<![CDATA[Mike Holt's Forum - NEC]]> http://forums.mikeholt.com/ en Wed, 22 May 2013 04:35:47 GMT vBulletin 60 http://forums.mikeholt.com/images/misc/rss.png <![CDATA[Mike Holt's Forum - NEC]]> http://forums.mikeholt.com/ Heaters for swimming pools http://forums.mikeholt.com/showthread.php?t=153692&goto=newpost Wed, 22 May 2013 02:59:29 GMT Does article 680 require GFCI protection on a 240v heat pump which is being used to heat the water of an in ground perm. pool. Most electricians... Does article 680 require GFCI protection on a 240v heat pump which is being used to heat the water of an in ground perm. pool. Most electricians state that they read "all associated pool equipment shall have GFCI protection". Article 680 is very specific when it comes to GFCI protection of each individual piece of equipment of a pool installation, except for the pool heaters. Would have thought 680.9 would have required GFCI protection. ]]> NEC MrBreeze http://forums.mikeholt.com/showthread.php?t=153692 Simple motor controller question. http://forums.mikeholt.com/showthread.php?t=153688&goto=newpost Wed, 22 May 2013 01:40:26 GMT Hi, guys. I did not have experience with motors for the past few years and tomoro i will have to install a timer for 5 amp 120v indoor exhaust fan.... Hi, guys.
I did not have experience with motors for the past few years and tomoro i will have to install a timer for 5 amp 120v indoor exhaust fan. that would make it 1/4 hp i guess.
the timer is going to be adjacent to fan and it's disconnect in commercial application.
my Q is;
is that timer concidered a controller and does it have to have disconnect? i wanted to install a decora style device for motor loads. if it has integral off option would that count?
i could have it on load side of motor disco but that would knock it off real time or reset after turning disco off.
thanks for this forum and it's members ]]> NEC darekelec http://forums.mikeholt.com/showthread.php?t=153688 240V Receptacle to breaker matching http://forums.mikeholt.com/showthread.php?t=153683&goto=newpost Tue, 21 May 2013 20:44:15 GMT Just when I need my 2008 NEC book, it eludes me... I presently have a branch circuit with 10/4 cabling, a 30A double-pole breaker, and a 30A... Just when I need my 2008 NEC book, it eludes me...

I presently have a branch circuit with 10/4 cabling, a 30A double-pole breaker, and a 30A L14-30R (250V/125V) receptacle that serves an electronic equipment rack. 30A is well over-rated for the acrtual use. I am going to start using a UL-compliant 240V RPT that is limited to 20A connectors per UL RPT guidelines. Here's my question:

If I change the serving wall receptacle to a single 20A L14-20R, must the serving breaker also be rated 20A or may I leave the existing 30A breaker? My gut tells me NEC will require alignment of a 20A breaker for use with a single 20A receptacle. Gut right or wrong? Tnx!

Paul ]]> NEC RFEngineer http://forums.mikeholt.com/showthread.php?t=153683 Flex connectors unsupported in switchgear http://forums.mikeholt.com/showthread.php?t=153682&goto=newpost Tue, 21 May 2013 20:35:29 GMT 3" flex was run from the 800 amp, 480V switchgear through the 2nd floor to a Jbox in the ceiling below. In the switchgear, the core and KO in the floor of the switchgear are the same diameter, which is also too small for a 3" flex connector. As you can see in the picture, the electrical contractor installed the flex connector, but has it resting on the bottom of the switchgear, unsupported.

I couldn't find any code violation, but I do believe that a bonding bushing on the flex connector is required. Not sure why they didn't at least install EMT sleeves through the floor and then convert to flex instead. Can you guys comment on the install?

Thanks!


PS - Sorry if the picture is too large for some, it looks just right on my screen.

Attachment 8572
Attached Images
 
]]> NEC Will B http://forums.mikeholt.com/showthread.php?t=153682 Transformer Clearance http://forums.mikeholt.com/showthread.php?t=153679&goto=newpost Tue, 21 May 2013 18:35:06 GMT According to the NYC DOB 2012 Code Revision and Interpretation Committee Code Interpretation... According to the NYC DOB 2012 Code Revision and Interpretation Committee Code Interpretation:

Section 110.26(F) - (4/4/2012)

Q: In an electric closet we are required to provide a ceiling mounted 45 KVA transformer. Section 110.26(A) requires a minimum working space of 3 feet.

a. Does section 110.26 (A) & 110.26(A)(1) pertain to ceiling mounted transformers?
b. Since the transformer will not likely require adjustment, servicing, or maintenance, does section 110.26(A)(1) apply?

A. a. Yes, Section 110.26(A) requirements apply to all electrical equipment to permit ready and safe operation and maintenance of such equipment. Also, transformer accessibility per section 450.13 must be provided.

b. Yes, Section 110.26(A)(1) requires such working space for equipment that likely to require examination, adjustment, servicing or maintenance while energized. See excerpt from NEC 2008 Handbook in regard to examination inclusions:

“It is important to understand that the word examination, as used in 110.26(A), includes such tasks as checking for the presence of voltage using a portable voltmeter.”

Do you agree? ]]> NEC ASG http://forums.mikeholt.com/showthread.php?t=153679 Garage outlet circuits http://forums.mikeholt.com/showthread.php?t=153678&goto=newpost Tue, 21 May 2013 18:19:53 GMT Since kitchens and bathrooms have a requirement to have outlets on a separate 20-amp circuit with no lights or other outlets on them, why doesn't the same rule apply to outlets in a garage or outdoors? It would make sense, using the same logic for the reason why kitchens and baths need them. Garages are where people plug in power tools, so you wouldn't want to run them on 15-amp circuits, especially if they are part of a general lighting circuit. Same for outdoors -- yard tools, Christmas lights, etc. can also draw a lot of power which can overload a general lighting circuit. Whenever I wire garages and houses, I always wire all the garage outlets to a separate 20-amp circuit, and I wire an additional one for the outdoor outlets as well. All GFI protected, of course. ]]> NEC jeff48356 http://forums.mikeholt.com/showthread.php?t=153678 Neutral to first disconnect question http://forums.mikeholt.com/showthread.php?t=153677&goto=newpost Tue, 21 May 2013 18:10:30 GMT Situation is we are temp feeding some service gear with a temp generator skid. 480/277. Grounded conductors in the system stop at this gear, first... Situation is we are temp feeding some service gear with a temp generator skid. 480/277. Grounded conductors in the system stop at this gear, first disconnect. We are feeding with DLO 4/0 cables. 8 per phase. 2 for grounding conductors.

Originally I was told no grounded conductor, but when I got there I realized it was the first disconnect and I need to bring my neut and land it. I am planning on bringing only 1 (4/0) to bond.

My question is do I need to match my 2 grounding conductors and bring 2 neutrals over or can I get away with 1? Inspection later this afternoon. Mind you this will all be taken apart and put back together in the original configuration around 3am tomorrow morning.

Thanks.

Edit to add, there is NO load on the grounded conductor. ]]> NEC paul http://forums.mikeholt.com/showthread.php?t=153677 Plug-in connections inside industrial control panels, code violation? http://forums.mikeholt.com/showthread.php?t=153676&goto=newpost Tue, 21 May 2013 17:40:46 GMT I am doing a design review on another engineer's control panel design. He has a desktop UPS plugged into a DIN-rail 120 VAC receptacle and several "wall-wart" power supplies plugged into the UPS receptacles.

I don't think this is a good idea. I have found the following sentence in an Allen-Bradley hardwired UPS sales brochure:

"Electrical codes typically do not allow plug-in connections within a control panel."

I have been unable to find any reference to this in my copies of NEC 2008, UL-508A 2001, NFPA-79 2007.

Does anyone know what section(s) of the codes cover plug-in connections on an industrial control panel? Any help appreciated! ]]> NEC cerskine http://forums.mikeholt.com/showthread.php?t=153676 Primary Feeders http://forums.mikeholt.com/showthread.php?t=153675&goto=newpost Tue, 21 May 2013 17:15:02 GMT Does anyone know off the top of their heads if there is any code preventing primary sheilded feeders from being placed in PVC schedule 40 PVC. Seems... Does anyone know off the top of their heads if there is any code preventing primary sheilded feeders from being placed in PVC schedule 40 PVC. Seems like 80 is the minumum but cant find the article.

Also, I have a situation where a customer has fed from an S&C switch to a fire pump transformer, then jumped out of the fire pump transformer to the main service transformer . The fire pump xfmr is 300kVA. The main xfmr is 1500KVA. The wire is sized for 1500kVA and fed to accomodate the 1500kVA. Basically the 300KVA is used as a feed through. I feel like it is sound from a design standpoint but i don't like it. I'm more worried about the firepump requirements as for being independent feeder. ]]> NEC aelectricalman http://forums.mikeholt.com/showthread.php?t=153675 Motors on SO cord http://forums.mikeholt.com/showthread.php?t=153670&goto=newpost Tue, 21 May 2013 13:58:05 GMT I'm sure someone can help me out here...I am trying to determine if the Code will allow small (less than 2HP) 3 phase ac motors to be permanantly installed using flexible type cord (ie SO) and use a "listed for use" (as in 430.109(F)) attachment plug and cord connector?
I guess my question really goes back to Flexible Cords, Uses Permitted 400.7(6) and 400.7(10). These motors are driving pumps in an industrical facility. 400.7(6) cites "frequent interchange", but what is considered "frequent"? Also, 400.7(10) cites "where specifically permitted elsewhere in this Code". Ok, since 430.109(F) discusses Cord and Plug connected motors, does that allow the motors to be installed using cord and plug as long as the conditions of 430.109(F) are met? Thanks for the help. ]]> NEC Just_Sum_Guy http://forums.mikeholt.com/showthread.php?t=153670 Combining refrigeration appliances http://forums.mikeholt.com/showthread.php?t=153669&goto=newpost Tue, 21 May 2013 13:42:29 GMT A refrigeration appliance has 4.1 amps with max OCPD 15 amps. Another appliance has 2.3 amps with no max OCPD. Can both of these go on one 15 amp... A refrigeration appliance has 4.1 amps with max OCPD 15 amps. Another appliance has 2.3 amps with no max OCPD. Can both of these go on one 15 amp circuit breaker? ]]> NEC cppoly http://forums.mikeholt.com/showthread.php?t=153669 LG Mini-Split HVAC Unit http://forums.mikeholt.com/showthread.php?t=153667&goto=newpost Tue, 21 May 2013 11:28:40 GMT Inspected a job with a new LG Mini=split AC Unit. The contractor had used SJO cord to connect the interior and exterior unit. The cord was ty-rapped... Inspected a job with a new LG Mini=split AC Unit. The contractor had used SJO cord to connect the interior and exterior unit.
The cord was ty-rapped to the insulated condenser lines, run thru the attic & walls and terminated at each unit.
I rejected it based on 400.8 (1)(2)(4)(5).
The E/C advised it was installed per manufacturer's instructions which state:

3. Use outdoor and waterproof connection cable rated more than 300V for the connection between
indoor and outdoor unit. (For example, Type SJO-WA)

Of course, the instructions also stated to comply with ALL CODES which would include 400.8.

My post is in regard to these instructions. I failed to check the listing on the LG unit but think they might be CSA listed and manufactured in Canada. For any who might be familiar with Canadian Codes, would such an install (Using cord) be acceptable under Canadian Code ?
• ]]> NEC augie47 http://forums.mikeholt.com/showthread.php?t=153667 Heavy Duty/Normal Duty http://forums.mikeholt.com/showthread.php?t=153664&goto=newpost Tue, 21 May 2013 03:04:43 GMT Got my 200 HP normal duty Vfd today, and also got the 250 HP heavey duty. Same unit. Not one manual. Nothing but a line diagram for the control.... Got my 200 HP normal duty Vfd today, and also got the 250 HP heavey duty. Same unit. Not one manual. Nothing but a line diagram for the control.

I will be using it as the normal duty 200 HP rating...this year. Next year they may run it at the 1.15 SF of the motor. What do I size my incoming wire at? 1.25 * ND or HD? ]]> NEC ptonsparky http://forums.mikeholt.com/showthread.php?t=153664 <![CDATA[Um...... maybe I'm wrong......]]> http://forums.mikeholt.com/showthread.php?t=153662&goto=newpost Tue, 21 May 2013 01:34:07 GMT .......... but...............



... don't you need NEMA 3ph receps for 3-phase circuits?



]]> NEC 480sparky http://forums.mikeholt.com/showthread.php?t=153662 Inspectors and 550.32 http://forums.mikeholt.com/showthread.php?t=153661&goto=newpost Tue, 21 May 2013 01:05:34 GMT Is there a time when a meter base can be attached to the side of a mobile home? In the last week I have run into two different mobile homes in two... Is there a time when a meter base can be attached to the side of a mobile home? In the last week I have run into two different mobile homes in two different counties(different inspectors) that have had the combo panel attached directly to the side of the mobile home.

Am I reading something wrong?

I know one will be getting a brick foundation, but that doesn't change the definition in 550.2 IMO. The other one will be getting the vinyl underpinning only. ]]> NEC http://forums.mikeholt.com/showthread.php?t=153661