Complex Service Entrance Mast in RMC

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If you bought 2 LBs (1 side open and 1 back open) you could use a 12" nipple between them... or if the lower one were mounted horizontally a close nipple... but it would make pulling the wires very difficult.

I'm not sure if it would help you but it is possible to shorten elbows by modifying a hand threader. Make sure to allow enough length for the threads not to be on the deformed (bent) part of the elbow, then cut off and ream the end. Remove the 4 dies from the threader and insert them backwards making sure to keep the same relative position of the dies to each other (they must be placed to cut in order 1,2,3,4 as they turn clockwise) To guide the threader I use a piece of round stock tapered at one end that I hammer into the elbow (1-1/2" pipe might work) then slide the threader on and take the piece of 2" scrap and slide it into the back of the threader to act as a sleeve to help keep the threader centered and straight. (This trick also works for making close nipples in the field if you're really desperate) :D

If it helps for $75 this makes a great hickey bender:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=32888


Can you post some photos? It'd be easier to make suggetsions if we could see the actual situation.
 
All, Thanks for all the help. After taking our discussion into consideration, I'm looking at two alternatives. Bending RMC is not going to work here, try though I may.

Option#1 - 2" RMC Mast to PVC Adapter to 2" PVC to LB to 90 degree sweep to meter can. The LB/90 Sweep has an offset of about 13". I can bring the can/Load center out an inch if I have to.

Option #2- Change the environment. Build an extension standing out from the colum until the run is straight.

I'm a smarter guy talking Rigid Bending in tight corners in this discussion. Thanks for all the comments and suggestions.
 
Something else to keep in mind: You need to maintain a minimum radius for all of your bends, so that the conductors will pull safely and easily. If a particular bend cannot have this minimum radius, then you need to make it a pull point (that is, use something like and LB). Thus you will not find something like a plumbing elbow for this application. NEC 344.24 specifies the minimum radius.

I don't have experience with custom bends. The below is from playing with a CAD program, just looking at the geometry.

If you stick with the 9.5" minimum radius for the bends, and get a 12" offset custom bent, then the minimum height required about 19", not including anystraight sections for threading.

Do an online search for 'custom conduit bending'. I'm sure you can find a supplier who will do this.

-Jon
 
mdshunk said:
Here's a couple of offsets in service masts from my album. Neither of these are my work. I take pics of work I want to make fun of. This won't help you, but it is on topic.

HPIM0543.jpg

HPIM0542.jpg
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MDS These services were approved? Where I'm from there has to be a support for the lateral... usually a 4x4 or larger or part of the bulding. We're not allowed to attach tension to the RMC.
 
DaveTap said:
MDS These services were approved? Where I'm from there has to be a support for the lateral... usually a 4x4 or larger or part of the bulding. We're not allowed to attach tension to the RMC.
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Yeah, they are both pretty new, done by the same contractor. We do support the aerial drop with a one point rack on the mast around these parts. The utility provides that fitting and does that work. I snapped these pics because in the one you can see "plumber's strapping" holding the mast near the one bend. In the other, I just thought all that Kindorf stacked up looked retarded.
 
DaveTap said:
Where I'm from there has to be a support for the lateral... usually a 4x4 or larger or part of the bulding. We're not allowed to attach tension to the RMC.
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Here the power company provides us with a nice drawing of what they will accept.

They expect the raceway to support the service drop and I think that is very common in many areas.

If the mast gets to tall they expect and specify how guy wires will be used to keep the mast verticle.

In other areas they tell you how to support a mast that comes up through a roof.
 
I made a discovery a few years ago that helped me a lot in situations like this. It was a hot day and my brain had been frying up on that roof. I needed a heavy bracket built to support a couple of mast heads. I knew that if I had a welder and some channel iron I could do it but I had neither. Then it occured to me that I had the next best thing, " money". Off I went to the welding shop that was about five miles down the road. They built the bracket for about $100.00 while I drank ice tea.

If all you need is a 12" offset then go to a tool rental place and give them $50 to let you test out a bender for a few minutes. It will be money well spent. It will cost more in gasoline driving around looking for parts ( not to mention time).

I buy conduit from a place that will thread a nipple for $5. If you buy the conduit there. If you add in these little charges up front you can spend the money and not worry about it.
 
Maybe you could use one LB and one LR with a nipple of the proper length in between. Assuming of course that everything will be exposed and accessible.
 
It sounds like the house is on a flood plan. Is that correct? The service equipment should not be on the ground level in that situation anyway. The service equipment would be on the second floor and all outlets on the first floor would be GFCI and 48" minimum above finished floor. Since it's an upgrade the rest of the house would have to be brought up to code.
 
adrian33773 said:
It sounds like the house is on a flood plan. Is that correct? The service equipment should not be on the ground level in that situation anyway. The service equipment would be on the second floor and all outlets on the first floor would be GFCI and 48" minimum above finished floor. Since it's an upgrade the rest of the house would have to be brought up to code.
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If I was doing this work, and you told me something like that, I'd have to ask you for the code citation. Feel free...
 
http://www.iaei.org/subscriber/magazine/05_d/hamilton.htm Being from Florida I have to deal with alot of new rules from the local AHJ. Most of my work recently has been on barrier islands along the west coast of Florida. In the condos we are currently building, all service equipment is on the third floor. A cat 5 hurricane can have a tidal surge of up to 25 feet which would submerge the first floor and most of the second floor. All new houses on the beach are built on columns or stilts. Only parking is allowed on the ground level. Receptacles in these condos have to be a 72" minimum above the parking garage floor. There are some new rules in the 2005 NEC that don't make a whole lot of sense yet but will become more understood in the future. The above link I was able to find in a short amount of time. I will do more research on the subject. It most likely involves local jurisdiction rather than the NEC. But alot of the rules will probably be the same for construction on rivers, lakes, canals, and around dams.
 
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This is just one of many local ordinances nationwide:

County of Lycoming, Pennsylvania
Zoning Article 5
Section 5160C Paragraph 3f.(2)

No electrical distribution panels shall be allowed at an elevation less than 3 feet above the level of the 100 year flood elevation.

That means 3 feet above the highest water level in the last 100 years. If the service equipment is existing the code does not apply. But if you upgrade the service it will have to meet code and anything attached to it will have to be moved to the new location which basically means rewiring anything below the level of that equipment. Connecticut, Massachusetts and Rhode Island have similar ordinances. This info can be found at http://www.lyco.org/lyco/cwp/view.asp?A=3&Q=417007
 
This one is for DaveTap

This one is for DaveTap

;) CODE OF ORDINANCES OF THE CITY OF FORT MYERS, FLORIDA
http://www.municode.com/resources/gateway.asp?pid=13900&sid=9
Chapter 110 Flood Prevention and Protection
Article III. Flood Hazard Reduction
Sec. 110-111. General Standards

Provision (5) Electrical, heating, ventilation, plumbing, air conditioning equipment, and other service facilities shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

Provision (9) Any alteration, repair, reconstruction, or improvement to a structure which is in compliance with the provisions of this article, shall meet the requirements for new construction as contained in this article.

Sec. 110-115. Elevated Buildings

Provision (4) Electrical, plumbing and other utility connections are prohibited below the base flood elevation.
 
I have an invention disclosure in at work that deals with flooding. I'm waiting on our IP law department to get around to releasing it for publication (we don't do residential or commercial wiring as a business, so they don't care about it, but I still have to tell them about it because they own my brain ...), which looks likely to occur before the end of the year.

I'm surprised that there's nothing in the NEC about flood-prone service installations, and the only document I found on the subject post-Katrina was from FEMA and their advice was "the building owner should disconnect the service prior to the flood".
 
Hello TallGirl

Hello TallGirl

As you probably already know the NEC is only a minimum recommended standard. The local juridiction (AHJ) has the final say and it looks like the equipment needs to be elevated above the maximum flood level pretty much any where in the country. Especially since Katrina flooded New Orleans, it will probably show up in the 2008 NEC. I have spent the last 4 or 5 hours researching Gulf Coast town ordinances and they are all saying the same thing. And this is really ironic because Monday morning I have to tell my boss that we screwed up. We are building 4 hi-rise condos on the beach. The first 2 buildings we put the service equipment on the 3rd floor. We are doing the third building now. They had some 750Kcmil/4 MC Cable that they wanted to get rid of, so they ran it down from the 3rd floor panels to the storage closet on the garage level. Then they are planning to make splices there to the service conductors coming in from the transformer. I guess that means these cabinets on ground level will have to be waterproof or floodproof. But then the MC cable itself is not waterproof so that creates another problem.
 
Based on the one NEC reference you offered (Article 682) I would continue to challenge an inspection failed with the following:

Adrian said:
The service equipment would be on the second floor and all outlets on the first floor would be GFCI and 48" minimum above finished floor. Since it's an upgrade the rest of the house would have to be brought up to code.
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Article 682 does not say this at all. I give you credit for coming up with an article that could force some of these actions, but without knowing the elevation of the electrical datum plane defined in 682.2, then pinpoint measurements like "on the second floor" and "GFCI protected, 48 in. A.F.F." are not correct. There could be no outlets allowed, or the outlets could be allowed at 8" to the bottom of the box. Without knowing the details of the site in question, it is asking to spur on "Old Wives Tale Codes" by making such blanket statements.

Adrian said:
Lycoming County Ordinance said:
No electrical distribution panels shall be allowed at an elevation less than 3 feet above the level of the 100 year flood elevation.
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But if you upgrade the service it will have to meet code and anything attached to it will have to be moved to the new location which basically means rewiring anything below the level of that equipment.
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The sentence you pulled out of their ordinances does not require rewiring the structure for a service change. I'm not saying I looked and that none of their ordinances do, I'm just saying the sentence you quoted does not do that.

Edit to add: Out of boredom, I started reading, and found this:
Lycoming County Ordinance # 5160E.3: Any modification, alteration, reconstruction, or improvement of any kind to an existing structure in any floodplain district, to an extent or amount of 50 percent or more of its market value, shall be undertaken only in full compliance with the provisions of this Ordinance.
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So, a service may be upgraded without bringing the structure into compliance, so long as the overall reconstruction project is not worth 50% of the overall value of the property before the project is started.
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Adrian said:
As you probably already know the NEC is only a minimum recommended standard. The local juridiction (AHJ) has the final say and it looks like the equipment needs to be elevated above the maximum flood level pretty much any where in the country.
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Without laws making it so, either nationally or town by town, then the AHJ has no power to enforce something like this.

Personally, I have little experience dealing with floods. But I find it hard to believe that in the event of a flood, all the utilities are flood-proof and the NEC-governed installations are behind the curve on it.
 
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First of all, the NEC is not law until it is accepted by the local jurisdiction to be such and the local AHJ has the power to make tougher ordinances in there jurisdiction. NEC is bare minimum for safety. If I wanted to I could put 8 AWG on a 20 amp breaker and it would be atleast 3 times as safe as the NEC standard of 12 AWG. With some customers money is not a problem and they would want the safest installation possible. If I was doing the job described in this thread I would check with the local building department and find out exactly what they expected before starting the job. Otherwise, if they don't like the finished project, you WILL be doing it over again.
 
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