You’re the lead electrician at a plant with a 15-person maintenance crew. Eric, the maintenance manager, is a mechanical engineer. The plant recently hired a new plant engineer, Peter, who is an industrial engineer by training.
Eric called you into his office and said he was very disappointed in you for not doing your job. “When my new boss chews me out for grounding deficiencies in the finishing and packing areas while my lead electrician never noticed these, I tend to get a bit upset,” he tells you.
Eric said he had considered firing you on the spot, but he’s giving you a day to come up with a plan for fixing all of these as soon as possible.
What is the real problem here, and what should your response be?
Answer to Quiz. You may have noticed that Chapter 1 of the NEC begins with Art. 100. And Art. 100 contains a huge number of definitions. It’s not a glossary stuck in the back, but rather, it's a comprehensive compilation of definitions right up front. Why do you think this is?
The intent is that everyone speaks the same language. When you move past Art. 100 (after having taken the time to become familiar with the definitions contained in it), you won’t be in the position of thinking one thing when the Code rule means something else.
During the conversation (such that it was), you should have asked Eric if he asked Peter what Peter meant by “grounding” and to give an example of deficiencies. Eric failed to do this and instead jumped to the conclusion that you were a bad employee.
First go out to those two areas of the plant and identify any separately derived sources (SDSs), such as a transformer supplying those areas. If those are correctly grounded, there are no grounding deficiencies. If any are not grounded, and this is very unlikely, assign someone to ground them. Let’s assume they are all grounded, since that is almost certainly what you would find.
So now go back to Eric with a copy of the NEC and say you need some clarification before talking with Peter because you didn’t find any grounding deficiencies in those areas (or if you did find an ungrounded SDS, this hardly makes for the crisis Eric described earlier).
First, turn to Art. 100. Read the definition of ground. Then point out this applies only to (in this situation) transformers. Ground rods and other connections to the earth are not required for other kinds of equipment and in fact serve no electrical purpose if they exist.
Then explain it may be the case that Peter expected ground rods to be driven at every motor, and you want to talk with him to determine exactly what he meant. Now you’ve given Eric a quick tutorial and not bypassed him in getting this sorted.
Before you meet with Peter, do a walk-through to look at the equipment grounding (bonding) conductor (EGC) system. If raceway is being used as the EGC, is it mechanically and electrically continuous? Are bonding jumpers missing between large metallic objects and the EGC? Are any of the items listed in Sec. 250.118(B) used as part of the EGC, or do all such items conform to 250.118(A)?
You may find some EGC deficiencies, and if so then note them. If the quantity is small or non-existent, you’re ready to meet with Peter.
Begin by thanking Peter for caring about the electrical systems, especially in relation to making sure things are adequately grounded. Then ask if “…we can agree to use terms as defined in the National Electrical Code to ensure that we’re speaking the same language.” This is a reasonable request he should readily agree to. Show him the definition of ground.
Then say the NEC also specifies how this applies to equipment. Since he already agreed to use the definitions in the NEC, he has pretty much agreed to abide by the NEC. He’s not going to want to sit through a whole tutorial, and since you’re the lead electrician you already have the position of having the expertise in the NEC.
You can say that the NEC doesn’t require anyone to make dirt connections on the load side, those are for the supply side. On the load side, we bond and that means creating a metallic path between objects to prevent objectionable current flow. Grounding does not and cannot accomplish this, which is why something like a ground rod on a motor is electrically pointless. Then add a face-saving comments such as, “But you’d have to be an electrical geek to know that.” Ask Peter if motors without ground rods are what he’d meant or if it was something else.
It was probably this, and if so then thank him for the discussion and ask if there’s any other concern he has. He probably has no clue about the EGC, but if he brings this up, you are already prepared.
Wrap up by letting Eric know there was a big misunderstanding, and Peter is happy now. Also let him know you are not happy with his reactive way of communicating to you. Request that in the future, he avoids shooting first and asking questions later.
