Sporadic pump Trip 2

[EEENGRX]

I have a pump that is sporadically starting and stopping when the level in the sump gets low. What do you think might be a good solution to this issue

 

[georgeverghese]

Does this pump normally start and stop based on level in this sump ( level control high - start; level control low - stop)?

 

[EEENGRX]

It uses a Float switch.. The waves in the sump make it stop and start. I am thinking of putting a pneumatic time delay relay. Let me know what you think and any other ideas you think could work better

 

[thebard3]

Most float switches have hysteresis, or separate on/off levels to keep that from happening.

 

[georgeverghese]

Okay, this timer delay may be one way. Presume you have some reason why you alternatively cannot raise the auto start level high position.

 

[EEENGRX]

What other ways can you think of?

 

[LittleInch]

You need to describe or find out how your stop start system works.

This is either the float switch not working or not set properly or a poor control system.

Either way find out what you have, how it is supposed to work and then fix it.

 

[danw2]

A sump has a wide deadband level switch that turns the pump on at the high point, latches the contact to keep the pump running until the level hits the low point where the control contact changes state, the pump stops and the control contact latches in the OFF position until the level switch reaches the high level point.

If the switch contact is not latching open once the pump gets to the low state, then there's something wrong with the low position sensing function or the latching function.

 

[georgeverghese]

If this float switch has a limited operating range, then you may need to either find another model of float switch with a much wider operating band, or else switch out to a dp cell type level transmitter. If this sump is open to the atmosphere, then a dp cell in level service is equivalent to a low range pressure transmitter. For a PT or LT, to avoid weeds, suspended solids and/or bugs from getting into the impulse line, ask for a diaphragm sealed impulse line.

 

[njp8332]

I have a pump that is sporadically starting and stopping when the level in the sump gets low. What do you think might be a good solution to this issue

i have see something like this in mercury type float switches where mercury makes contact if float is tilts as liquid level changes. If there are waves in sump, this might disturb mercury and trigger pump.
What kind of float level switch is it ? mechanical or liquid based ?