“Check the equipment prior to storage to anticipate any possible problems at the time of installation. You can minimize installation problems by checking sizes, design features called for on the plans and specifications and all interface components”

The proper installation of a submersible wet well pumping station involves careful coordination from planning through completion. Deliveries must be scheduled and checked. All accessories must be installed in accordance with the job specifications and the manufacturers’ instructions. Electrical control panels must be installed and tested with care. When start-up is accomplished properly, the specifier, operator and owner can be assured of trouble-free operation. Careful preparation and planning is needed to ensure proper installation of all equipment in submersible sewage pumping stations. There must be effective coordination between the supervising engineer, the mechanical and electrical contractors, and all suppliers.
The first step is to ensure that the required station equipment is ordered completely and accurately according to specifications, and that—considering lead times—all of it will arrive prior to the scheduled installation. This includes not only the pump and electrical control panel, but the station itself (if prefabricated) and all accessories, such as piping, valves and access covers.

Receipt and Inspection
All equipment should be examined upon receipt for any signs of apparent damage. If there is damage, a claim should be filed immediately with the carrier and the supplier should be notified. All parts shipped loose or separately should be checked for loss or damage.
If the equipment won’t be installed immediately, it is best to store it in a clean, dry location where it will be protected from possible damage. Follow the manufacturer’s recommendations and protect equipment from low temperatures or freezing. Check the equipment prior to storage to anticipate any possible problems at the time of installation. You can minimize installation problems by checking sizes, design features called for on the plans and specifications and all interface components.

Handling Pumps
“A submersible pump should be transported and stored in accordance with the manufacturer’s recommendations”
Make sure that it cannot roll or fall over. Always lift the pump by its carrying handle, never by the motor cable.
In the absence of specific manufacturer recommendations about storage, pumps must be protected against excessive moisture and heat. This precaution is necessary to prevent moisture damage to internal components and the power cord, etc. The impeller should be rotated by hand occasionally (for example, every other month) to ensure free movement of the rotating elements. The cable entry seal must conform to the outside diameter of the cable to prevent leakage into the pump.
The end of the power cable must not be submerged, as water may wick through the cable into the motor.
After any period of storage, the pump should be inspected, tested and/or reconditioned in accordance with the manufacturer’s recommendations before it is put into operation.

Pump Station Installation
When beginning the installation, ensure that all equipment is on site and that all manufacturer instructional literature is available, has been reviewed and is followed.
In addition to the pump(s), the following items are typically required:
• Discharge elbow/support base and/or sealing arrangement for connecting the pump to the discharge line.
• Guide rail(s) consisting of specified material and size.
• Upper guide rail brackets for attaching the rail(s) to the access cover frame or top of the station.
• Intermediate guide rail supports as required.
• Specified discharge piping and fittings.
• The proper check and shut-off valves.
• Level sensor or other control equipment.
• Cable holder for level sensors or other sensor brackets.
• Junction box or conduit box (if required).
• Access frame (with covers).
• Control panel.

Access Cover Installation
There are two common installation methods for access covers. One is to cast the unit into the poured concrete slab well cover. The other method is to frame flange the unit and drop it into the steel well cover.
Both types of installation must align properly with the baseplate. Prior to casting the door unit into concrete, the cover should be closed and checked to make certain that it rests on the frame all around. Shim the frame as necessary to ensure proper door closure. Remember that aluminum frames must be protected from the wet concrete by a bituminous coating.

Internal Assembly
Now that the access cover is in the proper position, you can begin to install the internal station components.
Place the pump discharge connection in position. Temporarily secure the guide rail(s) in the upper mounting brackets and the discharge bosses at the bottom. Install the intermediate support brackets, if required. Ensure the rails are in a true vertical position, so the pump will clear the access opening and slide freely down the rails into place in the discharge connection.
Once the rails are in proper alignment, bolt the discharge connection into the floor of the station. Connect the discharge pipe to the discharge connection and proceed to install the check valve, shutoff valve and fittings according to the plans and specifications.
All level-sensing devices must be properly secured to the access cover frame or the wet well. Install them at the levels indicated on the plans and specifications. Control components, other than level-sensing devices, should not be installed in the wet well.
Lifting equipment is normally required for handling pumps. It should be able to hoist a pump straight up and down in the station, preferably without having to reset the lifting hook. Make certain the lifting equipment is securely anchored. Keep all personnel out from under suspended loads.
Before lowering a pump into place, it must be checked for correct rotation, using one of the following methods:
1. Prior to installation in the wet well, lay the pump on its side and momentarily run (jog) and check it for rotation. When running the pump outside the wet well, care must be taken to stay clear of the impeller and to provide a safe, temporary connection of the motor leads. The best procedure is to lift the pump with a hoist or tilt it slightly and observe the rotation. An arrow on the pump casting, or instructions in the Pump Instruction and Operation Manual (IOM), will show the proper
direction of rotation. This is the most accurate method to test for proper rotation; however, other methods are
usually provided as a secondary check or for circumstances when the pump cannot be lifted from the station.
2. After installation, if the check valve has an external operating arm, you should be able to see which rotation of the motor opens the check valve widest. This indicates the higher flows, and is the correct rotation for the pump.
3. If pressure taps are available, rotation can be ascertained by reading the shut-off head on a pressure gauge. The proper rotation will produce the higher pressure.
4. The least desirable procedure is to position the pump in the hand mode, using the Hand-Off-Automatic (HOA) switch, lower it to the bottom of the wet well, and check the drop in water level in the well. The rotation resulting in the faster drawdown is the proper rotation.
Use the above procedures before start-up of the station. Keep in mind that visual inspection of the rotating elements is the most accurate method.
The direction of rotation on three-phase pumps may be changed by interchanging any two motor leads at their control panel connections. For single-phase pumps, if improper rotation is observed, consult the IOM or contact the pump manufacturer.
After the proper rotation is verified, lower the pump along the guide rail(s). Upon reaching its bottom position, it should automatically connect to the discharge. Adjust as required, following the manufacturer’s recommendations.
Fasten the lifting chain on the access frame eyebolt and fasten the cables on the cable holder. Cable supports are required for deep installations. Run the pump and level control cables up to the electric control panel or into the junction box, if used.
The pump and level control cables should be long enough to reach the control panel without splicing. If a junction box, conduit box or quick connector plugs are utilized, they should be located outside the wet well—or, if located in the wet well, be of at least NEMA Type 4 construction.
It is highly recommended that conduit seal-offs be located between the wet well and the control panel to prevent gas migration into the control panel enclosure.
Arrange for a cable, if needed, between the sump and the electrical control panel. Make sure the cables are not sharply bent or pinched, and that all connections are sealed and watertight to prevent leakage from ground water.

Control Panels
Before making a new installation, a qualified electrician or factory service technician should verify the horsepower, voltage rating and full load amperage of each pump. This information should be used to ensure that the control panel is of the correct horsepower, and that the heater coils furnished in each motor starter overload unit are sized or set correctly to match the motor’s operating current as given on the motor nameplate.
The service voltage and frequency should be checked to ensure they are the same as the motor rating. This information should be used to cross-check the circuit breakers, fuse or disconnect ratings. All electrical work must comply with national and local codes and regulations.
At the time of installation, the panel or equipment should be checked for missing or loose components—including a correct wiring diagram. All wire terminations should be checked for tightness. Care must be taken in handling the control panel and equipment during installation to avoid damage to the enclosure or any of its components.
Location and provisions for mounting the panel should be shown on the plans for the job. Make certain the enclosure is the type specified for that particular location. Adequate racks, mounting brackets, and fastening hardware must be used to securely mount the panels and devices.
On flat surfaces, panels should have a slight clearance between the back of the panel and the mounting surface to enable air circulation. While clearance is usually provided by the enclosure design, it may need to be furnished by mounting hardware. This ensures heat dissipation and prevents moisture accumulation.
If the panel is mounted on a rack, it must be constructed and braced to provide a flat, rigid surface that will not distort the panel and cause possible door alignment problems.
Mounting bolts and hardware must be of sufficient size to provide stable positioning and of materials suitable for the operating environment.

Field Wiring
All conduits and wires must be installed as required on the plans for the specific job. All cable entrances into the enclosure must be in accordance with the NEC, and shall maintain the integrity of the NEMA enclosure, to prevent intrusion of moisture, dust and gas vapors. When possible, conduits should be attached from the bottom of the enclosure to facilitate weatherproofing. Weatherproof hubs and sealed fittings should be used.
The size of conduits and wires must be adequate for the specific requirements of the incoming service, pump motor leads and remote control devices. The NEC must be used as a minimum guideline.
After the installation of the conduit and wiring, make certain that all terminations in the control panel conform to the panel manufacturer’s diagrams and instructions. The incoming service voltage must be correct for the panel. Typically, three-phase systems are designed for a 208, 240, 480, or 575 volt, four-wire service voltage. Single phase systems are most often 208 or 240 volt, two- or three-wire, but are sometimes 120-volt, two-wire service voltage.
As a safety precaution, before connecting the motor leads to the control panel or applying power to the pump, take and record megohm readings with a 500-volt megger. Connect all motor leads together and check the combination to ground. The readings should be above 20 megohms at all points. A motor should not be run if any reading is below 10 megohms. If this is the case, find and correct the source of the low readings. If the readings are between 10 and 20 megohms, the pump should be run for short periods and the readings rechecked. Only after tests are complete should the motor leads be connected permanently to the control panel.
The pump leads must now be connected to the control panel following the panel diagram, using the pump manufacturer’s wiring diagram to distinguish and verify the connection and color coding of the leads. Internal pump/motor safety controls should be identified following the pump manufacturer’s wiring diagram and connected to the panel as specified by the panel manufacturer. Make certain the pump is correctly grounded.
If automatic control of the pumps is provided by liquid level sensors in the wet well, all connections must be made to the proper terminal points in the control panel. Care must be taken to identify each sensor and its specific function. Proper connections ensure sequential and automatic operation of the pumps.
Wires must be marked to provide future identification should re-connection be required during maintenance or troubleshooting. A record should be made in the permanent file for the control panel regarding field wire connections, wire sizes and types, cable lengths and any other related information. This file can be valuable during normal maintenance, for emergency situations and as a reference for future installations.
When incoming service voltage is available and the system is complete and ready to be put into service, a qualified electrician should be present. If the service voltage is 240-volt, three-phase, four-wire from Delta-connected transformers, the "high line" must be identified; it has a higher than 120 volt (usually about 210 volt) reading phase to neutral. The control panel must then be checked to make certain no control circuits or 120 volt operating devices are connected to this incoming high line.
Some local codes require that the high line be on a particular phase connection, usually Phase B or sometimes Phase C. (Consult local codes to determine if there is such a requirement in your area.) Most control panels are designed to use Phase A for all 120 volt phase to neutral circuits when no control transformer is used.

Start-Up and Testing
Many pump and panel manufacturers have special forms that can be used during the start-up of the station (Figs. 1 and 2). Some manufacturers require that these forms be filled out and returned to ensure warranty on the pumps, control panels and station components. This type of form provides a detailed description of the procedures and tests to be performed. Following is a summary of these procedures.
The panel is ready to be put into service after the incoming service voltage has been checked on the line side of the main circuit breaker or disconnect, and it is verified that all phases and neutral (if used) are present and at acceptable levels.
All circuit breakers and selector switches must be in the off position. The main circuit breaker or disconnect can then be turned on. One at a time, each of the other circuit breakers should be turned on, to check the load side of each for correct voltage. This includes the control circuit.
With sufficient water in the well, turn each pump operating selector switch Hand-Off-Automatic (HOA) to the hand position to run each pump. Take and record amperage readings on each motor lead with a clamp-on ammeter. The phase-to-phase voltage must be checked and recorded at this time. If there is excessive amperage draw on one leg, start troubleshooting by checking the manufacturer’s recommendations. Consult with the power company only after all other checks have been made.
The initial readings for amperage, voltage and ohmmeter resistance, plus megohm readings, should be the start of a permanent maintenance file. Monthly, quarterly or annual readings should be taken as part of a good preventive maintenance program. They are the basis for scheduled checks, which can indicate the trend of the motor current draw and can help prevent major outages and costly motor rewind jobs.

Operational Checks
When start-up and testing is completed, the system is ready to be checked for automatic operation. Both or all of the pump operating selector switches should be turned to the auto position, and the alarms turned on or reset as required for normal operation.
The best way to check and correctly set the on and off levels is to provide an external water supply source to fill the wet well to various predetermined levels. This water can be from a nearby hydrant or other source. Care should be taken when discharging water into the wet well not to affect floats or other controls. By controlling the fill and then observing or setting the operating points, the automatic cycle or cycles of operation can be checked, no matter what type of level controls are employed.
To achieve second and/or subsequent pump start levels, the circuit breaker or disconnect can be turned off for the lead pump. This enables the wet well to fill, without running the lead pump, to the lag pump on level for checkout.
All pumps may be turned off to enable checking and testing of alarm levels. The pumps should be permitted to pump, to allow checking of the desired off level. If a low alarm level is included below the normal off level, a pump may have to be run in the hand mode to check it. If guaranteed submergence with redundant low water cutoff is specified, it should be checked to be sure the wiring has eliminated the possibility of hand operation. The control system should be cycled more than once to check the proper and automatic alternation sequence of the pumps. If the panel is supplied with a manual alternator switch, it should be operated and the pumps cycled again to check for sequencing. Each run cycle, after alternation, should be checked to run both lead, lag and any subsequent pumps to ensure complete, correct alternation of the duty cycle.

Simulation Testing
Simulation testing should be done only in those extreme cases where sufficient water is not available and the pump(s) cannot be run in the well. Because the pump(s) are not run and the actual well water level is not used to energize the level sensing devices, the procedure is not recommended.

Other Checks
During the check-out of control systems, check the pump run pilot light indicators, elapsed time meters and any other associated controls for proper operation. The alarm levels, when activated, should operate all devices in the system. These can include an alarm light, pilot light, audible horn or bell and a relay to provide remote signal contacts or telemetering contacts.
All the alarm devices should be checked for proper operation, including audible alarm silencing circuits or switches and any reset pushbutton, if used.
If any special control or alarm
features are included in the system, they should be checked by simulation if actual conditions cannot be achieved. These may include seal failure indicators, motor thermal sensors or telemetered incoming or outgoing signals.
Another device often used and not always checked is the phase monitor. Most have three functions: loss or low voltage on a single phase, loss or low voltage on all three phases, and phase rotation reversal.
By turning off the service voltage to the panel, disconnecting one of the sensing leads to the phase monitor, and then insulating it when the power is turned back on to the panel, the pumps should not operate in either the hand or automatic mode. Reversing the above procedure, the lead should then be reconnected. This will check the loss of a single phase feature.
On some units, if the service nominal voltage is low enough, the set point on the monitor can be raised sufficiently above nominal voltage to cause the running pump or pumps to drop out. This will check the three phase low voltage setting of the phase monitor.
By turning off the service voltage and reversing two of the sensing leads on the phase monitor (to induce improper rotation), and then restoring the service voltage, the pumps should not operate in either the hand or automatic mode. Reversing the above procedure, the leads should then be reconnected. This will check the phase reversal feature of the phase monitor.
These checks are important, since they offer the protection needed during normal operation of the system. The last is important if the service is ever disconnected and reconnected, to prevent the pumps from being run in reverse rotation. If a station is provided with a power plug for the use of a portable standby generator, this reverse phase feature is essential to ensure that the generator phase rotation is matched with the normal service phase rotation.

Final Tests
After the above tests have been completed, the panel should be thoroughly checked to ensure that all wires have been reconnected properly, all switches or jumpers used for simulations have been removed, and all circuits restored to normal operation.
With the service voltage turned off, all wire terminations should be rechecked for tightness and the panel cleaned to ensure a good, maintainable environment. The panel should now be ready for continuous automatic operation.
The run time on elapsed time meters should be read and recorded for each pump. These readings should be the start of a permanent maintenance file. Periodic readings should be taken and recorded as part of a good preventive maintenance program.
With these readings, the alternating duty cycles can be checked to ensure operation of the alternator. Many pump and motor maintenance schedules are based on hours of operation. Actual automatic cycles are monitored to be sure they are not excessive. For submersible motors, a maximum of 10 to 15 starts per hour are acceptable in terms of equipment life.
Over a period of time, this record may show system demand trends and indicate the need for larger pumps. By calculating the pumping rate of each pump and the hours of run time, the gallons of water pumped for a given time period can be estimated. This can indicate problems with increased water infiltration into the system due to cracked or broken lines, based on an increase in gallons pumped with no other substantial changes within the system.
Make periodic checks during the first few days of operation of a new system. This can uncover unforeseen problems and help the operator become familiar with duty cycles and other characteristics of the pumping station. This special attention can help avoid future problems.

Source – Engineering Review
For any further queries with reference to the article write to shirish@engrreview.com