the Munro SmartBox is a smarter way to run your pump.
 Munro StartBox |
 Munro SmartBox |
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| Works with most residential turf irrigation pumps (24v, 110v, 220v coils) | ✔ | ✔ |
| Color-coded wiring for easy hook up | ✔ | ✔ |
| Safe and reliable UL and CUL listed relay and enclosure | ✔ | ✔ |
| Pressure sensor that alerts the control system of potential pump damage due to loss of prime or run-dry | N/A | ✔ |
| All external devices are powered at reduced 24 volts. Low risk of line voltage harming people or pets. | (Optional) | ✔ |
| Thermal protection from damage due to over amping | (Optional) | (Optional) |
| Adjustable time delay (factory set at 30 seconds) | ✔ | |
| Low amperage input (2-wire system compatible) | ✔ | ✔ |
| Three phase | ✔ | ✔ |
