Electrical Violation of Not?

[jar546]

Not following--the question Mr. Inspector raised was about the jumper from X0 to the terminal block on the case.

If X0 is on the secondary side, then that is an allowable System Bonding Jumper. Since you specified that the underground conduit is carrying the primary side, and that it's a step down transformer, this is the situation we have.

If X0 were on the primary (utility) side (which would make it a step-up transformer), that jumper would be a prohibited neutral-ground connection on the voltage system supplying the transformer. [Also, it would be unwise to provide a primary neutral connection to X0 at all, X0 should be left without any connection.]

So it absolutely matters which side is the primary and which side is the secondary, as far as that appropriateness/inappropriateness of that jumper.

Cheers, Wayne

There are a lot of things that are obvious about this transformer including the fact that it is an interior step down from 480 to 208. The connection of ground to neutral determines how the 1st means of disconnect will be wired on the secondary side. Seeing the connection lets you know what to expect on the secondary side as an inspector. I still don't see it as a relevant question.

 

[wwhitney]

There are a lot of things that are obvious about this transformer including the fact that it is an interior step down from 480 to 208.

Obvious if you've looked at 100 transformers, and you assume the installer is competent. Not obvious if you've only seen a few transformers

Delete both the white and green conductors connected to X0, and then from the picture only you can't tell which side is the primary and which the secondary. The voltage levels indicated by the color coding is merely a strong suggestion; the label in the lower right of the picture would clarify that, but I can't make it out.

Cheers, Wayne

 

[e hilton]

ICE said:
What’s the odds that the underground conduit has been sealed? Or would that be a violation? If it is a violation, who here would write it? Have you ever encountered a flooded building because of an underground conduit that wasn’t sealed? Only once for me.

When the cover was removed, water came out of the box. Note the mud in the box and the corroded conduit. This is in a parking garage, one level below grade, this week.

 

[ICE]

225.27
Raceway Seal. Where a raceway enters a building or structure from outside, it shall be sealed. Spare or unused race-ways shall also he sealed. Sealants shall be identified for use with cable insulation, conductor insulation, bare conductor, shield, or other components.

230.8
Raceway Seal. Where a service raceway enters a building or structure from an underground distribution system, it shall be sealed in accordance with 300.5(G). Spare or unused race-ways shall also be sealed. Sealants shall be identified for usewith the cable insulation, shield, or other components.

300.5(G)
Raceway Seals. Conduits or raceways through which moisture may contact live parts shall be sealed or plugged at either or both ends. Spare or unused raceways shall also be sealed.Sealants shall be identified for use with the cable insulation,conductor insulation, bare conductor, shield, or other components.

300.50(F)
Raceway Seal. Where a raceway enters from an under-ground system, the end within the building shall be sealed with an identified compound so as to prevent the entrance of moisture or gases, or it shall be so arranged to prevent moisture from contacting live parts.

300.50(F) could be used to argue that conduits the enter from underground with both ends within the building are required to be sealed. One application that comes to mind is conduit below a methane barrier.



300.7(A) sorta fits the condition and sorta not.

300.7(A) Raceways Exposed to Different Temperatures.
Sealing. Where portions of a raceway or sleeve are known to be subjected to different temperatures, and where condensation is known to be a problem, as in cold storage areas of buildings or where passing from the interior to the exterior of a building, the raceway or sleeve shall be sealed to prevent the circulation of warm air to a colder section of the raceway or sleeve. Sealants shall be identified for use with cable insulation,conductor insulation, a bare conductor, a shield, or other components. An explosion proof seal shall not be required for this purpose.

 

[wwhitney]

300.50(F)

is in Part II "Requirements for Over 1000 Volts, Nominal" of Article 300. So does not apply here.

300.7(A) sorta fits the condition and sorta not.

Well, if the conduits are below a slab on grade and below the insulation layer below the slab on grade, then you can certainly say that portion is "subjected to different temperatures." But in a typical inside to inside application, I don't see how condensation would be "known to be a problem." The underground conduits are expected to get wet and will require conductors with wet rated insulation. And if the two ends are at the same elevation, water's not going to start flowing out into the equipment.

Having said that, while I don't think it would be an NEC requirement to seal one or both ends, it would probably still be a good idea.

Cheers, Wayne

 

[jar546]

And is this ground running through one of the vent slots in the bottom of the enclosure? Sure appears to be.

This is the other end of what you are talking about.

 

[ICE]

is in Part II "Requirements for Over 1000 Volts, Nominal" of Article 300. So does not apply here.


Well, if the conduits are below a slab on grade and below the insulation layer below the slab on grade, then you can certainly say that portion is "subjected to different temperatures." But in a typical inside to inside application, I don't see how condensation would be "known to be a problem." The underground conduits are expected to get wet and will require conductors with wet rated insulation. And if the two ends are at the same elevation, water's not going to start flowing out into the equipment.

Having said that, while I don't think it would be an NEC requirement to seal one or both ends, it would probably still be a good idea.

Cheers, Wayne

(F) Raceway Seal. Where a raceway enters from an underground system, the end within the building shall be sealed with an identified compound so as to prevent the entrance of moisture or gases, or it shall be so arranged to prevent moisture from contacting live parts.

Note the use of the word system in relation to an underground raceway. What constitutes a system? Ten feet of RMC or is the conductor relevant in determining if a “system” exists? For the sake of convenience, my take is that the ten feet of raceway is all it takes to be a system.

Now then, the system can be so arranged to prevent moisture from contacting live parts and that would cover nearly all occasions. If find that somewhat odd in that gasses are allowed to enter if the raceway is so arranged to prevent moisture from contacting live parts..

 

[wwhitney]

(F) Raceway Seal. Where a raceway enters from an underground system, the end within the building shall be sealed with an identified compound so as to prevent the entrance of moisture or gases, or it shall be so arranged to prevent moisture from contacting live parts.

Again, that's 300.50(F), which is in the over 1000V nominal section, which does not apply to the OP.

Cheers, Wayne

 

[ICE]

Again, that's 300.50(F), which is in the over 1000V nominal section, which does not apply to the OP.

Cheers, Wayne

Oh, I didn’t pay attention to that Part 2 heading. What I wrote still applies to over 1000V. Thanks for that.

 

[jar546]

Update: still waiting for a blank cover where the original conduit came through.

 

[ICE]

You almost got witness marks... and what about the lug mounting hardware? Did the lugs come factory installed? If it was factory I'm pretty sure that they would fill the hole and that would be a different lug.

 

[Mr. Inspector]

Not sure what that round thing is attached to the meter pan. It's just a service inspection and I'm not suppose to look past the service disconnect and the grounding, but I have to look at the new panel too. But I can't say anything about the existing conduits and wiring below the new panel but I can make them get approved connectors for panel to well pipe.

 

[ICE]

"I'm not suppose to look past the service disconnect and the grounding"

I couldn't do that.







Better pictures would help. Not able to figure out what's at the top.