Hi All,

first off apologies if this is posted in the wrong place!

I have an issue with a G120 drive. The load on the drive is a 30kW axial fan.

The fan attempts to start but gives up after a couple of seconds. Monitoring the BOP on start up I see a current draw but nothing excessive but no change in the speed rpm reading, it stays at 0. After a couple of seconds a black cross will flash on the BOP and starting will stop. No alarms are present on the BOP or in the history. Accessing online shows no alarms or alarms in its history.

I do not think the fan is free wheeling or counter rotating prior to start up but cannot be 100% certain as I cannot see the fan impellor easily. The fan is free and not seized. Bizarrely it will start sometimes and other times it wont.

Any help or advice greatly received and I can add any further info to help diagnose.

I have carried out an autotune, to no avail.

Rick

What is MLFB/article number of drive?

Which is CU?

Can you attach snap or video of BOP display status?

6SL32440BB121FA0 G120 CONTROL UNIT CU240E2PN

6SL32101PE260AL0 G120 PM240-2 22/30KW HO/LO 3PH

Not currently on site to be able to get a video of the BOP.

Hello,

Here I presume you are controlling drive via DI/DO of CU unit & not via bus.

Please go online with starter & check below points.

1. Control type is - [20] speed control (encoderless)

2. Check applied setpoint value & ON command. 

3. Check motor nameplate data & actual data entered in drive. 

4. Check torque limit values setting.

HTH

Try a test motor, connected directly to the drive?

Check the motor cable assembly, insulation and continuity.

Motor connection is this correct?

Tractor

Hi Piscean,

The drive is controlled via profinet

Control type is [2] U/F control with parabolic characteristics

Motor nameplate data is inputted correctly

Torque settings as follows:

p1520[0] Torque limit upper 311.62Nm

p1521[0] Torque limit lower -311.62Nm

r1538 Upper effective torque limit 318.47Nm

r1539 Lower effective torque limit -318.47Nm

P1610[0] Torque setppoint static (sensorless) 50%

P1611[0] Additional acceleration torque (sensorless) 30%

Will try a test motor if all else fails. 

Connections are good and correct.

Cable condition/insulation is all ok.

Fan was turned on on Monday afternoon, ran for over 24hrs till I stopped it to carry out some maintenance work. Would not restart. This has happened before, leaving it stood still for a few hours sometimes solves the problem and it will start up. On this last occasion it did not. Now away from site so cant try again until I go back.

Hello,

Next time, when such problem trugers, I suggest you to check setpoint value in r2050[1]. As you mentioned, no alarm or fault is displayed, ON command is trigered but fan does not rotate. So I guess, Control word, setpoint value might not be passed on to drive.

Please check above.