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LW’s What is it? Three Phase Motor Starters 1 The coil connections on both NEMA and IEC motor starters are typically identified by the use of what letter and numbers? 2 The letter A and the numbers 1 and 2 This is an IEC diagram. The coil connections are identified as A-1 and A-2. 3 What protective element is missing from this motor starter? 4 The heater element for L-1 Notice the white insulated jumper 5 Where is the motor starter coil on this diagram? 6 This is the symbol for the motor starter coil The designer did not include the coil identification on this NEMA or American diagram. 7 How do you know when to stop tightening the screws on these heater elements? 8 When they become flat These washers have a slight cup to them. When they are properly torqued they flatten out. They are known as a disc spring or Belleville washers. When tightening fasteners it is recommended that you do so in three stages or lifts. 9 What is this? 10 This is an IEC overload relay assembly This is a Telemecanique brand overload relay assembly designed to IEC standards. 11 What is this and what does it provide? What do the letters H-1, H-3, H-2 and H-4 indicate? These two fuses protect what? What does this fuse protect? What do the letters X2 and X1 indicate? 12 This transformer provides control circuit power The letters H-1, H-3, H-2 and H-4 indicate the primary connections to the transformers These two fuses protect the primary of the transformer This fuse protects the secondary of the transformer The letters X2 and X1 indicate the secondary of the transformer 13 On this 500 HP motor what are these openings for? 14 These openings are for ventilation-cooling air 15 With the motor running where would you check for a voltage drop? What does this do? How many auxiliary contacts does this motor starter have? What is the voltage to this motor most likely? 16 Voltage drop is checked at L-1, L-2 and L-3 terminals This is a surge suppressor or an RC network. It suppresses voltage spikes. This motor starter has two auxiliary contacts. The colors brown, orange and yellow are typically used for 480V. 17 To replace the magnetic coil which four screws do you remove? To inspect the main power contacts which two screws do you remove? 18 To replace the magnetic coil you remove these four screws To inspect the main power contacts you remove these two screws 19 What is missing? 20 The overload heater elements are missing The wires that connect the motor starter to the motor are missing 21 With the motor running how could you check the condition of the main power contacts ? 22 With a voltmeter set to AC volts… Test from L-1 to T-1 Test from L-2 to T-2 Test from L-3 to T-3 If the voltage drop is more than 0.25 volts inspect the contacts for pitting and the springs for weakness 23 What is this and what does it do? 24 This is a Voltage Monitoring Relay This setting dial is for the under voltage. Range is 390 to 480 volts. This setting dial is for the over voltage. Range is 440 to 540 volts. This setting dial is for the time delay. Range is 1 to 30 seconds. 25 What is this? What terminal numbers are for the common connections? 26 This is a pneumatic timer The range is adjustable from 0.5 to 5 seconds The common connection on the left contact set is # 5. The common connection on the right contact set is # 6. 27 Two of these are ____ and one of these is a ____ 28 These two are contactors and this one is a motor starter The one with the overload relay is a motor starter 29 On a set of auxiliary contacts what do the following numbers indicate? 13 & 14 = 43 & 44 = 21 & 22 = 31 & 32 = 30 The numbers indicate the normal state of the contacts 13 & 14 = Normally open 43 & 44 = Normally open 21 & 22 = Normally closed 31 & 32 = Normally closed 31 All of the motor starters seen so far have been what type? I am not talking about brand name. How do they start the motor? 32 Across the line full voltage When a motor is started across the line full voltage it will draw between 5 and 8 times its rated load amps. 33 What two labels should be on the face of a motor starter enclosure? 34 An Arc Flash Warning and an ARC Flash PPE required label The upper WARNING label is required by the NEC. The lower Arc Flash and Shock Hazard label is required by NFPA 70-E the Standard for Electrical Safety in the Workplace. 35 Of the total cost of ownership what is the largest? Maintenance or Energy? 36 Electrical power accounts for 79% of the total installed cost of a motor over its life span Maintenance accounts for only 3% of the total installed cost of a motor over its service life. By improving the efficiency of a motor by 5% the total cost of maintenance can be completely offset! 37 As the horse power of a motor increases the maximum number of starts per hour increases or decreases? 38 As the horsepower of a motor increases the number of starts per hour decreases. Horse power Max Start/Hr. Min run time between starts in seconds ½ 24 120 ¾ 24 120 1 15 75 1.5 13 76 2 12 77 3 9 30 5 8 83 7.5 7 88 10 6 92 15 5 115 39 What are these individual parts known as? 40 These are the moveable contacts These are the contact springs These are the fixed contacts There are literally thousands of different types of contact sets. Many look very similar to each other. Replacement contacts must be ordered by starter brand size and model only. While replacement contact sets can be ordered for NEMA motor starters, typically they can not for IEC starters. 41 How would you describe these two coils? This is a paper wrapped coil. While replacement coils are available for NEMA starters, they are not for IEC starters. This is an epoxy molded coil. Most coils today are made using epoxy. They do a much better job of keeping chemicals, dust and moisture away from the copper winding. Some manufacturers use a color to indicate the voltage of the coil. Green indicates 230 VAC for this mfg. 42 What is this? 43 These are overload heater elements for NEMA motor starters The heater elements for IEC starters are not replaceable. The entire overload relay must be replaced. Overload heater elements have a part number on them. There are literally thousands of different types of heater elements. They must be ordered by brand, starter model and heater number only. 44 How are IEC listed starters different from NEMA starters? 45 IEC Starters have adjustable heater elements This element can be adjusted over a range of 1 to 1.9 amps. IEC listed starter overload relays can be set to either reset automatically or manually. There are several other differences not covered on this slide. IEC overload relay have two sets of auxiliary contacts that change state when the overload relay trips. Contacts 98-97 are NO and 95-96 are NC. NEMA overload relays have only one set of NC contacts. 46 Are these IEC or NEMA Motor Starters? 47 All of these are NEMA listed motor starters 48 Can you identify these connections? 49 These connections are to the pilot duty auxiliary contacts. They are NC. These connections are for the main power contacts. 50 In order to get the motor running again it is necessary to push the red button What does this most likely indicate? 51 In order to get the motor running again it is necessary to push the red button What does this most likely indicate? • The motor has been running with an excessive load • There is a significant voltage imbalance between the phases • Motor or driven load bearings are failing 52 The End Did you know all of the answers or close to all of them? Did you learn something? Is there some thing you would like to see added? Send me an email: [email protected] Work smarter… not harder! 53