Selecting a DC Drive for a Lenze 1.5 kW Motor: 6RA70 vs 6RA80

David Krause2 min read
Application NoteSiemensVFD / Drives
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Motor Nameplate Data and Application Context

The motor to be controlled is a Lenze DC motor, type FGN 432P, rated 1.5 kW with IP54 protection at 2800 min-1. The nameplate lists an armature rating of 160 V / 10.9 A and a field rating of 200 V / 0.24 A (works number 36981). The motor drives a gearbox (reductor) on a textile winding machine, so the drive must deliver stable speed/torque control under a geared load typical of winding duty.

Parameter Value
Motor type Lenze FGN 432P
Rated power 1.5 kW
Rated speed 2800 min-1
Armature 160 V / 10.9 A
Field (excitation) 200 V / 0.24 A
Protection class IP54
Application Textile winding machine with gear reducer

Verifying the SIMOREG 6RA7013-2FV62-0

The SIMOREG DC Master 6RA7013-2FV62-0 is a valid choice for this motor. The critical check is the supply voltage: the 'F' position in the order number designates a 440 V supply rating. Because the motor armature is rated only 160 V, the output must be limited by setting the rated supply voltage parameter P078 accordingly during commissioning, so the converter does not push the armature above its nameplate voltage.

Alternative: SINAMICS DCM (6RA80)

The second choice is 6RA8013-xxV62-0 from the SINAMICS DCM family, which is the designated replacement for the discontinued SIMOREG 6RA70 series. For a new installation, the 6RA80 offers current product support and the same basic DC converter functionality; the 'V62' suffix denotes the same converter class, with the remaining order-number positions selected to match the required supply voltage and options.

Supply Voltage and Protection Considerations

Select the line supply voltage carefully: applying overvoltage to the DC drive can damage the power module. Because the available supply may be significantly higher than the motor's 160 V armature rating, the safer engineering practice is to install a step-down transformer of adequate rating ahead of the drive. This protects the motor against overvoltage injection in the event of a drive trip or a runaway condition, and it also matches the converter input to the installation rather than relying solely on parameter limitation.

Frequently Asked Questions

Can I use a 6RA7013-2FV62-0 on a 160 V Lenze DC motor?

Yes. The 'F' in the order number means the unit is built for a 440 V supply, but you reduce the effective output by entering the correct rated supply voltage in parameter P078 during commissioning so the 160 V / 10.9 A armature is not overstressed.

What is the modern replacement for the SIMOREG 6RA70?

The SINAMICS DCM series is the official successor; for this application the equivalent is 6RA8013-xxV62-0, with the order-number positions chosen to match the required supply voltage and options.

Do I need a transformer between the supply and the DC drive?

A step-down transformer of adequate rating is recommended when the line supply exceeds the motor's 160 V armature rating, because overvoltage can damage the drive's power module and can reach the motor during a drive trip or runaway event.

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