I, an upcoming home inspector, proceeded to inspect my daughters for sale house…cool deal for her, and I get a practice run. So right away I encounter an oddball situation (I think…maybe experienced inspectors see this stuff lots) I locate the service entrance and there are two 100 amp boxes side by side so I went into the service panel looking for neutral and ground bus bars…there is only one, with both neutral and ground wires attached. So I assume that amounts to being bonded but with only one bar. I can find no attachment to the enclosure, nor can I find any earth ground. Were things actually done like this, or is there some tricky things that are not in the books. So in the adjacent distribution box there are all double pole breakers for base heaters. These are hooked up with regular three wire (black, white, ground) and there is no neutral…which Ive read gobs of stuff about how you dont need a neutral with 220 but ill be darned if i can ‘get it’…guess for me its just one of those things i have to accept the concept whether or not I understand. Anyone who would like to cast some light on all that out of experience and/or knowledge…thanks!
Service entrance panel can have grounded (neutral) conductors and grounding (ground wires) on the same bus. In fact, if on different buses, they should be bonded together.
Lack of a visible bond to the cabinet and lack of a visible GEC should be deferred to an electrician. (Sometimes GEC is in conduit and not visible.)
Maybe the neutral/ground bus was bolted to the enclosure. The GEC could be missing, fairly common problem. Always post pictures when asking electrical questions since terminology and understanding affects how questions get asked. Most new inspectors are weak in electrical and HVAC, you will need to study hundreds of hours for several years.
As far as not understanding 240V with no neutral, look up alternating current and think “push-pull” on the waveforms. Its called single phase but has opposing phases that act as “returns” for each other.
hey Joe thanks for the reply. Yes service panel needs bonding I suppose Im just naively thinking things will look like in the book…ie neutral bar on one side and ground bar on the other and then some variety of the bonding attachments i saw in the tidy book pictures. Instead I found one bar which furthermore appears to be located on top of plastic ‘feet’ thereby defeating any bar to enclosure bond and and then no earth ground and the 220 thing…and i thought dang i thought everything would be like the pictures (my little joke…not really) but this is how i learn by listening to others’ experiences
You will find that the “books” have barely scratched the surface of what you will encounter as an inspector.
Now you should hire an experienced home inspector to inspect your daughters house and then compare your notes.
I agree with Mark - although another thought is to find a Master Electician (although sometimes that is a misnomer) and have him look at and explain what you are seeing.
Don’t feel bad - there is so much about electricity that is confusing. Take all the NACHI courses, check this BB and find other BBs that will help. And never think you know it all.
How about posting some photo’s of you daughters service so we can take a look at what you’re seeing. It might be beneficial to you if we can critique the panel and give you some insight into what you should be looking at.
thanks for all the input…i value this from more experienced folks of the field. there was enough suspect stuff so we actually called in an electrician and i got to ask some questions and learn some stuff…still dont get the 220 but that will come
240 volts is not complicated. Think of two 1.5 volt batteries in series (connected end to end). Forget polarity for minute, if you test from one end to the other you’ll get 3 volts. If you test from either end to the center where the two batteries meet you’ll get 1.5 volts. Same principle applies to a 3 wire, 120/240 volt system. Think of it as two 120 volt batteries connected again in series, end to end, You would have 240 volts across the ends and from either end to the center point you would have 120 volts. In the 120/240 volt system the center point between the two would be your Neutral.