Borehole problems in building site
New post dedicated to explain, how Head Pumps use solve borehole problems in building site.
I already told you that we use to install borehole pumps in building site, to get low the groundwater level and allow the excavations like you can see in this previous post: https://headpumps.com/en/head-pumps-en-obras-civiles/ and that we are able to solve very important problems, like in this other previous post: https://headpumps.com/en/fixing-borehole-pumps-in-contruction-site-2/
Today we are going to analyze another case of “mysterious” borehole pump failure in building site.
Pump control box in thermal protection
They called me from the building site because two borehole pumps are not working.
I go to the place and I see two pump control box in Thermal protection. This is the situation:
https://youtube.com/shorts/raNAMck_JE4?si=CvEnwLdN_y1nYgw0
The red thermal protection is on. Why?
The customer ALWAYS starts blaming the bad quality of the pump or the installation: “The old pump lasted 20 years” but in the submersible pumps world, customer is almost NEVER right and often lies, so a pumps professional has to focus on the facts and not on the customer words.
First thing to do is restart the pump, check the Intensity value and check if the thermal protector is correctly set.
Facts
Fact 1: when I restart the pump I notice a very high intensity value and I see the thermal protector set correctly. The customer claims warranty and two new pumps quickly reinstalled.
A normal plumber at this point elevates the two pumps and replace them with two new ones. A pumps professional keep on analyzing the situation.
Next step, electricity test. Since we are talking about three phase electricity, I measure the tension between the three wires.
Fact 2: the electricity value is not correct. There is a lot of difference of tension between the three phases.
This kind of problem can be caused by a broken cable, so I go to measure the tension at the electricity box where the electricity cable come from.
Bad news: in the electricity control box I see the same difference between the three phases…so I call the supervisor and I tell him the facts .”IMPOSSIBLE” he goes – The electrician came yesterday and left everything perfect – he states, so let’s talk with the electrician.
After to tell the whole story to the electrician – It has got nothing to do with it… – he says, and somehow he is right since the control boxes they use in building site are quite simple, don’t have any kind of protection against low tension or phase mismatch. I explain to him that the pumps have probably ran with that electrical problem for a very long time, then probably the motor got overheated and eventually the termal protector tripped.
Phase mismatch
The explanation is not enough for the electrician to come to the building site. He asks me to make a video to check with his eyes the phase mismatch this is the video: https://youtube.com/shorts/Xt6DE7HaP9g?si=YGBC4wdIjAiZcgHE
The electrician checks the video and tells – You have to make the same measurements at the main electricity box – so me and the supervisor go to the main electricity box and repeat the test. Same result and the answer of the electrician was – It’s not too much difference between the phases. If the crane works, it have to work the pumps too -.
I remember to the electrician that he also has to measure the tension between each phase and the neutral… so me and the supervisor repeat the test between the test between each phase and the neutral and yes, the electrician eventually decided to come to the building site to replace a bloody fuse somewhere.
Waiting for the electrician, I could test the motors of the two pumps. We don’t know how much time the pump ran with that phase mismatch. The situation probably got worse little by little before the thermal protector tripped, so the motor could be totally damaged.
A professional knows that if the motor is damaged or in bad conditions he will have to come back to fix it soon, so before to run the pumps again I made tests.
Electrical tests
With the tension off, I made three electrical tests on the pump motor: continuity test, resistance test and insulation test. The two motors pass all the tests so when the tension came to be 400V on each phase, I could reconnect, run the pumps and go away.
Remarks
This post is specially dedicated to that supervisors that don’t trust and to those engineers sat in a comfortable office far away that blame me to waste time (specially in case like this, where their workers would have replaced the pumps in a hour and would have them burned in a week eheheh) and to those building site workers that believe they are good because they install 10 pumps in a day.
A pumps professional works in a different way. A profesional allows you to save time, money and to avoid problems. without a professional you are died.
Trust in a real pumps professional. Trust in Head Pumps.
