If using a small mains pump, as i do, use a separate relay to control it from the vfd.

The vfd has a relay - you need to set the parameter which turns this on when the vfd is in the 'run' condition.

Next, feed this relay a 24v supply to the 'com' or common contact, then from the 'n/o' or normally open contact you go to the +(if marked) terminal on your pump relay, the - terminal then goes back to your 24v supply.

Now you have a separate relay which turns on with the vfd. The relay will have common and normally open contacts - feed a fused live supply (1A or 2A fuse) into the common, then normally open to your pump, other pump lead back to neutral.

That should be it :)

The reason i would do this is for isolation - i don't like having 240v mains anywhere near the logic side of the vfd terminals.