irwin%Ucb-Vax@uiucdcs.UUCP (01/25/85)
The use of the conduit as the path for the ground, and not having a 3rd wire will not pass code in most U.S. cities. The reason that the mount tabs on a duplex outlet are connected to the third terminal (the ground terminal) is so that if THERE IS NO CONDUIT, as in the way most homes are wired, the rough-in box in the wall (plaster wall, dry wall or what have you) will be grounded via the duplex mount tabs. If this were not done, the box and the screw which secures the duplex cover could be HOT and zap someone, if the hot wire inside of the box had a bare spot and was in contact with the box. With the die stamped boxes and sharp edges, it is not uncommon to happen. Since the manufacturer has no idea where the duplex outlets will end up, in a system with or without conduit, all are built alike, with the mount tabs of the duplex outlet tied to the third screw (for green wire). If your electrical system depends on the conduit and not a third wire, it is because someone cut costs but I would bet it does not meet code. The third screw was not put on the back of the outlet to hang in the air. If the outlet does not have screws, but has the holes to press the wire into, the same rule applies. The third wire is required to pass code and if it is not there, it should not be UL approved, referring to your power strip of course.
ron@brl-tgr.ARPA (Ron Natalie <ron>) (01/28/85)
> The use of the conduit as the path for the ground, and not having a > 3rd wire will not pass code in most U.S. cities. The reason that the > mount tabs on a duplex outlet are connected to the third terminal (the > ground terminal) is so that if THERE IS NO CONDUIT, as in the way most > homes are wired, the rough-in box in the wall (plaster wall, dry wall > or what have you) will be grounded via the duplex mount tabs. If this > were not done, the box and the screw which secures the duplex cover > could be HOT and zap someone, if the hot wire inside of the box had a > bare spot and was in contact with the box. With the die stamped boxes > and sharp edges, it is not uncommon to happen. > > Since the manufacturer has no idea where the duplex outlets will end > up, in a system with or without conduit, all are built alike, with the > mount tabs of the duplex outlet tied to the third screw (for green > wire). If your electrical system depends on the conduit and not a > third wire, it is because someone cut costs but I would bet it does > not meet code. The third screw was not put on the back of the outlet > to hang in the air. If the outlet does not have screws, but has the > holes to press the wire into, the same rule applies. > > The third wire is required to pass code and if it is not there, it > should not be UL approved, referring to your power strip of course. As a matter of fact, the code here requires that not only the wire be hooked up to the third screw but the box to be grounded as well, if there is no conduit.