text: <s>[INST] Using motor terminator for cable length more than 189 A Rockwell 1204-TFB2 motor terminator with the serial number: MEAB30Z6 has been bought in order to reduce PWM peak voltages at the motor terminal. The VFD and the motor specifications are as the following: VFD Power: 580 kW Motor Power:580 kW Voltage (rms at VFD output and Motor terminal): 580 V DC Link Voltage: 900 V Cable length: 250 meter Filter: a Series Reactor at VFD Output PWM Peak Voltage at Motor Terminal: 1700 V (Twice the DC Link) PWM Rise Time at Motor Terminal: 0.2 us PWM Rise Time at Motor Terminal: 3-4 us According to the 1204-TFB2 datasheet, the maximum cable length should be less than 182.9 meters. Unfortunately, the length of the cable in our study case is about 250 meters. A series reactor has been installed at the VFD output, which increases PWM rise time and reduces the reflection phenomenon at the motor terminals. In other words, using a series reactor reduces the peak voltage at the motor terminal in comparison to when this reactor has not been installed at the VFD output. However, is it possible to use 1204-TFB2 in this case study (in this case study, cable length is more than 182.9 meter)? In other words, the limitation of the cable length can be increased by using a series reactor at the VFD output? [/INST] Hamed, The maximum length of 182.9m (600 ft) is correct as stated on page 94 of https://literature.rockwellautomation.com/idc/groups/literature/documents/in/drives-in001_-en-p.pdf Which drive are you working with? For our drives we have tables that provide the options for mitigating reflective wave issues. For example our 800 Hp PowerFlex 755 table 56 is on page 139 of the same manual I provided above. For cables over 250m you would need a reactor and a damping resistor and also a motor insulation rating of 1850V or more. You should not use a reactor with a motor terminator because it can cause voltage spikes exceeding the motor insulation ratings. This is documented in our Knowledgebase QA27120: https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/686116 Unfortunately, you cannot safely use a motor terminator at that cable length. \\n </s>