Suggested cables that carry both motor phases and encoder signals?

1

Hi,
we’re trying to make a bunch of motors, connected to ODrives, slightly easier to wire up. We’ve found a few suggestions for cables, which seem to be with three-phase wiring in mind: there are three heavy-gauge conductors (capable of 30A), and a bunch (e.g. 7-9) signal conductors for up to 1A. These seem to be perfect for driving PMAC motors, since we need 3 + 5 + 2 conductors (3 phases, 5V/GND/A/B/Z signals, and brakes). However, the ones we’ve found so far only have metal shielding around the signal wires. From what we’ve heard, speciality cables for VFD use are shielded around the heavy-gauge wires, to avoid the EMI, and allow for the assembled machine to pass EMC testing.
We’ve specifically asked Amphenol on one of their products with this configuration (WCA00010635), and they’ve confirmed it is not designed for VFD use.

Any suggestions for cables that have separate shielding for the power conductors vs signal conductors? Or at least have shielding around the power conductors?

Our specs are:

  • power conductors: 3 x 21A or more (AWG10 or 12)
  • signal conductors: at least 7 x 0.3A (no thinner than AWG32)
  • cost: as long as it is <$3.50/ft, that’s fine
2

Hmm, great question.

Quick search on my end didn’t bring too much up.

Unfortunately I think maybe just getting some normal (shielded) VFD cable, shielded signal cable, and a few spools of appropriately sized cable conduit may be the right move.

All that being said, I typically think of VFD driven machines as having pretty significant dv/dt given the lines voltages involved, and usually their slightly more primitive drive methods :slight_smile:

We’ve definitely had a customer using ODrive Pro pass EMC testing, but I’m not sure if they were using shielded cables or not. The v3.6 will definitely be worse on the EMI front though. I’d maybe recommend first just trying some ferrite rings and doing a pre-qualification scan in your lab?