Help design for hoist using G120 SINAMICS PM240

Dear Expert

I'm using SINAMICS G120 PM240 power module to design for hoist.

The first one (45KW) I'm using one drive for two application of movement (travel + rotate) as my picture ? Is there any problem here ?

http://i65.tinypic.com/1zn0d2p.jpg

The second one (75KW) Im using for hoisting

PM240 (with line filter + breaking resistor ) -> reactor output -> Motor. Is there any problem with the middle reactor between motor and power module in the hoisting application ?

Thank in advandce !

In your first picture, you are not showing any motor overload protection.  Each motor should have an overload relay.  This complicates things since you also need to ensure that the relay/contactors never open under load, so your EP switching can get complicated.

For both, why do you feel you need output reactors?  Are your cable lengths long?

For your hoist, I hope the braking resistor and brake circuit are sufficient.  I would use a PM260, but that's just me.  A crane spends 50% of its time braking, which is just lost energy now.

 Dear Jeff Casagrande

You mean :

Line filter -> PM240 -> Contactor -> Overload relay-> reactor (depend on length of the cable)->motor ?

Why we need overload relay while we can config current limit on CU ?

About length of the cable within 30m so we can not using reactor right ?

Thank you !

Jeff Casagrande

In your first picture, you are not showing any motor overload protection.  Each motor should have an overload relay.  This complicates things since you also need to ensure that the relay/contactors never open under load, so your EP switching can get complicated.

For both, why do you feel you need output reactors?  Are your cable lengths long?

For your hoist, I hope the braking resistor and brake circuit are sufficient.  I would use a PM260, but that's just me.  A crane spends 50% of its time braking, which is just lost energy now.

First, for line reactors.  Line reactors should be used if the TOTAL cable length exceeds 50m for shielded cable and 100m for unshielded.  The reactor, if used,  should always be attached to the output of the drive before any other component.

In the case where you have two motors connected in parallel, the drive overcurrent protection (it sees the current of both motors) can no longer protect the individual motors.  In this case, separate overload relays should be used.

In all cases, your output contactors should never open under load.  You will damage the drive if this happens.

 Thank Jeff

Do you have any method to protect drive if the contactor open under load suddenly ? May be i use a ATS Schneider to switch two application motor ?

Do I need to buy one more drive to separate two application :

One drive for Swing motor

One drive for two travel motors (less use) 

Jeff Casagrande

First, for line reactors.  Line reactors should be used if the TOTAL cable length exceeds 50m for shielded cable and 100m for unshielded.  The reactor, if used,  should always be attached to the output of the drive before any other component.

In the case where you have two motors connected in parallel, the drive overcurrent protection (it sees the current of both motors) can no longer protect the individual motors.  In this case, separate overload relays should be used.

In all cases, your output contactors should never open under load.  You will damage the drive if this happens.

Read this FAQ first https://support.industry.siemens.com/cs/document/1017401/micromaster-sinamics-g110-g120-(cu2x0x)-g120c-v20%3A-using-a-contactor-mccb-isolating-switch-on-the-inverter-output-?dti=0&lc=en-WWld

It is generally not recommended not to do this.  I would use separate drives, but its your budget.  Realize that the long engineering, test and commissioning time will more than likely cost more than another drive.

You can do some intricate interlocking with contactor and overload selection which will open the Pulse Enable.

 Dear Jeff

In the case multi motors use one drive, it need overload protect for each motor. When under load, overload protect active, it mean motor will disconnect to the drive(like contact open suddenly under load ). In this case what happen ? 

Do you know the model of the overload protection can connect between drive and motor ? I read on a topic that he use MCp but it suddenly trip when drive running. Do not know why

Jeff Casagrande

Read this FAQ first https://support.industry.siemens.com/cs/document/1017401/micromaster-sinamics-g110-g120-(cu2x0x)-g120c-v20%3A-using-a-contactor-mccb-isolating-switch-on-the-inverter-output-?dti=0&lc=en-WWld

It is generally not recommended not to do this.  I would use separate drives, but its your budget.  Realize that the long engineering, test and commissioning time will more than likely cost more than another drive.

You can do some intricate interlocking with contactor and overload selection which will open the Pulse Enable.