April 30th, 2020, 8:01 am
April 30th, 2020, 9:13 am
Stuart Polansky wrote:8 foot ground rods should be considered supplemental only. Their impedance is ridiculously high; no matter how large the service (even 4000 amperes) the grounding electrode conductor to a driven rod never needs to exceed #6 AWG copper!!!!! The rod simply cannot conduct any more current.
Want a good ground besides the superb cold water ground? Use a Ufer ground. That is a foundation ground. If there isn't one in your house, the procedure is to dig a 20 foot long, two foot wide by two foot deep hole, install rebar, Cad weld the GEC to the rebar, and encase the assembly in concrete. That is a low impedance ground.
If you are going to drive a shitty ground rod and connect it to your stereo, consider this . Unless, you have a separately derived system (transformer coupled, galvanic isolation, no current path between primary and secondary windings) the ground you add is in parallel with the household grounding electrode system as well as the utility center tap of the transformer feeding the service.
So, if a ground fault occurs anywhere between the transformer and any branch circuit in the house, a portion of the fault current WILL flow through your stereo ground, perhaps right through your tonearm!
There are good reasons for the Code rules. Flout them at your own risk.
ALL GROUNDS IN A STRUCTURE NEED TO CONNECT TO THE GROUNDED CONDUCTOR (NEUTRAL) AT A SINGLE POINT UNLESS WORKING WITH A SEPARATELY DERIVED SYSTEM!
April 30th, 2020, 9:27 am
tomp wrote:You want to hear crazy? I was speaking to an electrician in an older section of PA who said they used to use the ground as a neutral. No, that is not bonding the neutral and ground at the box, but actually using the ground as the second current carrying wire. That is as bad as the common practice among boneheads that have a backup generator and feed it into a dryer outlet, using the ground at the three wire socket as the neutral for the 120 volt circuits. And to add salt to the wounds they have no transfer switch and try to remember to trip off the main service disconnect.
April 30th, 2020, 11:58 am
April 30th, 2020, 1:10 pm
tomp wrote:Here is the spec for "breakers" in my new house under construction. As you mentioned they are arc fault interrupters that look for high frequencies on the line caused by arcing.
April 30th, 2020, 1:23 pm
April 30th, 2020, 2:05 pm
tomp wrote:I spoke to a couple of electricians who said certain appliances like vacuum cleaners drive the arc fault suppressors crazy. One of the electricians said when working on new construction where contractors are using saws with electric brakes, he installs regular breakers while they are working or the interrupters would trip repeatedly when they stop the saws. When they are finished he goes back and replaces the standard breakers with interrupters. They are another case of good ideas with unforeseen consequences.
April 30th, 2020, 4:12 pm
tomp wrote:I spoke to a couple of electricians who said certain appliances like vacuum cleaners drive the arc fault suppressors crazy....
April 30th, 2020, 5:23 pm
tomp wrote:You want to hear crazy? I was speaking to an electrician in an older section of PA who said they used to use the ground as a neutral. No, that is not bonding the neutral and ground at the box, but actually using the ground as the second current carrying wire. That is as bad as the common practice among boneheads that have a backup generator and feed it into a dryer outlet, using the ground at the three wire socket as the neutral for the 120 volt circuits. And to add salt to the wounds they have no transfer switch and try to remember to trip off the main service disconnect.
April 30th, 2020, 5:47 pm