http://forums.mikeholt.com/ en Thu, 23 May 2013 02:33:23 GMT vBulletin 60 http://forums.mikeholt.com/images/misc/rss.png http://forums.mikeholt.com/ http://forums.mikeholt.com/showthread.php?t=153694&goto=newpost Wed, 22 May 2013 09:56:16 GMT I have question regarding article all of 250.30, 250.50 and 250.58. Background: I also have pictures of the installation that I could send if... I have question regarding article all of 250.30, 250.50 and 250.58.

Background:
I also have pictures of the installation that I could send if needed.
I have the contractor and his engineer telling me this is OK. I am not convinced of this.

I have a 500KW, 3 phase, 480v generator that is the stand-by power for a new building. The generator is clearly a separately derived system due to the 4 pole auto transfer switch. The grounding electrode system for the bldg. consists of the water pipe, foundation, and bldg. steel which are properly bonded and a GEC is properly terminated to the 800 amp utility disconnect main bonding jumper.
The contractor installed 2 ground rods local to the generator and did not bond to the grounding electrode system for the bldg. My opinion is that the separately derived system (the 500 kw generator) shall be connected to the same grounding electrode system for the bldg. served.

Questions.
1. Are the rod electrodes at the generator adequate to perform their intended function?
2. Does the generator need to be connected to the building's grounding electrode system?
3. In your opinion, should I pursue this further with the contractor? ]]> Grounding versus Bonding Catman800 http://forums.mikeholt.com/showthread.php?t=153694 http://forums.mikeholt.com/showthread.php?t=153609&goto=newpost Sat, 18 May 2013 15:02:55 GMT Existing 480V three phase three wire grounded "B" utility enters a 400 Amp fused service disconnect switch after the meter. "B" phase grounded at disconnect switch. 1/0 ground to water service and ground rods from disconnect. The three phase and one 1/0 ground equipment conductor enter a 400 Amp automatic transfer switch. Three phase conductors terminate on normal power position lugs of ATS. 1/0 ground equipment conductor placed on ATS enclosure lug for equipment ground. Existing 480V grounded "B" generator alternator failed and replaced with a 480V 3 phase, 4 wire WYE alternator by owner as a grounded "B" alternator is no longer available. Owner wants 480V 3 phase, 4 wire WYE on generator so if the utility service is replaced with a 480V 3 phase, 4 wire system in the future, the generator will also be 480V 3 phase, 4 wire and the system could be rewired. Existing outdoor generator has a 250 Amp circuit breaker with three 4/0 phase conductors running to the generator terminal lugs on the ATS. A #2 equipment ground conductor runs from the generator circuit breaker enclosure to the ATS enclosure equipment ground lug. Adding ground rods at the generator with a #2 ground conductor to generator circuit breaker enclosure equipment ground. Should the neutral connection on the new 480V 3 phase, 4 wire generator alternator be left floating (no connection) as it is not used (no line to neutral loads)? If left floating, the system is ungrounded and a ground detector would be installed. Essentially, when the ATS is in the normal position, the system is 480V grounded "B" three phase, three wire and when the ATS is in the generator position, the system is ungrounded 480V three phase, 3 wire. ]]> Grounding versus Bonding TBP3643 http://forums.mikeholt.com/showthread.php?t=153609 http://forums.mikeholt.com/showthread.php?t=153546&goto=newpost Wed, 15 May 2013 19:20:18 GMT Ive never ran into this situation. I am wiring a home, and the foundation is totally waterproof. Not touching the ground. there is steel rods... Ive never ran into this situation. I am wiring a home, and the foundation is totally waterproof. Not touching the ground. there is steel rods that go 20 ft into the ground that tie to the foundation, but the foundation itself doesnt touch the ground. Do I have to have a concrete encased electrode? What would meet the code for the grounding electrode system? Thanks in advance ]]> Grounding versus Bonding JEI http://forums.mikeholt.com/showthread.php?t=153546 http://forums.mikeholt.com/showthread.php?t=153489&goto=newpost Mon, 13 May 2013 18:21:01 GMT The inspector wants both afci and gfci on the same circuit. There are no grounds present in the residence and I had to repair a bad splice feeding a... The inspector wants both afci and gfci on the same circuit. There are no grounds present in the residence and I had to repair a bad splice feeding a light. Now because I touched it he wants it brought up to code. The receptacles are in cinder block and the boxes won't accommodate a gfi. Can you think of a solution? ]]> Grounding versus Bonding jiggawatt79 http://forums.mikeholt.com/showthread.php?t=153489 http://forums.mikeholt.com/showthread.php?t=153484&goto=newpost Mon, 13 May 2013 14:20:04 GMT Per NEC 250.52(A)(3)(1): “Aconcrete-encased electrode shall consist of at least 20ft of one or more bareor zinc galvanized or other electrically... Per NEC 250.52(A)(3)(1): “Aconcrete-encased electrode shall consist of at least 20ft of one or more bareor zinc galvanized or other electrically conductive coated steel reinforcingbars or rods of nit less than ½” in diameter, installed in one continuous 20ftlength, or if in multiple pieces connected together by the usual steel tiewires, exothermic welding, or other effective means to create a 20ft or greaterlength”My question… Does the electrodehave to be 20ft long, or do we just need 20ft of rod in the foundation? As stated above, code says “one continuous20ft length”, but I have others saying the “multiple pieces” part allows you tojust put any length of rod in the foundation, as long as they are tied togetherand equal a total of 20ft (not continuous). Example: a contractor claims a 5ft deep shaftw/ (4) #4 vertical bars & #4 ties meets code. That equals 20ft total, but not continuous. I say it has to be one continuous length of20 ft. What do y’all think? ]]> Grounding versus Bonding rlheflin http://forums.mikeholt.com/showthread.php?t=153484 http://forums.mikeholt.com/showthread.php?t=153476&goto=newpost Mon, 13 May 2013 00:41:17 GMT Hi. I want to know which NEC version was the first that requires the equipment bonding jumper. Since when is required? Thanks. Hi. I want to know which NEC version was the first that requires the equipment bonding jumper. Since when is required? Thanks. ]]> Grounding versus Bonding rodagana1 http://forums.mikeholt.com/showthread.php?t=153476 http://forums.mikeholt.com/showthread.php?t=153411&goto=newpost Fri, 10 May 2013 00:28:51 GMT I have a client we set up a 50 amp recep for her all electric car. She got her first electric bill and apparently it was 500.00 higher than normal.... I have a client we set up a 50 amp recep for her all electric car. She got her first electric bill and apparently it was 500.00 higher than normal. :rant: The poco said she could install a seperate
meter strictly for the car and they would give a lower rate usage on that meter. Question is if I install a meter can next to the main existing metered panel would I need a seperate GEC for it TIA ]]> Grounding versus Bonding normbac http://forums.mikeholt.com/showthread.php?t=153411 http://forums.mikeholt.com/showthread.php?t=153401&goto=newpost Thu, 09 May 2013 19:20:28 GMT The code says (in part) can use conductors with insulated green or green with one or more yellow stripes for other than equipment grounding... The code says (in part) can use conductors with insulated green or green with one or more yellow stripes for other than equipment grounding conductors.

Question; what are the other uses for this green wire ?:huh: ]]> Grounding versus Bonding rome44 http://forums.mikeholt.com/showthread.php?t=153401 http://forums.mikeholt.com/showthread.php?t=153347&goto=newpost Tue, 07 May 2013 14:48:19 GMT We are being asked to test the existing bonding of a public pool. Is there a recommended procedure for this. We plan to connect a wire to the pump,... We are being asked to test the existing bonding of a public pool. Is there a recommended procedure for this. We plan to connect a wire to the pump, stretch it out to each metal device (ladders, eyelets, etc) and record readings. In a preliminary run we had clean readings, but we also get near the same readings if we connect the megger leads directly into the earth. we don'yt trust these readings. Any suggestions? ]]> Grounding versus Bonding sevlander http://forums.mikeholt.com/showthread.php?t=153347 http://forums.mikeholt.com/showthread.php?t=153336&goto=newpost Tue, 07 May 2013 00:21:03 GMT My service ungrded cu. conductors are 350kcmil T.250.66 cals for #2awg. 250.66(A) that portion of the cond. that is the sole connection to the... My service ungrded cu. conductors are 350kcmil T.250.66 cals for #2awg. 250.66(A) that portion of the cond. that is the sole connection to the grounding electrode shall not be required to be larger than #6cu. Question: how do you work that out? In a commercial or industrial installation would you run two gec's one #2 to bldg steel the other #6 to the ground rod. ? :slaphead: ]]> Grounding versus Bonding rome44 http://forums.mikeholt.com/showthread.php?t=153336 http://forums.mikeholt.com/showthread.php?t=153312&goto=newpost Mon, 06 May 2013 17:29:29 GMT I supplied a guesthouse off a main panel that is 310 feet in distance. Do I run my two hot conductor and grounded conductor and reestablish... I supplied a guesthouse off a main panel that is 310 feet in distance. Do I run my two hot conductor and grounded conductor and reestablish grounding at the guesthouse or do I have to carry a ground from the main panel? ]]> Grounding versus Bonding Larry Shaffer http://forums.mikeholt.com/showthread.php?t=153312 http://forums.mikeholt.com/showthread.php?t=153309&goto=newpost Mon, 06 May 2013 15:25:38 GMT Can you run a pair of tens in lieu of an eight in a single run of conduit? Never thought of it before. Can you run a pair of tens in lieu of an eight in a single run of conduit? Never thought of it before. ]]> Grounding versus Bonding George Stolz http://forums.mikeholt.com/showthread.php?t=153309 http://forums.mikeholt.com/showthread.php?t=153276&goto=newpost Sat, 04 May 2013 12:56:13 GMT I have a 150 amp service in nyc residential and overhead. It was installed using 1 1/4 rigid gal. My questions are...1- do I need an insulated... I have a 150 amp service in nyc residential and overhead. It was installed using 1 1/4 rigid gal. My questions are...1- do I need an insulated neutral kit for the meter pan
2- do I bond the the threaded nippke connecting the meterpan to main breaker panel using bonding bushings
3- if using insulated neutral kit do I put the ground rod wire and cold water bond to a seperate ground bsr in panel and keep neutrals seperate ]]> Grounding versus Bonding maz2300 http://forums.mikeholt.com/showthread.php?t=153276 http://forums.mikeholt.com/showthread.php?t=153275&goto=newpost Sat, 04 May 2013 12:31:10 GMT I have a 150 amp service in nyc residential and overhead. It was installed using 1 1/4 rigid gal. My questions are...1- do I need an insulated... I have a 150 amp service in nyc residential and overhead. It was installed using 1 1/4 rigid gal. My questions are...1- do I need an insulated neutral kit for the meter pan
2- do I bond the the threaded nippke connecting the meterpan to main breaker panel using bonding bushings
3- if using insulated neutral kit do I put the ground rod wire and cold water bond to a seperate ground bsr in panel and keep neutrals seperate ]]> Grounding versus Bonding maz2300 http://forums.mikeholt.com/showthread.php?t=153275 http://forums.mikeholt.com/showthread.php?t=153218&goto=newpost Wed, 01 May 2013 23:37:55 GMT Have a Plc cabinet that is feeding 120V circuits out in the field to different devices such as pull switches, limit switches and over travel switches... Have a Plc cabinet that is feeding 120V circuits out in the field to different devices such as pull switches, limit switches and over travel switches on a conveyor system. What does the code say on how many grounding conductors per ungrounded conductors. Looks like on this project very few grounds are being pulled in. I'm seeing 20+ hots with only 1 ground for example. ]]> Grounding versus Bonding transman2 http://forums.mikeholt.com/showthread.php?t=153218