said by alkizmo: said by nunya:
If the dryer plug is 3 prong, then the neutral and ground must be bonded together at the dryer.
I understand this is how it was done in the past.
This is out of curiosity, but I know that it's a big no-no to have a second N/G bond, and in this case, this would be one.
What's the risk for the rest of the house at this point?
If there is only 3 wires, it's not a 2nd neutral-ground bond. It's just the neutral touching itself.
It would be a problem if it was a 4-wire plug and the strap/wire was connecting the neutral and ground at the dryer. The problem is the same problem that would affect a sub panel that didn't have the bonding jumper removed between the neutral and ground buss bars.
A possible scenario would be if equipment grounds and neutrals are tied to different buss bars at the panel. The equipment ground buss bar is directly attached to the wire headed to the ground bar. The main bonding jumper between the ground and neutral buss bar becomes loose or otherwise separates. If the dryer was 4-wire with the N-G bonded at the dryer, any current from the neutral bus bar would flow through the dryer's neutral, back to the panel with the dryer's equipment ground, and then to the ground rod. Well, it would do that until the wire melted or the house burned down.
Farfetched example, but it could happen. And I'm sure there are many homes that are improperly installed. The only saving factor is that in order for the problem to show itself, something bad has to happen elsewhere.