vfd cable

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RETRAINDAILY

Senior Member
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PHX, arizona
A job I am on has a control panel with vfd cable from the drives to terminals that we are to hook are wires too.

they are 4-20 controlled (shielded) and allot of them.

1 HP motors on over sized drives- 3 HP

IMO it would be better to take are wires right to the inverter.

any input :confused::-?
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
A job I am on has a control panel with vfd cable from the drives to terminals that we are to hook are wires too.

they are 4-20 controlled (shielded) and allot of them.

1 HP motors on over sized drives- 3 HP

IMO it would be better to take are wires right to the inverter.

any input :confused::-?
Having all the control signal wires terminate in the same area might make testing and troubleshooting easier. I don't see any problem with it.
 

eric7379

Member
Location
IL
A job I am on has a control panel with vfd cable from the drives to terminals that we are to hook are wires too.

they are 4-20 controlled (shielded) and allot of them.

1 HP motors on over sized drives- 3 HP

IMO it would be better to take are wires right to the inverter.

any input :confused::-?

As Jraef already mentioned, there should not be any problem with it. I wish more manufacturers would do it this way. It makes troubleshooting a heck of a lot easier instead of everything being wired point-to-point. It comes down to manufacturers trying to make their product as cheap as they can, so if they can eliminate a few bucks or so (or possibly a few hundred or even thousand) by doing away with terminal strips, they will do it.
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
You didn't say anything about motor leads before.

BIG issue on the motor leads: noise.
VFD output cables are like very powerful local radio broadcast antennae. By routing the leads to terminal blocks inside the panel in the way the panel builder knows is safe, he has reduced the possibility that the installer will route them in a way that causes cross talk and interference with the other devices / controllers / communications components etc. This is especially important in a panel with multiple VFDs and/or other RFI/EMI sensitive equipment in it.

Trust me, it is WAY more expensive for the panel builder to do it this way, if he were cheap he would have left it to you to run the cables into the VFDs and then if anything went wrong, blamed you for it. So by providing a terminal block for the field wiring the panel builder has essentially absolved you, the installing electrician, of that responsibility. You should be grateful.
 
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RETRAINDAILY

Senior Member
Location
PHX, arizona
You didn't say anything about motor leads before.

BIG issue on the motor leads: noise.
VFD output cables are like very powerful local radio broadcast antennae. By routing the leads to terminal blocks inside the panel in the way the panel builder knows is safe, he has reduced the possibility that the installer will route them in a way that causes cross talk and interference with the other devices / controllers / communications components etc. This is especially important in a panel with multiple VFDs and/or other RFI/EMI sensitive equipment in it.

Trust me, it is WAY more expensive for the panel builder to do it this way, if he were cheap he would have left it to you to run the cables into the VFDs and then if anything went wrong, blamed you for it. So by providing a terminal block for the field wiring the panel builder has essentially absolved you, the installing electrician, of that responsibility. You should be grateful.

Will the 1 hp motors really cause that much damage to the analog signal ?

The issue is they want me to install reactors on all the drives and we are running out of room fast.

If I could do away with that set up and hook right to the drive
(That would free up enough space for about 15 reactors within 5' of the furthest drive.)

and

install the two compartment wire way (that would require a total remodel of the panel.)

maybe

Zip tie the analog to the bottom of the wire way.

or...?
 
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