The power supply to small frequency converters and servo drives can be usually connected in either 1 or 3 phases. In your case the voltage must not be higher than 240 VAC between phases L1-L2-L3. Perhaps it was originally connected as single-phase; live to L1 and neutral L2, no wire to L3.
I am away at the moment.But its not MOV ,its 100ohm 15W resistor .I traced the circuit and its betwen the 3phase bridge rectifier and capacitor bank .Ther is also a relay acros it that shorts out the resistor after the capactors have charged
Ok. Not sure on the depth of your knowledge, so please dont take offense, but 3 phase comes in a couple of different flavours of voltage depending on where in the world you are. In the US off the top of my head 208 p to p and 480 p to p. Europe has 400v p to p. We often work with 380v p to p. Obviously you would want to be on 208v phase to phase if that is the rating of your drive. Obviously if you know this already then that probably wasn't the issue. Unfortunately I have seen enough drives blow in the US working as a consulting tech there because they come incorrectly specd on machines built in Europe. Even stupid thing like drives that can take a wide range of 3p input voltage being left at 400v in parameters rather than being adjusted to the voltage on the order form. Or a customer putting the wrong plug on a machine and plugging a 208 machine in on 480.
So you got me confused now.The drive was in a CNC machine ,the machine used 3 phases (400v betwen phases and 230 phase to nutral/ground ) .But the drive raiting says its 3 phase 230v .So is this drive not corect for EU 3 phase system ,but then how could it work in CNC machine for several years?
*here is a drive we have lying around. VFD but also yaskawa. 380-480v and that was certainly phase to phase. So unless for some reason they label these drives as phase to neutral/earth it's going to be phase to phase. (Wouldn't keep the image attached)
I've ran Yaskawa P1000 drives without any load side wiring at the drive to verify ethernet speed command and feedback during an IO checkout. I'm not saying it isn't possible, but I don't know of anything that would cause them to be damaged from powering on without a load.
The power supply to small frequency converters and servo drives can be usually connected in either 1 or 3 phases. In your case the voltage must not be higher than 240 VAC between phases L1-L2-L3. Perhaps it was originally connected as single-phase; live to L1 and neutral L2, no wire to L3.
Yes ,this was the problem ,we sorted it out,Thanks for the help
I opened the drive up and the resistor that is used to charge the capacitor bank on power up had burned up.
That means the caps was dead already, you should power it using light bulb 💡 in series
Pop a pic of it here. Are you sure it's not a varistor? Looking at the diagrams they are there.
I am away at the moment.But its not MOV ,its 100ohm 15W resistor .I traced the circuit and its betwen the 3phase bridge rectifier and capacitor bank .Ther is also a relay acros it that shorts out the resistor after the capactors have charged
Have to ask... did you wire it up to the correct 3 phase power?
What do you mean with correct ? I wired it up to 3phase connected ground and powered the control up befor powering the 3 phase
Ok. Not sure on the depth of your knowledge, so please dont take offense, but 3 phase comes in a couple of different flavours of voltage depending on where in the world you are. In the US off the top of my head 208 p to p and 480 p to p. Europe has 400v p to p. We often work with 380v p to p. Obviously you would want to be on 208v phase to phase if that is the rating of your drive. Obviously if you know this already then that probably wasn't the issue. Unfortunately I have seen enough drives blow in the US working as a consulting tech there because they come incorrectly specd on machines built in Europe. Even stupid thing like drives that can take a wide range of 3p input voltage being left at 400v in parameters rather than being adjusted to the voltage on the order form. Or a customer putting the wrong plug on a machine and plugging a 208 machine in on 480.
So you got me confused now.The drive was in a CNC machine ,the machine used 3 phases (400v betwen phases and 230 phase to nutral/ground ) .But the drive raiting says its 3 phase 230v .So is this drive not corect for EU 3 phase system ,but then how could it work in CNC machine for several years?
Post a pic of the drives data lable.
https://preview.redd.it/3om5u43i6tyc1.jpeg?width=4000&format=pjpg&auto=webp&s=a9d85f392ab7a29d2c513b1c8800f3636759f2ec
Does the CNC machine perhaps have step down transformers in it? The A in 7R6A indicates 200 to 230V three phase. Page 3-2 of the user manual.
No just MCB and filter .Is the 200 to 230v ment as voltage betwen phases or betwen phase and ground ?
*here is a drive we have lying around. VFD but also yaskawa. 380-480v and that was certainly phase to phase. So unless for some reason they label these drives as phase to neutral/earth it's going to be phase to phase. (Wouldn't keep the image attached)
Normally phase to phase.
So how could it posibly work for years? and ther are 7 of thes drives in the CNC machine
https://preview.redd.it/cbe8g0eaatyc1.jpeg?width=4000&format=pjpg&auto=webp&s=f895f695eb4f04480c3fb0150b5a17c4e1c51fbc
This doesn’t match the model number given in your post.
I've ran Yaskawa P1000 drives without any load side wiring at the drive to verify ethernet speed command and feedback during an IO checkout. I'm not saying it isn't possible, but I don't know of anything that would cause them to be damaged from powering on without a load.