ground pads on the machinery skids? proper installation?

[emiller233]

we're building a big hydraulic pump skid. The customer wants grounding pads put on the metal skid for each motor to attach to. not sure how to do this properly?

doing some quick googling, I'm seeing alot of steel pads that just got bolted to the metal skid. Is this acceptable?

will use a braided strap between the motor and the skid

 

[ActionDave]

There is not anything made of copper that is going to bond the parts of a metal skid any better than the welds and bolts that are going to hold it together.

Your gonna have an iron motor bolted to an iron platform with iron nuts and bolts. The copper strap in your picture might as well be a Christmas ornament.

 

[emiller233]

we've told them this, but they don't care... :slaphead:
these motors are mounted onto isolation bars (rubber?) which are then mounted onto the skid.

 

[ActionDave]

Even with the rubber pads the motor will have an equipment ground.

As long as.everything is wired properly, which I'm sure it will be, any additional bonding is supplemental and you can do what you want.

 

[kwired]

Depends on what you all have on the skid.

NEC wise the electric components - motor, controller enclosure, etc. are all that need an EGC and will already be bonded together via said EGC. Other metal frames are often solidly bolted somehow to at least some of those items and are bonded anyway. If something is isolated and static concerns arise then maybe additional bonding jumpers are a way to address it. Otherwise NEC is mostly only concerned with bonding what could potentially be energized by power/control circuit conductors to the EGC.