Hello again ,Ihave a question about a service I did last week. The new service is a 200 amp 30circiut SQD.The old service was a 100a SQD ,the homeowner complained that every time the a.c. kicked on his lights would dim the same thing happens when the pool filter is turned on.The old panel had 4 tandum breakers in it with a total of 18 circuits . While doing the final connections I went to connect the grounded conductor and the old stranded wire pulled right out. This was one of the problems, I attached the new wire to poco wire . I notice the problem still exist, I checked all my connections they were tight. I took a amp reading L1=22 L2=28 N6 amps and the wire going to the water pipe was reading 4.8amps .After asking the homeowner if POCO did any work in the area he said YES a car hit a pole across the street a cracked it .They put a new pole about 5ft over ,but all thier connections are in the same spot. I told the homeowner after it is inspected tell the POCO's service truck to check thier connections .Also the wire going to the ground rod had 0 amps,this I don't understand .Any input would be helpfull.
John, everything is new from service head to the panel . the old wire pulled out of the POCO crimp. Also the water meter is 20ft away from the panel the ground wod is 8ft away but no amp reading . got to go to work check in the morning thanks
Re: service-volts on waterpipe ground wire#13395 09/02/0211:13 PM09/02/0211:13 PM
If what you are wondering is why there seems to be no current on the wire to the ground rod that would be because it is a much poorer path for current to flow back to the source. The current is trying to get back to the source (transformer) and the waterpipe is a much better path than the earth itself, so more current will flow on the waterpipe. (It could be going through the water pipe to the house next-door and through their service neutral) Some will flow thru the ground rod but perhaps less than your meter can measure.
[This message has been edited by Bill Addiss (edited 09-03-2002).]
Re: service-volts on waterpipe ground wire#13396 09/03/0207:19 AM09/03/0207:19 AM
Current will always be carried by the metal underground water piping system where the water pipe system interconnects a number of buildings. Each house has the grounded conductor bonded to the common metal underground water piping system. This places the water piping system in parallel with the grounded conductors. This current is not related to the voltage dip problems that you are experiencing. Don
Re: service-volts on waterpipe ground wire#13397 09/03/0204:53 PM09/03/0204:53 PM
Andy, You are correct that a poor connection on the grounded conductor will cause more current to flow on the water pipe. The current that you measured on the water pipe might even becomming from another house. Did you measure the water pipe current with the service disconnect open? Don
Re: service-volts on waterpipe ground wire#13399 09/03/0209:18 PM09/03/0209:18 PM
I don't have alot of residential experience but have been in the industrial setting for 8yrs so bear with me here. My question is if i take out all the copper water lines or most of them in my house and go to PVC does this create a problem with the water pipe grounds.
Re: service-volts on waterpipe ground wire#13400 09/04/0210:04 AM09/04/0210:04 AM
There are two possible answers. The water pipe coming into your house, as long as it stays metal, will be unchanged in what it does as the Grounding Electrode (250.52).
Part two: any equipment grounds for fixtures or outlets that were connected to the interior water pipe (back when it was allowed) will now have to be rerouted to the electrical system EGC. The remaining metal pipe that you don't replace will need to be bonded according to 250.104.
Re: service-volts on waterpipe ground wire#13401 09/04/0209:54 PM09/04/0209:54 PM
ok, thanks for the info. alot of the house has been converted to pvc but i think my 5 and 9yr old could have done a better job. and when i put in a new 200amp service i am planning on looking over the entire house and fixing any problem areas. shouldnt be to hard the house was built in 65 and it is single story small ranch with panel in basemant so you can follow most runs fairly well.