Line-side Conductor Heating on A-phase, 250 HP, PowerFlex VFD

[CR1SHNA]

Having an issue with line-side cable for only phase 1 being 30^oF hotter than phases 2 and 3. See the photo below. Any suggestions?

https://imgur.com/a/HJHI2a3

 

[retirede]

Are the cables terminated in that ‘box’?
If so, you have a bad connection. The hottest point is toward the termination.

 

[petersonra]

Are the cables terminated in that ‘box’?
If so, you have a bad connection. The hottest point is toward the termination.

That looks like it is the bottom of the VFD. 30° isn't all that much difference. There may be just be less air circulation on that side. Unless there's reason to believe that there is a problem I would not get excited about such a minor temperature difference.

 

[retirede]

That looks like it is the bottom of the VFD. 30° isn't all that much difference. There may be just be less air circulation on that side. Unless there's reason to believe that there is a problem I would not get excited about such a minor temperature difference.

I’d still re-torque the terminations. If that’s what’s causing the heat, it will only contribute to corrosion and get worse.

 

[ptonsparky]

I’d still re-torque the terminations. If that’s what’s causing the heat, it will only contribute to corrosion and get worse.

Ditto.

 

[tom baker]

Get some burndy pentrox e which is for copper only. Remove, clean, apply penatrox e, tighten with torque wrench.

 

[CR1SHNA]

I’d still re-torque the terminations. If that’s what’s causing the heat, it will only contribute to corrosion and get worse.

Thank you everyone for your feedback. We did have heating issues in this enclosure as it had inadequate air flow. We also replaced the cables and re-torqued to spec.

 

[Jraef]

... it had inadequate air flow.

The bane of VFD applications. People mount and wire them as if they are motor starters. They are not.