4.Running

4.1 Check before starting

Attention should be paid to the following descriptions before starting .

  1. Distribution line

  Please check , against the power distribution diagram , the power supply , magnetic switch and other protective device , Star-Delta Starter , reactor , compensator , lead wires for space heater and thermometers , and the distribution line of other driven machines .

  1. Insulation Resistance

      Make sure the wire connections are well fastened or welded , their insulation is in good condition , and the terminals are properly spaced from each other .

  2. Grounding

      Check and make sure the frame or terminal box of the motor is grounded .

  3. Insulation Resistance

    1. To test the stator and rotor windings by their terminal connectors .

    2. Testing device of 500V be used to test stator windings below 3KV. Stator windings above 3KV be tested by 1000V device . All rotor windings by 500V device .

    3. Insulation resistance varies with rates output . and voltage . insulation classification and rpm of the motor . However , it also varies with the temperature , moisture , dust ridden condition , service period , testing voltage and testing period. Owing to the foregoing insulation resistance (R) can not be measured . However , the following rule will apply .

    3M ohm for rated voltage above 600V.

    1M ohm for rated voltage below 600V.

    or , formulae from JEC - 146 may apply ;

R¡Ù(rated voltage) /rated output(KW)+1000(M ohm)
R¡Ù¡a(rated voltage + rpm/3)  / rated output (KW) +2000¡b+ 0.5 (M ohm)

  1. In case insulation resistance becomes low , the winding s must be dried by hot air , by vacuum , or by electrical current (short circuit , low voltage when unloaded , and DC current ) as the situation dictates . In case resistance can not be brought up to desired level after drying , some defects may exist . Please locate and repair the defects . In case , the job can not be done , please contact Tatung company or its service station nearest to you .

  1. Lubrication

  Motors are well greased during assembly . However . it may be a very long time from the completion of assembly in our plant to the beginning of running in your factory ; it is necessary to make some replenishment . Tatung motors are greased with SHELL ALVANIA R3, when replenishment is made , please use the same or comparable products . For motors of special types , the specification and quantity of grease to be used are stipulated on respective nameplates.

  1. Check and make sure the coupled machine is in good condition . Coupling condition , tension of the belts and fastening devices should also be checked.

  2. Rotors of 2-pole motors or motors with roller bearings have often been locked during shipment , please make sure it can be rotated freely .

  3. Check and make sure there is no foreign body left in or get into the motor or its coupling machine during assembly or shipment .

4.2 Starting

  1. Starting load

  As a general rule , motors are started without load for test running . Only after being proved normal it can be coupled with driven machine for further test . Motors are usually started with light load and switched to full load after full seed is reached , except otherwise required .

  1. Direction of rotation-when viewing from non-drive end clockwise rotation is considered correct . After the terminal connectors U.V. and W (or 1,2 and 3) being connected to the connector R,S and T from power supply , the motor rotates  counter-clockwisely , interchange any 2 of the 3 connecting leads . Most motors can rotate both way . However , 2- or 4-pole motors with high rpm or 6-pole motors with large capacities , their direction of rotation has to be limited to either clockwise or counter-clockwise . In this case , a plate bearing an arrow to show the direction of rotation will be attached to the motor.

  1. Supplied voltage and current

  1. make sure supplied voltage agrees with or within ±10% of that shown on the nameplate . If the difference between rated voltage of the motor and supplied voltage , the windings may become overheated .

  2. Make sure supplied 3-phase voltages is in balanced condition among   phases. A little bit difference among them , unbalanced currents of considerable values may be resulted in .

  3. Make sure phase currents are balanced , otherwise windings will be exceedingly overheated and torque can not be provided. Sometimes , abnormal noise and severe vibration may be accompanied .

  1. Frequency

  The maximum variation between rated and supplied frequencies should be within 5% under  the rated voltage . If both voltage and frequency varies at the same time , the SUM of their absolute value should be within 10% .

  1. Starting

  In case the first starting is a failure , restarting can be made . However , as a principle , only two successive cold starting can be made at a time . If both efforts are failed , a 30 minutes interval should be allowed for primary and secondary conductors to get cold , which have been heated by starting current during these failed startings .

  1. Starting time and noise

  In case GD^2 of coupling machine is large , a longer starting time may required . However , if it is difficult to start or starting time is excessively long , and sever noise is noted during start , please contact Tatung or our nearby service activity .

  1. Vibration

  Determine the value of vibration with vibration meter or by feeling and compare that obtained with the data shown in Section 7 - Vibration . After this is completed, let the motor run alone. Then , run without load and then , run with full load . If nothing wrong during start , keep the motor running for 3 hours and take down the records every 15 minutes as stipulated below (5.2). In case nothing abnormal has been found , the motor will be kept on running and checks made every few hours. Still, there is nothing abnormal , the motor is considered serviceable and may be put into service .

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