Fault and maintenance of the hottest motor soft st

2022-08-17
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Faults and maintenance of motor soft starter qb3 and qb4

(I) common faults and treatment methods

common faults and treatment methods of qb3 and qb4 are similar, as listed in the table

table Otto soft starter qb3 Qb4 common faults and treatment methods

fault phenomenon fault cause treatment method after power on, the power light is not on, the external power supply is not connected, check the power control board fault, replace the control board, the starting light is not on after starting, 13 and 14 terminals are not added with the starting signal, and the control board is faulty, replace the control board, start and terminate the soft starter protection, check the protection type, the starting signal disappears, check the 13 and 14 terminals, and repair the soft starter fault, and the soft starter is missing Phase protection power supply phase failure inspection power supply short circuit protection bypass contactor is not completely disconnected maintenance bypass contactor motor phase failure maintenance motor and its connection thyristor short circuit replacement thyristor filter board breakdown short circuit replacement filter board overheat protection after starting is not bypassed inspection bypass contact and its circuit start too frequently extend the starting interval fan damage replacement fan continued table

fault phenomenon troubleshooting Thermal relay action thermal relay setting value is too small. Increase the setting value. When starting, the motor current fluctuates greatly. Current transformer fault replacement current transformer control board fault replacement control board bypass contactor does not act. Peripheral circuit fault inspection peripheral circuit control board fault replacement control board bypass trip bypass contactor and soft starter phase sequence are inconsistent. Check the wiring bypass. After the contactor jumps off the bypass contactor, it cannot protect itself. Check the line thermal relay Electrical protection check protection reason: the starting time is very short and the protection starting voltage is too high. Reduce the starting voltage and the starting time is too short. Increase the starting time (II) fault protection of soft starter

fault protection of soft starter is shown in the table

table qb3 fault protection of soft starter

fault name fault indicator fault description fault cause power supply phase loss phase loss soft starter power supply phase loss power supply, wiring thyristor short circuit fault thyristor breakdown short circuit overvoltage, overcurrent overcurrent overcurrent starting current more than 5 times the rated current of the motor, excessive load, mechanical fault thyristor overheating, thyristor radiator temperature more than 65 ℃, frequent starting No bypass start timeout fault start time exceeds the set value, not switched to the running state, excessive load, mechanical fault memory fault memory data error hardware fault, program fault load phase failure fault load not connected or load phase failure load table qb4 fault protection of soft starter

fault name fault display fault description fault cause phase failure of soft starter power supply phase failure of power supply Wiring thyristor short circuit SCR short thyristor breakdown short circuit or load phase loss overvoltage, overcurrent, load phase loss overcurrent over current starting current is more than 5 times the rated current of the motor, the load is too large, mechanical fault thyristor overheating ror thyristor radiator temperature exceeds 65 ℃, frequent starting, no bypass starting timeout time is up, the starting time exceeds the set value, not switched to the running state, the load is too large, mechanical fault The starting time setting is too small, memory fault EEPROM error memory data error hardware fault, program fault (III) soft starter fault protection action

1 Action

after the soft starter enters the fault protection state, the following three actions are completed at the same time. It also plays a variety of roles such as dragging, straightening and stabilizing tension; Roller type (divided into horizontal type and vertical type)

(1) stop starting and close controllable

(2) fault relay action

(3) the corresponding fault indicator light is on

2. Reset

even if the cause of the fault is eliminated, the soft starter still maintains the fault protection state. The control power supply of the soft starter must be powered off and then powered on again to restore the normal working state of 2.2 weight measurement method

(IV) daily maintenance and simultaneous care

1 Dust removal

if there is too much dust, the insulation grade of the soft starter will be reduced, which may make the soft starter unable to work normally

(1) primary circuit creepage, arcing, endangering equipment

(2) secondary circuit leakage, short circuit, control failure

(3) the thermal resistance of the radiator increases and the temperature rise of the thyristor increases

methods for cleaning dust:

(1) gently brush off the dust with a clean and dry brush

(2) blow away the dust with compressed air

2. Drying of condensation

If condensation occurs, the insulation grade of the soft starter will be reduced, which may make the soft starter unable to work normally

(1) primary circuit creepage, arcing, endangering equipment

(2) secondary circuit leakage, short circuit, control failure

(3) aggravate the corrosion of metal parts

drying method:

(1) drying with electric hair dryer or electric stove

(2) dehumidifier can be used to dehumidify the distribution room

3. Replacement of fan

if the fan is damaged, the thermal resistance of the radiator will be increased, and the temperature rise of the thyristor will be increased. Long term operation will damage the thyristor

replace the fan

(11 is to strengthen the transportation of solid materials) replace it by itself

(2) contact the supplier

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