Dry Pump Issue

Using Arduino Motors, Mechanics, Power and CNC
#1

Hi community,

I am using a 12v dc pump for a water distribution system, the pump runs dry sometimes which causes in damage of the pump, I have a trigger to turn off the pump after 5 seconds if the current is below
600 Milliamp, now there is something that the motor current wouldn't drop from 1000 or above in 5 seconds and the pump is running continuously dry. The pump current, while it's running dry sometime the current is above 1000 milliamp, this confuses me.

How can I avoid the pump from getting damaged while running dry?

Cheers,

#2

I should think a better way to prevent damage to the pump is to monitor the water level with a float switch.

Or change to the type of pump that can run dry without damage.

…R

#3

The pump current, while it's running dry sometime the current is above 1000 milliamp, this confuses me.

It is very likely that the pump has been seriously damaged by running it dry, so the motor current cannot be used to detect a problem.

#4

Awais-1:
Hi community,

I am using a 12v dc pump for a water distribution system, the pump runs dry sometimes which causes in damage of the pump, I have a trigger to turn off the pump after 5 seconds if the current is below
600 Milliamp, now there is something that the motor current wouldn't drop from 1000 or above in 5 seconds and the pump is running continuously dry. The pump current, while it's running dry sometime the current is above 1000 milliamp, this confuses me.

How can I avoid the pump from getting damaged while running dry?

Cheers,

IF your pump is completely submersed in water, then it is using water for bearing lubrication.

Paul

#5

I have used a vacuum switch on the pump suction inlet to switch off after a certain delay after suction loss, but don't know anything about your pump and situation. Post some details.

#6

Water level switch in the pipework seems a good bet to me - a float switch may be over sensitive to
flow or contaminants, I suspect there's a capacitive sensor that would be more robust available.

Differential pressure sensor across the pump might also be effective.

#7