Cat Pumps come on at 500psi

[dieselzack]

Hi all - I just noticed all the cat pumps (4 of them) come on at 500psi rev up for a second then cut out and keep doing that as soon as the pressure hits around 500psi. Now I should say it only does it when the bays are calling for pump action (rinse, etc), the gun trigger is off and the bay is active with a customer. When the bay is inactive it doesn't do it. The VFD's are ok I had an electrician check them out and one of the pumps has had the output flow control, electric pressure switch, etc all replaced.

Any ideas?
Thanks!

 

[borumrm]

Interesting that it is all the bays....that would seem to indicate the problem has a common source. How is the water supply to your pumps plumbed? Do they each have a dedicated hose coming from the supply tank? They should so it almost sounds like the pumps are starved for water.... is there an obstruction from the main supply tank...on my tank there is a screen at the bottom to filter out any trash...I wonder if yours is clogged?

 

[MEP001]

What brand of equipment do you have?