Suggestions for fixing an underground fed meter base falling off house

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kwired said:
Many do here as well, but I still find expansion fittings somewhat useless in many risers from underground regardless of what codes or others have to say.
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An expansion fitting will get a pass, none may not. It is that simple.

Obviously if the pipe settles more than the slack available that is a problem. However it only takes a small amount of settlement to break the glue on a PVC fitting, or pop the concentric KOs out of a meter socket. IMO an expansion fitting will address small amounts of movement. Now if the ground settles 6" an expansion fitting is not going to help.


As a side note, when I run a conduit past an expansion joint in a building I must use an expansion joint on the conduit. Where does the wire come from or go to? :) Sometimes its just easier to do what is expected without thinking to much on it.
 
Let me see if I get this right.

A common problem is outlined by the OP.

A relatively easy, inexpensive, code compliant method (expansion fittings) is suggested as the fix.

Members chime in to argue against this method.

:blink::slaphead:
 
peter d said:
Let me see if I get this right.

A common problem is outlined by the OP.

A relatively easy, inexpensive, code compliant method (expansion fittings) is suggested as the fix.

Members chime in to argue against this method.

:blink::slaphead:
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That is how it seemed to me as well. :slaphead:
 
kwired said:
Frost heave - put the buried raceway/cable below the maximum frost dept for your area. There may still be some strain on the vertical rise but there probably is some slip to it as well.

Settling - make sure to dig down to undisturbed soil and either make your underground run just as deep or compact the soil below your underground run. OP's situation is very common on newer construction where the soil next to the basement wall had been excavated to construct the basement wall. Sometimes it can take a few years before a significant rain event comes along and it suddenly settles if no compaction during backfill was performed. This also causes failures of decks, steps patios, and sidewalks sometimes.

Expansion fittings are for protecting the raceway from movement, not the conductors within. You can put some slack on those conductors if you think it will help, but start getting over about 1/0 AWG and they don't bend as easily, then put them in a cold ambient and they get even harder to bend.

A expansion joint in the OP may have saved from having the raceway pull the box loose, but if the conductors within are still being pulled it would have strained the terminations, and in that particular style of meter cabinet where conductors go straight down, probably would have pulled the box from the wall anyway, or if box were secured solid enough would have broken a lug or other components.
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Sorry but that is just pie in the sky thinking. To expect proper compaction and deeper depth of raceways on rinky dink new construction houses is unrealistic. In my area, this digging is done by other contractors working on a tight bid. We also go from extreme heat to extreme cold like most of the northern half of the country and ground heaving occurs. What you describe about proper ditches just isn't going to happen in my cases. My cost on a 2" PVC expansion is $15. That is cheap insurance against the raceway pulling out of the meter socket, and besides, it's the fastest way to comply with the code. If you installed an underground service without one in my area, you would be classified as a hack and you would not pass inspection.
 
peter d said:
Sorry but that is just pie in the sky thinking. To expect proper compaction and deeper depth of raceways on rinky dink new construction houses is unrealistic. In my area, this digging is done by other contractors working on a tight bid. We also go from extreme heat to extreme cold like most of the northern half of the country and ground heaving occurs. What you describe about proper ditches just isn't going to happen in my cases. My cost on a 2" PVC expansion is $15. That is cheap insurance against the raceway pulling out of the meter socket, and besides, it's the fastest way to comply with the code. If you installed an underground service without one in my area, you would be classified as a hack and you would not pass inspection.
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Boy, this thread took a turn for the worst. Again, not trying to pirate this thread away from the OP but it was my opinion that an expansion fitting would not have been helpful in a ground heave situation. The fitting is made for PVC expansion and contraction in variable weather climates. As far as installing one in my area, for a mere $15.00 I will install it every time on a UG service just to satisfy the EI. That doesn't mean I have to agree with him. As far as leaving slack or an "S" loop in the wire, let's remember that we're talking about 4\0 AL or 2\0 CU. Not exactly T-stat wire. :lol:
 
goldstar said:
Boy, this thread took a turn for the worst. Again, not trying to pirate this thread away from the OP but it was my opinion that an expansion fitting would not have been helpful in a ground heave situation. The fitting is made for PVC expansion and contraction in variable weather climates. As far as installing one in my area, for a mere $15.00 I will install it every time on a UG service just to satisfy the EI. That doesn't mean I have to agree with him. As far as leaving slack or an "S" loop in the wire, let's remember that we're talking about 4\0 AL or 2\0 CU. Not exactly T-stat wire. :lol:
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Exactly, the terminals in the meter socket still see the strain transferred to them from conductors being pulled on by the movement. The expansion fitting is for protecting the raceway from thermal expansion - which will be a limited amount of movement.

Frost heave - there is a reason why building footings get installed below maximum frost depth, same applies to other items that are buried.

Direct buried conductors? How do you bend an S in 4/0 that you can guarantee is not going to be pulled on when the soil around it is settling? You may get some relief but it is still going to pull some.

If you have conductor in raceway you may pull the expansion fitting apart and not put too much strain on the terminals - but only if there as enough slack on the other end of the raceway to be pulled. Your terminals still had to endure whatever pulling force was needed to pull that slack.

If you do blow and go homes, or even contract your excavating and don't take extra care because of extra cost - then you likely have other issues in the home as well that are that way because of the "cheapest way so we can land the job" approach. A lot of the time you get away with it not settling before the first year or so (when you may need to come fix it at no charge) because it may take longer then that before it settles.
 
kwired said:
Exactly, the terminals in the meter socket still see the strain transferred to them from conductors being pulled on by the movement. The expansion fitting is for protecting the raceway from thermal expansion - which will be a limited amount of movement.

Frost heave - there is a reason why building footings get installed below maximum frost depth, same applies to other items that are buried.

Direct buried conductors? How do you bend an S in 4/0 that you can guarantee is not going to be pulled on when the soil around it is settling? You may get some relief but it is still going to pull some.

If you have conductor in raceway you may pull the expansion fitting apart and not put too much strain on the terminals - but only if there as enough slack on the other end of the raceway to be pulled. Your terminals still had to endure whatever pulling force was needed to pull that slack.

If you do blow and go homes, or even contract your excavating and don't take extra care because of extra cost - then you likely have other issues in the home as well that are that way because of the "cheapest way so we can land the job" approach. A lot of the time you get away with it not settling before the first year or so (when you may need to come fix it at no charge) because it may take longer then that before it settles.
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You sound like you do not live in the real world.

Here again is the current NEC requirement.

2014 NEC said:
300.5(J) Earth Movement. Where direct-buried conductors,
raceways, or cables are subject to movement by settlement
or frost, direct-buried conductors, raceways, or cables shall
be arranged so as to prevent damage to the enclosed conductors
or to equipment connected to the raceways.


Informational Note: This section recognizes "s" loops in
underground direct burial to raceway transitions, expansion
fittings in raceway risers to fixed equipment, and, generally,
the provision of flexible connections to equipment subject
to settlement or frost heaves.
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If an inspector asks you how you are complying with it what is your answer?

I am not interested in what you think of the requirement, I am simply asking how you would comply with this section.
 
iwire said:
You sound like you do not live in the real world.

Here again is the current NEC requirement.



If an inspector asks you how you are complying with it what is your answer?

I am not interested in what you think of the requirement, I am simply asking how you would comply with this section.
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Unless you are using a more modern UG meter pan that allows you to provide a service loop I don't see how we can comply. BTW, are we as electricians subject to following informational notes or are they just suggestions ?
 
Where direct-buried conductors, raceways, or cables are subject to movement by settlement or frost
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I guess our area is not an area that suffers the movement problem, above. We don't do anything but run the pipe and bury it, and the inspectors don't gig people on it. I'll bet if I took a ride and looked at UG risers in my area, I wouldn't find a single one with an expansion fitting.
 
iwire said:
You sound like you do not live in the real world.

Here again is the current NEC requirement.



If an inspector asks you how you are complying with it what is your answer?

I am not interested in what you think of the requirement, I am simply asking how you would comply with this section.
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If I have undisturbed or compacted soil below the raceway or cable it is not subject to settling.

If I bury the raceway or cable below the frost line it is not subject to frost heave.

If I have enough length that there is more then 1/4 inch of thermal expansion/contraction I still need an expansion fitting on PVC. For my area I have calculated that we can likely get by with 3 feet or less and not need an expansion fitting for the thermal expansion requirements. Most of my farm work that doesn't get inspected I don't use them unless we have more then 3 feet emerging from the ground - and very rarely have I had broken fittings because of thermal expansion, frost heave, or settling, that I am aware of, as long as I followed the other practices of installing on undisturbed or compacted soil and buried below frost line.

If I used RMC/IMC to emerge from the ground they would never question it at all even though frost heave or settling risks are the same as they are for PVC, and sometimes I do that in higher abuse areas.
 
I don't see frost heave or large temperature swings here. Average temperature swing through the year is about 25 degrees F. I suspect a garbage bag w/ some styrofoam peanuts on top of the bend might provide some extra freedom from movement. Also, if the wire is laying in the bottom of the conduit, doesn't it have a little room to move as the expansion fitting is extended.
 
Barbqranch said:
I don't see frost heave or large temperature swings here. Average temperature swing through the year is about 25 degrees F. I suspect a garbage bag w/ some styrofoam peanuts on top of the bend might provide some extra freedom from movement. Also, if the wire is laying in the bottom of the conduit, doesn't it have a little room to move as the expansion fitting is extended.
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If what is below the conduit settles, weight above conduit will still pull it down, I doubt you are filling entire trench with foam peanuts.

If what is below the conduit is pushed up by frost heave, the conduit still gets pushed up.

Unless you are putting 3- 4/0 conductors in a 4 inch + raceway how much movement do you expect to get from free space in the raceway?
 
When I terminate the conductors at the meter terminals on an UG service I will push down the cables as far as I can into the conduit 90 then pull up a little, mark, strip and terminate them which I hope will be enough to handle any expanding.
 
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