Toshiba G9 input voltage status contact

I will be using a Toshiba G9 VFD on a new installation with its input power wired from a lockable disconnect. The disconnect switch is going to be locked out during maintenance, and I would like to get an indication from the VFD when 480v power is turned on to the drive so I do not have to monitor the power by another means. I want to have the drive switch 120v control power back to the PLC when 480 power is present.

I see a few options I could use (possibly the fault contact, or program OUT2 to the Mains Circuit Under-Voltage Alarm) , but the manual does not get into a lot of detail about when the relay would change state in either of those configurations.

Has anyone had experience with this before?

I have a machine at work with a G7 series wired this way...the standard nomenclature would be Relay Output configured as Ready or Fault (open when fault) to get a ready status...not exactly what you asked for, but inclusive of it.

When the drive is powered up, has done its tests and is happy, the relay will close, losing one phase may not drop it out until a fault occurs due to low voltage.

If you open the disconnect with the drive idle, it can take several seconds for the drive to fault, so your signal will be delayed.

It's good to have an early break contact on the disconnect in series with the drive enable, so it "let's go" of he motor before the disconnects open, reducing arcing and motor/circuit damage.

You can find the installation & operation manual at the following page.

http://www.ctiautomation.net/Toshiba-G9-Drives.htm

Why so complicated? Why not just put an aux contact on the disconnect switch to feed the PLC when it is in the Closed position?

Using the output of the VFD for a circuit to power remote devices is putting the expensive VFD at risk to common mode noise coming in on that circuit, and/or a short in those wires taking out the PC board. If you insist on doing it this way for some reason, use an interposing relay.