elevator control problem with Schnieder inverter

A

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Anonymous

we are repairing with this old elevator for quite some time already, old controls were replaced with new ones... we have bought a schnieder 7.5 kw inverter to control the motor (5.5kw) speed going up and down...

problems encoutered were:

1) when the elevator cab is loaded, motor tends to loose its strength than when elevator cab is empty.

- we suspect that inverter needed a brake resistor as per previous experience however new problem arose...

2) inverter would display Ocr (Over current) after running the elevator sometime

- dc braking was used

3) everytime we have to power up the inverter a nSt (not set) will always be displayed... we have to remove L1 and then replace it again for the inverter to go to ready position... (we can't be doing this everytime)...
 
Firstly, check the motor parameters because your motor is 5.5kw & inverter is 7.5 kw. So ensure the parameter of motor.

DBR may be the solution of over current.
Follow the operating manual of drive & find out the cause & remides of the display massage.
 
hi.........

--A-- for gaining extra strength in elevator performance there is 2 solutions

-1- change the current drive with another higher kw drive e.g. 9 kw and this sol. is expensive.

-2- if there change the compensating chain with a heavier one.

--B-- for the over current , disable dc injection bracking , and if u r using the r2c contact for bracking then reduce the machine rpm parameter from the drive setting until you here the brakes released just as soon as a move ordered has been issued
 
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