Voltage spec for 3-phase VFD drive and motor - Page 1
Forum section: electronics / beginners

author: Alex
author_rank: Regular Contributor
timestamp: November 18, 2019, 01:31:30 pm
content: Perhaps a very basic question;I am confused by the following specification of three-phase voltage levels.I am to specify VFD drives for a motor application.The motor is specified as 400/690 V three phase.The VFD drive I am considering is from the Schneider Electric Altivar processATV600 line, which can be specified for a voltage rating of 200...240 V, 380...480 V, 380...440 V or 500...690 V.The plug available at the facility is a CEE type, red in colour.I am unsure what is the correct spec for the VFD drive and whether the components are compatible with the available supply?Alex

author: GerryR
author_rank: Frequent Contributor
timestamp: November 18, 2019, 02:09:58 pm
content: Two things to consider:1) Voltage AND HP of the motor2) Available Power to the drive, whether 1 ph, 3 ph and the voltage available.Drives come with the option of 1 ph or 3 ph inputs (the drive does the conversion to 3 ph for the output). The drives that work from a 1 ph input need to be derated for the motor output because of the way the 3 ph is internally generated for the motor. Most drives are set to be hard-wired to a panel with appropriate breakers / fuses and disconnect switch. You can make them pluggable, but you still need to provide the fuses on the input and a disconnect switch.What are the specs of the motor you are driving? Read the nameplate data on the motor and we can better help with specing the drive.

author: Alex
author_rank: Regular Contributor
timestamp: November 18, 2019, 02:20:10 pm
content: Motor spec is 400delta/690Y, power is 4kW (5.5 HP).Potential drive isthis one, which has a nominal power rating of 4kW. This is rated for a voltage of 380-480VAC three phase. However there is a version rated for 200-240 VAC three phase, otherwise identical.I am not certain as to what voltage is available, however the socket is red, which I understand indicates 300–480 VAC split phase power. See attached picture of socket. I could measure L-L and L-N if needed.Does this help?

author: GerryR
author_rank: Frequent Contributor
timestamp: November 18, 2019, 04:32:29 pm
content: It looks like the drives are specified for the same input and outputvoltages. The drives are also specified for Y connection. I would contact Schneider to see if 480 delta is ok. Also I would go to the next size drive (ATV630U55N4, 5.5 kW, 7.5 HP, if you expect the motor to be heavily loaded. From all that I have read, the 480 unit is what you need for the 480 motor ( the 240 V drives would be for 240 V motors). You need to be sure what your supply voltage is, so I would measure it.Here is a selection chart I found on their website.https://download.schneider-electric.com/files?p_enDocType=User+guide&p_File_Name=ATV600_Getting_started_Annex_EAV64300_11.pdf&p_Doc_Ref=EAV64300Hope this helps.

author: cs.dk
author_rank: Unknown
timestamp: November 19, 2019, 07:03:32 am
content: Quote from: Alex on November 18, 2019, 02:20:10 pmBetween L-L you would have 400VAC, and 240 VAC between any hot and neutral. 3x240VAC is not common in europe afaik. It's only in Norway that thing exists.

author: Al3579
author_rank: Newbie
timestamp: November 19, 2019, 10:24:46 am
content: Your Motor can be wired for 3 phase delta ore 3 phase wye. There is usually a plate over the motor that you can rearrange the windings with a screwdriver.Now incoming 3 phase power can be 3phase wye or delta. 3 phase delta has 3 legs with each having same potential across them and so does 3phase wye.Wye has a fourth wire the difference between the center tap & phase vs phase & phase is thethe square root of 3.Now with the vfd you got to actually measure mains supply to find a vfd that is compatible.

author: Alex
author_rank: Regular Contributor
timestamp: November 19, 2019, 05:43:02 pm
content: All is in order now.Facility supply available at outlet is 3P + N + PE, 415 VAC measured line-line.I went with the 380-480 VAC VFD, specified as line-line voltage. I went for 5.5kW as suggested.The VFD manufacturer confirmed operation with said motor, which is 400V delta or 690V Y.Thanks for the help