VFD CABLES
- Thread starter hawkeye23
- Start date
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I would.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Just curious, not arguing - why?
What benefits/advantages? Just trying to learn here.
Aleman
Senior Member
- Location
- Southern Ca, USA
As far as I know VFD cable is just cable that includes 2 wires and shielding for a low voltage switch to work with the disconnect.
We use them to provide input to the control to shut down the VFD before power is off. The aux switches break before the mains break.
Otherwise any appropriately rated SO type cable would be ok, unless you need a switch or the shielding.
We use them to provide input to the control to shut down the VFD before power is off. The aux switches break before the mains break.
Otherwise any appropriately rated SO type cable would be ok, unless you need a switch or the shielding.
For us in UK, it is almost never a contentious issue. We use steel wire armoured cable (SWA) for all power. It's symmetrical and has effectively a continuous metal sheath. Even where it goes via a disconnect between the drive and the motor, that disconnect is in a metal enclosure ensuring continuity of the screening. A Faraday cage.
It's standard practice.
An excerpt from the Gambica technical publication on Installation Guidelines.
"It is strongly recommended that the cable be screened. This is essential in order to meet meet many of the relevant EMC standards, and in any case to reduce the risk to other equipment."
"To meet EMC requirements only shielded multicore cables should be used."
The EMC directive, the potted version:
In essence, no piece of equipment may emit undue electromagnetic emissions or be unduly susceptible to external emissions.
It's a practical guide and it seems to work.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Cool, thanks Bes.:thumbsup:
You are welcome, Del Boy*.
As an old colleague of mine used to say:
"I don't understand everything I know." That may be a wee bit more subtle than at first glance.
*I may come back to that.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
weressl
Esteemed Member
ASD rated cables utilize a higher insulation rating up to 2kV, use triple grounding wires evenly space between the phase conductors to equalize phase-to-ground voltage stresses and utilize some sort of RF/EM screening.
sparkyrick
Senior Member
- Location
- Appleton, Wi
I thought any drive load conductors needed shielding, or be in their own raceway?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Only if you are concerned with causing problems at the other equipment whose wiring shares the raceway.
weressl
Esteemed Member
Naah, problems go much further than just adjacent cables.
Aleman
Senior Member
- Location
- Southern Ca, USA
We have had a few strange events and equipment damage in our new facility. This is a cellar, bright beer for packaging. Lots of pumps, temp control, CIP systems.
Not all of our pumps are wired with VFD cable because we ran out of it. We had some 12-4 SOOW and used that. We lost a comm base for AB drives, 2 power modules
on some Numatics remote I/O valve racks. Fuses blew ok, but damage was done. All lost equipment ran on 24VDC. The voltage had to have spiked. So now I wonder
if we have a bad power supply, SOLA made, or we are getting voltage spikes into our comm lines or power supply lines. All cabling is in tray, and AC is separated from
the low voltage in the tray by a divider. So, what kind of problems
can non shielded VFD driven motors cause?
puckman
Senior Member
- Location
- ridgewood, n.j.
I thought vfd needed swa cable because of thepulse or spiking in the cable would penitrate thnn type wie and cause a fault This is something i picked up along the way but i can't be sure.
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