Dryers and Grounding

[skeletor]

I understand that the Neutral wire should only be bonded to the Ground system in one location to prevent improper current backflow. I just had a new dryer installed. My house has a three wire plug (neutral, hot A, hot B). The installer wired the new cord so that the neutral is grounded to the dryer cabinet, per the manufacturer instructions. I realize that dryers have been connected that way for decades, but it still seems a bit odd.

Question: If the dryer cabinet was grounded (to a water pipe, ground wire, etc,) when the cabinet is connected to neutral, would this be a bad idea?

Question 2: If a four wire cord is used, the directions suggest that the neutral and ground are connected together via the external ground cabinet screw. Doesn't this create an improper second bonding between neutral and ground? Or are appliances exempt?

[timebuilder]

You are correct, this is how it was done for decades.
However, I would take this opportunity to run a new 4 wire to the dryer. This allows you to separate the neutral and the ground, so the only time a current will flow in the ground is during a fault.

I would call customer service for that dryer, and let them know that their instructions still say to ground the neutral at the appliance. That should not be.

[54regcab]

If dryer is wired as a "3 wire" and the neutral wire opens up the cabinet becomes hot. The motor and timer both are internally wired hot to neutral

[abcreech]

I would bond as per manufacturers instructions. Most older applications wiring dryers and ranges are the same , not to current codes, but most wiring in existing home is not. By replacing your dryer with new you are not creating a different condition than what you have, however this will be done once the almighty home inspector notes it in his report should you sell your home. :