Leachate pumping systems should be checked frequently and inspected minimally, once a year and, ideally, every six months. Familiarity with the operation of the station and comparison of carefully kept records will greatly ease the troubleshooting of such systems and will often catch problems before expensive catastrophic failures.
Check the general integrity of the system controller enclosure, insuring that its weatherproof gasketing, hinges and locking mechanism are in good condition, the enclosure is dry and that all cable, alarm and sensor entries are sealed against intrusive moisture and gasses from both outside and the sump.
Check the physical condition of all components within the controller, insuring that all primary and secondary wiring and connections are clean and tighten as necessary. Look for indications of excessive heat, cracks, fractures or other visual signs of stress on the components and replace as necessary. Carefully note all settings and record any changes made to adjustable components.
Check the line side voltage supply to the controller for both single or three phase (1F or 3F) systems with the pump off. For three-phase (3F) systems check on and between all phases.
Check the load side voltage supply to the pump for three-phase (3F) systems on and between all phases with the pump on.
Check the amperage draw on all phases of either single or three-phase (1F or 3F) power with the pump on.
Before operating the pump, megger the pump while cool for moisture through the power cable at both the controller (and junction box, if used) and check and test, where applicable, all existent bearing, leakage or motor thermal sensors.
Test the operation of the system: first, force a “high level” alarm by turning pump off and wait for liquid level to rise, turn the pump to automatic and pump should come on because level is higher than the “pump on” level, and observe the pump shutting down at “pump off” at low level. Check any other operational functions such as tank interlocks, timers, redundant alarms or low-low level.
Readjust or replace any inoperative sensors or indicator bulbs. Check the transducer breather tube filter/drier and replace as necessary.
Check the system flowmeter for the capacity (Gallons Per Minute) and the system pressure gauge for the pressure (psi x 2.31 = Total Dynamic Head in feet). Compare to either the readings of the startup report or the previous scheduled inspection. If the capacity is less, it may mean a blocked impeller or inlet; if the pressure it less, it may mean impeller wear. Remember that both the flowmeter and pressure gauge can be subject to wear and tear, as well as the pump.
If all of the above are satisfactory and the pump is doing the job, the pump shouldn’t need to be pulled for physical inspection more than once a year.
Check the general condition and integrity of the station to include the riser accessories, exit fittings, covers, hatches, valves, meters, instrumentation that can be inspected. Note any changes from the previous inspection.
If the pump needs to be pulled, check the integrity of the retrieval system to include cable, fittings, fasteners and transport carriage or sledge, guide rails, sliding brackets and the discharge hose or pipe and any connections or fittings.
Check the power and sensor cables for abrasion and cuts, noting that neither should be spliced within the riser or wetwell. Clean and inspect any conductivity probes, liquid level floats, bubblers or transducers.
Check the pump for the effects of erosion, corrosion wear and tear, and blockage of the pump inlet. Unless the electrical readings, flow readings or pressure gauge indicate a motor problem or lack of pumping performance, the pump should not be torn down during a routine inspection.
|Ano da Publicação:||2004|
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