Dear Sirs,

I need expert advice to build a merchandise lift application using ACS 550 inverter. I asked the ABB representative and they told me that only ACS 800 can be used for that type of application, which I cannot believe. And my problem is that I already have 6 ACS 550 inverters for this application. I looked into the User Manual and I saw that an external relay can be programmed to energize when the motor current is reaching the level for which the rated torque is available and I'm thinking that this feature can be used to control the electro-mechanical motor brake.

Anyone more experienced??

Thanks!

 

If you use a worm gearbox that cannot be back driven, then your project will be much simpler. The problem is that only closed loop vector AC drives have good torque control at zero speed. Without a gearbox, you need the drive to hold the weight at rest.

 

You would be better off with the ACS 350, as that has inherent brake timing logic. I would try to use the relay out based on "Flux Ready", option 33. What mode are you using this in? What speed range do you want? Are you using an encoder?