VFD Cables

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mull982

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I have been reading some information lately above VFD cable. I am trying to figure out weather or not I should use this cable on two new drives I'm installing. The drives are small Siemens MM440 drives used for 5hp motors.

I gues my question is, should VFD cable be used in all applications or are there some where it should be used in others where it should be not. What is the rule of thumb for applying this cable and what are the benefits that justify its use?
 
If you beleive what you are reading, then you should use the cable. If you use it on one installation, then why not us it on all installations?

The biggest gripe I've heard is that it is expensive. It may also be difficult to get in shorter/cut lengths, so for a couple of short runs you may have to buy a larger quantity, and that may be hard to justify, especially if you don't see much near term additional installs to use it up.
 
IMHO, VFD cable is a waste of resources where load conductors are run in grounded metallic raceways, especially for low horsepower pump/fan applications.
 
As I mentioned this would be used for two 5hp travel drive motors.

Is the only reason this cable is used, for corona and to protect electric field dissipation from one conductor to the other
 
VFD cable is used to help mitigate the negative effects associated with VFDs. The effects are very real, and cable manufacturers have tried to come up with ways to help mitigate those effects. i'm sure some products work better in some situations and vice versa. Two of the problems encountered you mention, there are others.

IMO - I would use the VFD cable, especially on 6-pulse drives. Keep in mind, 6-pulse drives do not meet IEEE 519 without adding additional equipment.
 
Assuming travel drives means the conductors need to flex, then by all means use the VFD cable. I would take a chance on std triplexed cables run in rigid conduit, but for flex applications, SO or any other portable cord is strictly out of the question.

Think of what a PWM drive does: Pulse Width Modulation of voltage to attan amplitude and frequency modulation.. Sound anything like "Amplitude and/or Frequency Modulation", as in a powerful AM/FM radio antenna? You bet it does!
 
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