1. Maintaining & Troubleshooting pump problems in the field
NC-AWWA Spring Symposium
2018
Asheville, NC
Maintaining & Troubleshooting pump problems in the field
Tim Hebert A&W Electric, Inc. (704)

2. What will we discuss today?
Basic Principles of electric Motor and Pump Operations
Identify Key component parts
Field Diagnosis of system and operational issues
Order, type, and methodology of field testing
Checklists for use in Maintenance and troubleshooting
Tim Hebert A&W Electric, Inc. (704)

3. What do pumps do ? How?
Boost pressure of pumpage to either lift or transfer pumpage.
But How does it do that?
Squeezes pumpage through a smaller discharge than suction
Impellor spinning on motor shaft collects and “slings” pumpage
Size, Shape, and speed of impellor impact volume (flow) and head (rise)
Shape of the volute forces pumpage through impellor to discharge.
Impellor mates with wear ring to drive the efficiency of the pump.
Tim Hebert A&W Electric, Inc. (704)

4. Pump Station Inspection & Maintenance
Testing
Maintenance
Next Steps
We need to think about
Frequency – Based on age & condition of station as well as influent
Scope – How often do we want to do each test?
Maintenance – How can we prevent problems, extend life?
What happens when we run into an issue – Seal Fail, overamping, etc.
Tim Hebert A&W Electric, Inc. (704)

5. Inspection Process - Electrical
Is voltage to the control panel within 3% of nominal
Is voltage balanced across all three phases
What is the amp draw of each of the motors? Trend of amp draw?
What is the condition of wire and starters inside the panel?
Contactor coils burnt and dark
Loose connections?
Is SO cord rotted and cracking? Swollen?
Tim Hebert A&W Electric, Inc. (704)

6. Inspection - Operation
Do pumps cycle adequately?
Are all alarms and control lights working?
Is an alarm condition communicating back to Scada/Mission?
Are contactors pulling in when control asks them to?
If alternating relay, are pumps cycling properly?
Tim Hebert A&W Electric, Inc. (704)

7. Inspection mechanical
Are floats clean? Are they operating?
How do we test floats?
Is well excessively dirty:
Trash and debris in well
Sand and grit?
Flow test – are we flowing to the curve? What is the trend?
GPM
PSI
Drawdown
Have we inspected volute for blockage?
Tim Hebert A&W Electric, Inc. (704)

8. Causes of Problems – Electrical and Mechanical
Poor voltage delivery
Bad/Loose connections
Loss of phase
Weak/ Dirty contactors
Bad cable in pump
Bad windings in electric motor
Blockage in Well
Blockage in pump
Cavitation
Worn impellor
Bad mechanics in pump causing extra load
Tim Hebert A&W Electric, Inc. (704)