Can I mount my vfd inside the mill column or would it overheat?

[Rata222]

The Delta vfd I am getting, has a removable control panel. I'm not sure how much heat a vfd gives off. Would it be okay to mount the vfd inside the mill column itself. As seen in the picture, the back panel comes off. I could mount it to the back of that.- inside the the column. I could locate the removable control panel, containing the switches and display, on the side of the mill where the current on/off buttons are. I will also add controls at the front of the Mill. There are vent holes at the bottom of the mill base but none at the top where heat could escape. Do you think the vfd would remain cool enough?

Thanks, Jim

 

[coolidge]

Meh, that's a large cast iron heat sink but electronics don't like vibrations I'd probably mount it on some rubber isolation pads.

 

[Alexander McGilton]

The manual to the VFD will often list a minimum CFM of air passing through the enclosure. Or that is at leat the case for the larger units. I would suggest putting a 120v 4inch fan on the access cover. The fan will take well less than a 1Amp to run. Wire it to the logic circuit of the VFD. Or one lead of the motor to neutral if at 208v 3ph.

 

[mksj]

Dissipation at idle is around 60W, they are about 97% efficient so even at full power they do not dissipate that much heat and that is both a large volume space and a lot of metal for heat dissipation. I often place them in a sealed metal enclosure at least 7-8X the volume of the VFD. I do not see the need to add a fan, as the VFD has one which will dissipate the heat up. If you want some convection air flow put some louvers or a screen over the upper access and mount the VFD against the column below the lower access or either side internally. You will have limited access to the VFD display and the ability to do any programming once mounted. I see no problem with mounting it in the column. Also make sure that no swarf or liquid can get into the column.

 

[Rata222]

Thank you guys for taking the time to respond- in detail. It was my feelings that there was enough metal to act as a heat sink, and there was quite a lot of volume inside the column. But I don't have any experience with VFDs. I wasn't sure if a fan would help since it is enclosed with only the vent at the very base of the mill. I can certainly add one if it would help and perhaps that the upper part of the access panel. I think vibration isolators are a great idea and will add those.
MKSJ. This Delta unit is made so the digital keypad and display are wired so you can pull them off the unit and locate them a few feet away from the main box. So it lends itself to to not needing access to the main unit.

Thank you again guys for your input.
Jim

 

[markba633csi]

I believe some units can be programmed to beep if they get too hot- I think they can even go into standby mode
I'd probably put a small fan anyhow just to circulate the air- can't hurt

 

[Eddyde]

I would put some sort of venting at the top of the column, like a couple of holes, just to be sure. I have a 7.5 hp rated VFD running a 5 hp motor (air compressor) that overheats if running continuously in warmer weather, and it's mounted out in the open, no enclosure.

 

[MikeInOr]

Is the mill going to be running in a production environment? A good solid 8 or 16 hours a day of hard work? If so add a fan.

If it is a home shop I think you will be fine just mounting the VFD to the inside of the column like you are planning. The power transistors (Mosfet's/IGBT's) are quite efficient and won't give out enough heat to appreciably heat up the cast iron of the column no less heat up enough to shut down. All VFD's I have worked with have thermal overloads built in which will shut them down before they can do any harm to themselves. The cast iron base is going to be a MASSIVE heat sink. You will have to run the mill 24 hours a day to heat up all that cast iron.

Personally I would do what you are purposing. If it shuts down, I HIGHLY doubt it will, add a fan when that happens.

 

[tq60]

Heat rises so it will do fine until the heat fills the column.

A fan is okay, but it needs help.

Get a 4 inch fan and some dryer vent hose.

Also some sheet metal.

The fan needs to blow out, if there is not a cover that can be drilled or replaced, make a box that the fan points in near the bottom of the column and shape it to direct the air towards the floor and outside of the unit.

Make an adaptor for other side of fan to attach hose.

Route hose to highest place in the column.

Heat rises, the fan draws air from top and blows it out at the floor.

Replacement air enters at floor level, coolest air in shop.

Sent from my SM-G781V using Tapatalk

 

[coolidge]

Something else to consider, the last VFD I owned was quite noisy. A higher pitch annoying squeal I hated listening to that. This was some years ago so maybe they have improved.