CATASTROPHIC OR FATAL ELECTRIC SHOCK MAY RESULT FROM FAILURE TO CONNECT THE MOTOR CONTROL ENCLOSURE, METAL PLUMBING, AND ALL OTHER METAL NEAR THE MOTOR OR CABLE, TO THE POWER SUPPLY GROUND TERMINAL USING WIRE NO SMALLER THAN THE CABLE WIRES. TO REDUCE THE RISK OF ELECTRICAL SHOCK, DISCONNECT POWER BEFORE WORKING ON OR AROUND THE WATER SYSTEM.
DO NOT USE IN SWIMMING AREAS
THIS EQUIPMENT IS INTENDED FOR INSTALLATION BY TECHNICALLY QUALIFIED PERSONNEL. FAILURE TO INSTALL IN COMPLIANCE WITH NATIONAL AND LOCAL CODES, AND SUBMERSIBLE MOTOR ENGINEERING RECOMMENDATIONS, MAY RESULT IN ELECTRIC SHOCK OR FIRE HAZARD, UNSATISFACTORY PERFORMANCE AND EQUIPMENT FAILURE. SUBMERSIBLE MOTOR ENGINEERING INSTALLATION INFORMATION IS AVAILABLE FROM PUMP MANUFACTURERS AND DISTRIBUTORS OR DIRECTLY FROM SUBMERSIBLE MOTOR ENGINEERING.
HANDLING AND INITIAL CHECKS
- Inspect the motor and leads for transport damage. Report any visible damage to the transport company and to your supplier immediately.
- Do not lift the motor using the lead wires. Do not pull the lead wires. The lead wires need to be protected at all times as damaged leads may allow water into the wires causing an Earth fault.
- Check the motor nameplate data and ensure that it matches your purchase order and meets your requirements.
- Motors are usually supplied with factory-installed water inside. This water has been mixed with antifreeze, which allows the motor to be stored in temperatures down to –30 deg. C. or –22 deg. F. If motors are to be transported or stored below these temperatures the water/antifreeze mixture must be drained from the motor. (We recommend that the motor be clearly tagged to alert future users that the motor has been drained).
- It is recommended that if motors are to be stored for a long period of time, that they be stored under water to ensure that the motor does not drain and dry out, which can lead to corrosion forming inside the motor.
- On new installations and if the motor has not been used for a long period it must be “Meggered” at 1000V prior to operation. The Megger reading / Insulation Resistance should be at least 1000 Mohms before operation and at least 50 Mohm when hot after running.
- Verify that the motor is full with water/antifreeze mixture or clean water prior to Installation. FAILURE TO ENSURE THAT THE MOTOR IS FULL OF WATER PRIOR TO OPERATION WILL VOID ANY WARRANTY CLAIMS. Ensure all filling plugs, drain plugs, cable connections, and mounting bolts are tight.
- The coupling should be a tight sliding fit on the shaft. Do not hammer or force the coupling onto the shaft as this could damage the Thrust bearing.
- Check that the rotor is free to turn by rotating it by hand. (Motors with mechanical seals may feel stiff when turned by hand).
- Make sure that the diaphragm opening at the bottom of the motor is open and not blocked with mud or dirt.
- If the motor is to be operated in the Horizontal SME must be advised prior to installation.
THIS MOTOR IS FITTED WITH 1, OR 4, PT100 TEMPERATURE SENSORS.
IT IS STRONGLY RECOMMENDED THAT THE PT100s ARE CONNECTED TO A TEMPERATURE DISPLAY DEVICE AND THAT 1, OR ALL 4, STEADY STATE TEMPERATURES ARE RECORDED WHEN THE MOTOR IS COMMISSIONED. THE PUMP SUPPLIER SHOULD BE ADVISED OF THE TEMPERATURES THAT ARE RECORDED AND THE CURRENT AND VOLTAGE. THERE IS A FORM “SUBMERSIBLE PUMP/MOTOR RECORD FORM” ATTACHED TO THIS DOCUMENT THAT WE STRONGLY SUGGEST IS FILLED IN ON A REGULAR BASIS.
IT IS RECOMMENDED THAT THE TEMPERATURE DISPLAY UNIT ALSO HAS A FUNCTION WHICH ALLOWS TEMPERATURE PROTECTION TO BE MONITORED AND SET FOR ALL 4 CHANNELS TO SHUT DOWN THE MOTOR IF TEMPERATURES INCREASE MORE THAN 3 DEG.C.
IF THERE IS A WARRANTY INSPECTION THE MOTOR MUST BE RETURNED TO THE ORIGINAL SUPPLIER, OR SME, WITH LEADS AND SPLICED JOINTS INTACT – AND THE CABLE MUST BE CUT ABOVE THE SPLICED JOINTS.
CHECK LIST PRIOR TO INSTALLATION
Please check the following:
- Ambient Temperature of the water to be pumped and ensure that it is less than the temperature rating of the motor.
- The PH of the water is between 6.5 and 8.
- Maximum Chlorine content in water is less than 500 PPM.
- Maximum Sulphuric Acid Iron content in the water is less than 15 PPM.
- Maximum Fluorine content in the water is less than 0.8 PPM.
- Maximum Sand content is less than 50 PPM.
- The electrical control equipment includes suitable fast acting current overload protection, which is set to shut the motor down within 3 seconds under locked rotor current or starting current conditions.
- The electrical control equipment includes suitable fuses or circuit breakers to disconnect the system if there is a fault.
- Variation of the supply voltage and frequency combination is within 5% of the motor nameplate voltage and frequency.
- Maximum voltage unbalance is less than 5%.
- The cable sizes are calculated to ensure that the voltage at the motor is still within 10% of the motor nameplate voltage after allowing for volt drop at full load current.
- Waterproof submersible type cables must be used with these motors.
- The motor has been correctly selected to suit the pump, thrust load from the pump, electrical supply capacity, and water availability from the well. The motor should be installed with at least 3 metres, (10 feet), between the bottom of the motor and the bottom of the well.
- The motor must always be immersed in water and the flow of water past the motor must be between 0.5 ft/sec, (15 cm/sec), and 10 ft/sec, (300 cm/sec). The water must flow freely past all sides of the motor. These motors will overheat and have a catastrophic failure very quickly if they do not have good water flow when they are running – even on No Load.
- Connection of the motor to an incorrect supply will void any warranty.
- Protection against single phasing is strongly recommended. If the motor fails due to single phasing the warranty will be void.
- Installation of Lighting Arrestors is also recommended to protect the control panel, motor cables, and the motor. Any failure due to lightening will not be covered by warranty.
- All cable joints must be done properly by technically competent technicians They must be waterproof and give a good electrical connection with no volt drop. (SME can supply a recommended procedure for splicing cable joints on request).
- Reduced voltage starting using Soft Starters, VVVF drives, Autotransformers, (or Star-Delta starters if the motor has been supplied with 6 leads out), can create additional problems for submersible motors. Please ensure compliance with the following points.
- The motor runs up to speed in less than 4 seconds.
- Correctly selected Quick Trip overloads or circuit breakers are correctly installed and correctly set to protect the motor.
- Suitable Short Circuit Protection is installed.
- The starter will allow the motor to generate sufficient torque to start the pump and run it up to speed. (In general the torque is reduced by the square of the voltage – a small reduction in voltage will lead to a large reduction in starting torque).
- Timers are set to ensure that the motor has enough voltage for enough time to run the motor up to speed as quickly as possible, and also switch the motor over to full voltage as quickly as possible and prolonged running at reduced voltage will stress the motor windings.
- Thrust bearings in submersible motors will not operate properly at low rotational speeds. It is very important to get the motor speed up to at least 500 rpm quickly to allow the thrust bearing to start operating properly. This is especially a potential problem for motors being started with Soft Starters or operating on VVVF drives.
COMMISSIONING and OPERATION
- After energising the motor for the first time, ensure that the starting current drops to below the nameplate current within 4 seconds, which means that the motor has run up to full speed. (If motor is being started with a Soft Starter or Auto-transformer the run-up must still be less than 4 seconds).
- Check the flow and pressure from the pump to make sure the motor is running in the correct direction of rotation. Swapping any 2 of the 3 phase supply leads can change the direction of rotation.
- While the motor is running for the first time check the water for sand. If sand appears continue to pump until the water clears. If the motor is switched off while the pump is still pumping sand this could accumulate in the pump and cause it to seize up.
- During testing or checking rotation the number of starts and the time between starts needs to be controlled. As a general rule the motor should be allowed 15 minutes to cool down between each start.
- All SME motors are fitted with one or more PT100s so the internal temperature can be monitored and this needs to be kept below 70 deg.C. on Standard Wet wound motors. The standard insulation wire can operate up to 80 deg.C., and the temperature inside the motor can vary between different parts of the motor. In general the hottest part of these motors is in the stator end winding.
- It is strongly recommended that the “Over Current” protection is set to trip at about 5% higher than the steady state current recorded when the motor/pump is commissioned. It is not recommended that the “Over Current” protection is set at just above Full Load Nameplate Current, as, in a lot of cases, this will not protect the motor if the current increases, especially if the motor is not fully loaded. We believe that the operator needs to know if the current starts to increase, so they can determine why.
- During the life of the Installation all Temperature, Voltages, Current and Insulation Level readings should be recorded, monitored and reviewed as a form of preventative maintenance.
There are no ball bearings that need oil or grease. The motor cannot be accessed unless it is removed from the well, so everything that can be monitored needs to be monitored on a regular basis, and any unexplained changes investigated.
- The normal running temperatures, current and voltage on all 3 phases needs to be recorded on a regular basis.
- The motor winding and the drop cable insulation needs to recorded on a regular basis with reference to the temperature of the motor – hot or cold – if the motor does not have temperature monitoring installed. If the cold insulation drops below 50 Megohms the installation needs to carefully checked out.
- The output pressure and flow from the pump should also be monitored on a regular basis.
- The overall performance of the pump and motor and the well can be reviewed based on the information being recorded and this can be used to determine any need for maintenance or overhauling, which might be required.
- SME have a separate brochure, which details how to carry out maintenance on the motor including strip down, inspection, and re-assembly.