Centrifugal pump overflow trip

The flow rate is high, either the motor is too small, or there is an issue with the motor’s insulation.

If it works as soon as it’s installed, it’s likely that the motor is too small; generally, the motor is selected based on the pumping capacity required

I agree with the opinion above; in such a situation, it’s very likely that the motor is undersized. The reason for this undersizing is most probably that the current operating conditions of the pump do not match those specified in the design. You should check the original design documents to find out what the designed inlet and outlet pressures are, as well as what the pressure losses throughout the system are If the Symbol motor can be replaced, then it’s solved

There are also N ways to cause the vehicle to stop working: 1. Does the problem occur right from the start of testing, or does it start appearing after the vehicle has been in use for a few months or years? If the problem of vehicle jumping out occurs from the very beginning, it means the motor is too small; in such a case, it has to be used at a reduced capacity, for example by reducing the pump’s flow rate ； If the pump stops working after being in operation for a few months or years, it may be due to wear of the mouth ring, wear of the impeller, and other factors that lead to a decrease in the pump’s efficiency ； 2. Does it trip due to overcurrent as soon as the pump starts, or does it trip due to overcurrent after running for a few minutes or so? If the pump stops working as soon as it is started, then something is stuck somewhere, and mechanical faults need to be checked carefully ； If the machine shuts down after running for a while, then it is necessary to check the process-related factors or the motor insulation. 3. Are the inlet and outlet pressures and flow rates stable when jumping out of the vehicle? Sometimes, if the process operating conditions fluctuate significantly, such as a sudden drop in the outlet back pressure, it can lead to an increase in pump flow rate and thus motor overload. 4. Has the coupling been removed to check what the current is when the motor rotates alone? This is mainly due to the reduction in insulation of the motor’s coils caused by moisture or other factors.

If it is a multi-stage centrifugal pump, check whether the balance disk has worn out

Pumps are equipped with various interlock protections; for example, there is a low current interlock. Some companies implement such a stop mechanism to prevent the pump from running without liquid. If this situation occurs, it is necessary to check whether the interlock settings are appropriate； Another situation is that the high current in the pump itself causes it to stop ； It is necessary to confirm whether this situation occurs at the beginning of pump startup ； In the early stages of operation, there are two possible situations: one is that the current setting is not appropriate ； Or the allowed overcurrent time is too short ； If it is during operation ； It is possible that there is an issue with the pump selection or that the shutdown current setting is too low ；

Generally, it’s because the pump is too large; the valve can be reduced in size or the diameter of the impeller can be made smaller.

Overcurrent trip occurred due to the pump outlet shut-off valve being sized too large

I’m not sure if there have been any changes to your piping; a high outlet flow rate can cause overcurrent. The pump itself is likely not damaged. You might want to check the electrical aspects – it was explained clearly upstairs. The proper selection of electrical equipment is very important, such as circuit breakers, motors, relays, etc