Abb ACS550 quick question on running %

[rooke]

Hey there, We have Multiple sewer lift stations using these drives. My boss would like to know what percent the pumps are set to run at curantly. The original set up was set to run at 50% for this perticular station. Since (and before my time here) The pumps have been set higher. So my question is, What peramater should i be looking at to find out what they are running at? Would it be max speed, torque or actually a percentage? Thanks in advance! There is just sooo many peramaters on theses drives and im an electrician with little PLC exp.

 

[DickDV]

If the ACS550 is anywheres close to default configuration then the frequency command is displayed in the upper right hand corner. The actual frequency is displayed on the top line of the center display with larger digits. Both would normally be in Hz. To get rpm you will need to convert Hz to rpm based upon the motor nameplate speed.

You can find the input frequency scaling in Group 11 parameter 04 (Min Freq) and parameter 05 (Max Freq). Normally, this max and min will be the range available.

If the actual available range is narrower than you see in 1104 and 1105, then go to Group 20 which is Drive Limits and check 2007 and 2008. These will control if narrower than the input scaling values in 1104 and 1105.

The bottom line on the keypad display is, by default, a readout of motor torque in % of full load. It is not speed or speed range.

On the longshot chance that these drives are set up in sensorless vector mode, the command speed and actual speed will be displayed in rpm rather than hz. If that is the case, come back to us here and I'll give you slightly different instructions.

 

[dmargineau]

It probably is Torque since it is a percentage of the motor's nominal.
Group 01, Parameter 05 (P0105) for the Operating Data (functional drive torque).
For the User Defined Limits (Application Settings)
Group 20, Parameter 15 (P2015- MIN TORQUE 1), Parameter 16 (P2016 -MIN TORQUE 2), Parameter 17 (P2017 -MAX TORQUE 1) and Parameter 18 (P2018 -MAX TORQUE 2).
Refer to:
http://www05.abb.com/global/scot/sc...3107/$file/EN_ACS550_01_UM_G_A4_ScreenRes.pdf

 

[rooke]

thank you for the responce.
name plate on pump is
3phase60Hz 7.5kw-10hp 1735RPM
The Original parameters in Group 20 were 2007:45 2008:46
So if im converting the Hz to RPM (and ive never had to do that so 60Hz x 60sec =3600rpm?) Then even at 45Hz Id be way over the faceplate value. Clearly im doing this wrong.
Those original parameters were in the ABB manual, id asume from the installer.

 

[rooke]

oh wait 1800rpm = 1hz@30rpm? so 45hz would be 1350rpm? i think

 

[balash]

yes that would be that rpm = round per minute => 1800 round per 600 sec so yes.
basicly:

frat : 60 = fx : nx => nx = (fx/frat)*60

 

[rooke]

Thanks to all for your help. As i start getting into the PLC side of this new position im sure ill be back for more!

 

[DickDV]

rooke, if Parameter 2007 was 45 and 2008 was 46, then you basically had a frequency range of 45 to 46hz---or no range at all. I would think that these should be opened up to maybe 20 and 50hz. Then go to 1104 and 1105 and set them narrower, if needed.

On a centrifugal pump, you want to be sure at maximum frequency, you aren't taking the motor into overload causing an eventual overload fault. And there isn't much point in letting the motor go below 20hz as a typical centrifugal pump doesn't do any useful work below that speed anyway.

Since your motor nameplate says 1735rpm, that would be the fullload speed (1800-65) at 60hz. 30hz would correspond to 900-65 = 835rpm at full load, and so forth. Of course, a centrifugal pump unloads rapidly as it slows down so you wouldn't see full motor slip of 65rpm as you reduce speed but, you get the idea.