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) 363-3144 tim@aandwelectric.com

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) 363-3144 tim@aandwelectric.com

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) 363-3144 tim@aandwelectric.com

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) 363-3144 tim@aandwelectric.com

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) 363-3144 tim@aandwelectric.com

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) 363-3144 tim@aandwelectric.com

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) 363-3144 tim@aandwelectric.com

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) 363-3144 tim@aandwelectric.com