Troubleshooting Tips
Pump Will Not Start
Discussion
Obviously there are many possible reasons why a pump will not start. The following list starts with the simplest, most obvious, and easiest to diagnose problems, and then progresses to less likely and more difficult problems to diagnose.
Most Likely Suspects
1. STATION DISCONNECT – Is the main circuit breaker disconnect on station control panel off or tripped?
2. OFF STATION DISCONNECT – Is the disconnect at another location feeding power to station off, tripped, or a fuse blown?
3. POWER TO THE SITE - Power provider problems such as bill not paid, main fuses blown, entire power grid failure, etc.
4. RAIN SWITCH – Is the rain switch active? Is the rain switch failed and therefore not allowing system to operate.
5. NO CLOCK DEMAND SIGNAL – CLOCK DEMAND SYSTEMS ONLY - On clock demand systems, the irrigation controller may not be signaling for a start, or the wiring is incorrect or failed, or the relay has failed.
6. CONTROL FUSES / CIRCUIT BREAKERS – Internal control panel fuses or circuit breakers may be open.
7. FLOW ALARMS – The station may be off because of a declared flow alarm (NO FLOW, VOLUTE, LOSS OF PRIME, LOW PRESSURE, etc.) On older systems the alarm indicator lights were incandescent bulbs. When these bulbs burned out the fault is not indicated by a light. On newer equipment the lights are LED bulbs that are extremely dependable and unlikely to ever fail. Also, it can be difficult to see a light in direct sunlight, look carefully and shield the lights from the sun to be sure they are or are not on. Irrigation Craft stations have a lamp test feature. Depress the RESET button for 12 seconds and all lights except the RUN light will turn on allowing you to determine if any bulbs have failed.
8. LOW LEVEL - If the station is equipped with a low water level system, the pump may be off because of a low water level or malfunctioning or mal-adjusted low level system. Are the level floats working properly? Are the float wires connected to the station properly?
9. OVERLOAD TRIPPED - On newer stations this is indicated by an alarm light, and can be reset by pressing the RESET button. On older stations the control panel door must be opened, and the overload reset button pressed.
10. STATION ISOLATION VALVE – Is the station discharge valve is closed?
11. MAINLINE ISOLATION VALVES – Are there any hidden or underground mainline isolation valves that may be closed?
12. PRESSURE SWITCHES - Pressure switches may be mal-adjusted, malfunctioning, or pressure tubing to the switches may be kinked or clogged.
13. START RELAY – Is the pump start relay turning on and off when commanded to by the irrigation controller or PLC? If the relay is turning on and off properly on command, are the relay contacts working properly by signaling the station to start? Please note that Irrigation Craft uses a pump start relay on our PLC stations to protect the PLC internal contacts from wear damage possibly requiring that the PLC be replaced. On other brands of stations they may not have a start relay outside the PLC, then the PLC would have to be replaced if the internal relay fails.
14. START RELAY PRESSURE DEMAND - If the PLC signals the start relay to operate, is the relay operating? If the relay is turning on and off properly, are the relay contacts working properly by signaling the pump to start?
15. PLC POWER - With the power turned on, a small light should be on indicating that there is power to the PLC. Check and make sure that there is 24 VDC to the PLC with a volt meter set to the DC setting. If there is no power to the PLC, then the power supply may have failed, a fuse or circuit breaker is open, or the control transformer has failed.
16. PLC FAILURE - Examine the PLC closely with the power on. Is the PLC indicating properly? Are there LED lights indicating the PLC is in the RUN mode? Are there any LED lights indicating that inputs and outputs are active? If there are no lights on and yet there is definitely 24 volts DC power feeding into the PLC, then the PLC has failed.
17. TRANSFORMER FAILURE – Transformer failures are extremely rare. If there is high voltage entering the transformer and no low voltage is coming out of the transformer, then the transformer has failed.
