Any Yaskawa drive experts here?

[Ronnie Sullivan]

I'm trying to set up a Yaskawa GA500 inverter to do multi- speed stage start up.
I only want 3 stages.

On run, ramp to 15HZ, wait n seconds to allow amps to come down
ramp to 30HZ, wait n seconds. Ramp to 43HZ. Run until turned off.

I want the time from zero speed to full to be about 40 seconds.
By doing a normal slow ramp up - the amps stay too high for too long and gives an overload fault.
If I do it manually via the keypad in the sequence above it always gets to the required speed.
The drive is capable of multi stage speed up but the technical manual is very complicated to understand. (or it's me)

It's a 22KW-30KW drive with a 22KW motor.
It's driving a centrifugal device like a spin dryer that expels water from a product.

 

[Ronnie Sullivan]

With it being an 800-page manual, and a very good but very complicated drive - I took to YouTube.
In the whole of Youtube there was only one video on multi-stepping the GA500.
A very nice Polish man explained and showed it perfectly.
It still took some time to ram it in my skull - but it's now working as I wanted.

 

[widelto]

Ronnie:
Maybe I am late but but What I have done in the past to start a centrifugal unit is to go from zero to max speed in 10 or 12 minutes in just one step, the same to turn it off.
The only two parameters that need to be modified are accel and decel time.

 

[Ronnie Sullivan]

I tried upping and upping the acc time and lowering the HZ increments but there is 5 tons of sopping wet, freshly dyed yarn in there.
Plus they need it to be at full speed for most of the cycle to drive out the water from the center. (which ironically is 12 minutes)
I tested it by running the cycle and upping the HZ manually while watching the Amps.

As they came down to 16A (from 60A) I manually upped the speed to the next setting.
I then replicated that on the controlling plc that luckily had spare outputs.

The problem was - the inverter has 12 programable inputs to do what you want with them but working out from the manual which parameters and functions I needed was a nightmare to work out.

 

[GaryS]

Read the manual
By default it drive is setup to do waht you want
multi speed referance
actually would use torque limit to control the amps on start up much cleaner and simpler

 

[Manglemender]

Read the manual
By default it drive is setup to do waht you want
multi speed referance
actually would use torque limit to control the amps on start up much cleaner and simpler

Accel at torque limit would be the way to go I think. We buy in Vacuum pumps from Leybold and the booster pumps (roots blower) always accelerate at torque limit. I'm pretty sure they have Yaskawa drives but i'm not sure how you set it that way.

Nick