Vfd control panel

[russ57]

It's high time I sort out my vfd by adding a remote control panel.
It's for a 6x26 mill. I'm looking for comments /suggestions as to what controls are useful, eg, reverse? Jog?. Run stop plus speed are obvious.
And photos of actual panel layout would be great...
Have you hard-wired it, or some type of connector?

All thoughts welcome...



-russ

[jhovel]

Hi Russ,
have a look at this thread: http://metalworkforums.com/f65/t183843-external-panel-option-huanyang-vfd
They are my lathe and mill panels - and lots of discussion and discovery of VFD control parameters.
I think I have the Huanyang ones down pat now :)
As you can see, I like to have forward, reverse, for and rev jog, normal stop, emergency stop and table feeds, as well as a spindle rpm readout - all in the same panel. It works for me.

[russ57]

Thanks! A good read and something to consider.
I had about decided jog wasn't necessary.

-russ

[jhovel]

You are absolutely righ: jog isn't necessary.
However, I suspect it has saved me a couple of cutters so far: I'm clumsy at times and have been known to position a cutter too close to the work (like a corner of the workpiece between teeth or a misjuged reach of my flucutter). At my jog frequency of 5Hz, my motors produce very little torque - and the resulting "clunk" and a stopped spindle is all I got.... if you get my meaning.

[HattyDamp]

Hi...i am a new user here. I design electrical systems for industrial installations and I'm not clear on how to size a feeder for a control panel containing multiple VFD's. If I consider that control panel to be an Adjustable-Speed Drive System, 430.122 says Branch/Feeder conductors must be sized 125% of the input current of the power conversion equipment. Does that mean I need to add up the total VFD input current and add 25% for the feeder size?
If I consider the control panel to be an Industrial Control Panel, 409.20 says the supply conductor must be sized for 125% of the full-load current of the largest motor plus the sum of the full-load current of all other motors. There's no mention here of VFD's or sizing the conductor based on VFD input current rather than motor full-load current.This gets to be an issue where a panel shop puts several over-sized drives in a panel. I recently had a project where there were 15 VFD's in a panel serving 1HP - 5HP motors, and the shop put in all 7.5HP drives.

[russ57]

It appears you are quoting USA codes? Presumably you are in the USA. Id suggest you consult a local qualified engineer, perhaps also your inspector, as it seems to me the definition of the type of panel is the critical issue here, and that may partially at least a matter of local practice.

-russ

[eskimo]

Hi...i am a new user here. I design electrical systems for industrial installations and I'm not clear on how to size a feeder for a control panel containing multiple VFD's. If I consider that control panel to be an Adjustable-Speed Drive System, 430.122 says Branch/Feeder conductors must be sized 125% of the input current of the power conversion equipment. Does that mean I need to add up the total VFD input current and add 25% for the feeder size?
If I consider the control panel to be an Industrial Control Panel, 409.20 says the supply conductor must be sized for 125% of the full-load current of the largest motor plus the sum of the full-load current of all other motors. There's no mention here of VFD's or sizing the conductor based on VFD input current rather than motor full-load current.This gets to be an issue where a panel shop puts several over-sized drives in a panel. I recently had a project where there were 15 VFD's in a panel serving 1HP - 5HP motors, and the shop put in all 7.5HP drives.


i cant help wonder as to how and why you can design such electrical systems and yet ask for said info on a public forum which WILL contain non qualified advice.

[BaronJ]

Hi...i am a new user here. I design electrical systems for industrial installations and I'm not clear on how to size a feeder for a control panel containing multiple VFD's. If I consider that control panel to be an Adjustable-Speed Drive System, 430.122 says Branch/Feeder conductors must be sized 125% of the input current of the power conversion equipment. Does that mean I need to add up the total VFD input current and add 25% for the feeder size?
If I consider the control panel to be an Industrial Control Panel, 409.20 says the supply conductor must be sized for 125% of the full-load current of the largest motor plus the sum of the full-load current of all other motors. There's no mention here of VFD's or sizing the conductor based on VFD input current rather than motor full-load current.This gets to be an issue where a panel shop puts several over-sized drives in a panel. I recently had a project where there were 15 VFD's in a panel serving 1HP - 5HP motors, and the shop put in all 7.5HP drives.

Both are correct ! In essence what it is saying is that the feeder has to be sized according to the biggest load, that is the sum of all the loads plus 25%. The fact that you have an installation that has oversized VFD's driving undersized loads is not the issue. The total load is.

As far as VFD's are concerned it is probably cheaper to buy all 7.5HP units than to buy different sized ones to suit each load. In terms of inventory it would be less costly managing only one size than having to manage a dozen.