I am having a problem with the way electrical contractors are installing motors here at our new plant that is being built. For each motor they are doing two things.
1) Running a #12 or #10 ground wire from the motor frame to somewhere on the steel structure. The contractor is claiming that this is required by code and is the correct way of doing this. He is using this size wire regardless of motor size.
2) Where flexible conduit is used at the motor terminal box he is running #12 ground wire and wrapping it around, or tie-wrapping it to the flex conduit and them attaching it to the rigid conduit or somewhere on the steel structure. He claims that this is required by code to be used as a bonding jumper across the flex conduit. I argue that the flex conduit already has a bonding jumper inside but he claims this is not large enough.
Can anyone help me out in determining if either of these two practices are correct or required by code? I should mention that with each motor feed inside the conduit there is an EGC sized according per code running from the MCC ground to the motor frame. My safety folks are all over me here at the plant to determine if this is correct and if so why we do not have them on our existing plant? Safety also states the these ground wires will never last the way they are exposed in the open. Can someone help me determine if this is correct? Any code references?
1) Running a #12 or #10 ground wire from the motor frame to somewhere on the steel structure. The contractor is claiming that this is required by code and is the correct way of doing this. He is using this size wire regardless of motor size.
2) Where flexible conduit is used at the motor terminal box he is running #12 ground wire and wrapping it around, or tie-wrapping it to the flex conduit and them attaching it to the rigid conduit or somewhere on the steel structure. He claims that this is required by code to be used as a bonding jumper across the flex conduit. I argue that the flex conduit already has a bonding jumper inside but he claims this is not large enough.
Can anyone help me out in determining if either of these two practices are correct or required by code? I should mention that with each motor feed inside the conduit there is an EGC sized according per code running from the MCC ground to the motor frame. My safety folks are all over me here at the plant to determine if this is correct and if so why we do not have them on our existing plant? Safety also states the these ground wires will never last the way they are exposed in the open. Can someone help me determine if this is correct? Any code references?
