?> One V20 drive to two (parallel) motors

Hi.

We need to connect x1 Sinamics V20 drive
to power x2 identical motors at the same time.

DRIVE _____ OVL1 _________ M1
                  |
                  |__ OVL2 _________ M2

We have done so with other brands before.  On other brands we had to deactivate the drive's overload trip - for example. Also each motor has its own (external) thermal overload to protect the motor.

What I do not know is if there are any special settings to set to make the drive able to handle parallel driving of the x2 motors.

Thank you for your attention.
w

TechTeam

Hello William

Yes this is possible

please consider the following FAQ which is wirtten for Micromaster but can be applied to V20 as well:

https://support.industry.siemens.com/cs/de/en/view/14390055

Thank you for answering.
Could you PLEASE review your link as it pages to "SINAMICS Startdrive".

EDIT: I have found the information at...
https://support.industry.siemens.com/cs/ww/en/view/14390055

or German version at..
https://support.industry.siemens.com/cs/de/de/view/14390055

The English version has the same article ID number as you suggested but format looks a little different. Some Siemens database issue perhaps? I will work through the application note... thank you!

Several important points to consider.

- Make sure maximum cable length is not exceeded. (length of motor 1 + motor 2 cables).
- There must be a separate overload relay and contactor for each motor. An MSP would work also.
- The contactors must be closed before the drive starts.  I don't remember if the V20 has input contactor control.  You can probably use this signal for the output contactors.
- If a contactor opens under load, the Pulse Enable MUST be removed.  Normally the contactor closed signals are put in series as part of the Pulse Enable string.  You can blow the drive up if this does not happen.
- Set up the drive as if you have one big motor (don't disable the overcurrent protection, make it 2x one motor).
- Use V/Hz mode.  SVC is theoretically possible if the motors are rigidly coupled together.

Jeff Casagrande

Several important points to consider.

- Make sure maximum cable length is not exceeded. (length of motor 1 + motor 2 cables).
- There must be a separate overload relay and contactor for each motor. An MSP would work also.
- The contactors must be closed before the drive starts.  I don't remember if the V20 has input contactor control.  You can probably use this signal for the output contactors.
- If a contactor opens under load, the Pulse Enable MUST be removed.  Normally the contactor closed signals are put in series as part of the Pulse Enable string.  You can blow the drive up if this does not happen.
- Set up the drive as if you have one big motor (don't disable the overcurrent protection, make it 2x one motor).
- Use V/Hz mode.  SVC is theoretically possible if the motors are rigidly coupled together.

Thank you Jeff for your valuable notes.

(smile) It is not the 1st time we do this configuration...
just the first time the V20 is used in this way.
(Siemens brand was asked by the customer.)
All your concerns was already part of our design.

Just for your information.. we always run both motors.
Therefore we have an overload for each motor but no contactors.

Void of sarcasm - truly my thanks.
w

Hi dear William 

It's been a long time since you posted this issue

So I'm interested about it. 

Did you solved your problem?

How?

A couple weeks ago I had a similar problem but with Sinamics G120, the solution was connect an output reactor...

What about you??

Best Regards. 

Typical for, poultry shed, indoor animal accommodation ventilation, to roller table for steel mills, and textile installations.

Operating a number of motors from one inverter drive is easy until the total cable length is measured, it is the loss within an extended cable length between inverter drive and motor which creates the intermittent over current tripping. It is therefore necessary, to have the maximum cable length for the inverter drive available.

Be aware that the cable limits for Sinamics G120 devices can vary according to design, check this during the planning stage, afterwards this can cause some anxiety.......

Output chokes can extend the cable length, by reducing the dv/dt of the supply to the motor, but there are limits to this.

Sinus filters, these combine an output reactor with capacitors, in an attempt to convert the PWM output of the inverter into a sinus Voltage and current supply, but limits exist for this option. Here the losses are significant, and the acoustic noise can be alarming during commissioning and operation.