Another:A Seal or no Seal

[Al Pike]

The Engineered C1 D1 design was to run the pump pwr. and floats into two 4x plastic boxes embeded into the pump station lid.The cords are connected with plastic strain relief connectors to the bottom of the boxes.The boxes have 1-1.5 rigid conduit each embeded in the lid 12'' to the rim outside the C1D1 area.

My question is can I pass the cords through the boxes and conduit unspliced,and connect the cords to my pump panel that is mounted on a rack next to the pump station without a seal on the 1.5 conduit.I dont see the need for a seal. Thanks.

 

[Buck Parrish]

As I am picturing what you have described, if air can get out. You must seal.

As the tank rises it pushes air some where. Better through the sewer vent then electrical boxes.

 

[jwjrw]

We seal all condiuts to control panel on both ends.

 

[rbalex]

The Engineered C1 D1 design was to run the pump pwr. and floats into two 4x plastic boxes embeded into the pump station lid.The cords are connected with plastic strain relief connectors to the bottom of the boxes.The boxes have 1-1.5 rigid conduit each embeded in the lid 12'' to the rim outside the C1D1 area.

My question is can I pass the cords through the boxes and conduit unspliced,and connect the cords to my pump panel that is mounted on a rack next to the pump station without a seal on the 1.5 conduit.I dont see the need for a seal. Thanks.

I'm sorry, I've reread this post a half-dozen times to attempt to picture the installation, but I haven't been able to get past the "two 4x plastic boxes" and "cords" in a Class I, Division 1 area.

 

[petersonra]

I'm sorry, I've reread this post a half-dozen times to attempt to picture the installation, but I haven't been able to get past the "two 4x plastic boxes" and "cords" in a Class I, Division 1 area.

That caught my eye as well.

maybe the cords come up a piece of rigid and then exit the rigid above the D1 boundry and enter the plastic boxes outside the D1 area. IMHO, you need a seal at the end of the rigid if that is the case.

I am having a hard time enviisoning just what he has there.

 

[cadpoint]

How about a Barrel Lid Cap with a 12" RMC (stove pop) into or out of the plastic below. A raceway to the underside of lid or into the barrel that happens to connect be plastic?

 

[Al Pike]

Ok I'll try to lay it down.The 4x,12''x6''x6'' boxes are embeded into the outer edge of a 5'' thick concrete lid,with the bottom of the box flush with the inside of the pump station and the top sticking out 1'',not including the cover.There is 1-1.5''x12'' rsg nipple KO'd from the side of the box to the outside edge of the lid to the open air.The bottom of the boxes were KO for 3/4 strain relief fittings and the cords were left to splice in the boxes.


Now what I did is I just pulled enough cord through the boxes and out through the nipples and from here I would like to loop up into my control cabinet.My control cabinet is out side the boundry mounted to the station which is by the way vented.I could put seals on the exit conduits from the station,but the boxes are plastic and the strain fittings were not explosion proof.This is my whole problem area,the damn boxes.

This manufacture normally cuts a channel into the lid and the cords are brought up and terminated into a splice box above the station.This is a normal install with the C1D1 boundry only in the station.I think what I want to do is the same thing,except im passing through those boxes.

Again I didnt design it,it's what I got to deal with.

 

[Smart $]

In short, I believe what the others are saying is, how is the box in particular, but not limited thereto, in compliance with the following:

501.10 Wiring Methods. Wiring methods shall comply
with 501.10(A) or (B).
(A) Class I, Division 1.
…
(3) Boxes and Fittings. All boxes and fittings shall be
approved for Class I, Division 1.

Question: Is there enough exposed threads of the embedded 1.5" in the box (less lock nut or such) to adequately screw on a fitting or condulet? (The number of full threads stuck in my head at present is 5)

 

[Al Pike]

In short, I believe what the others are saying is, how is the box in particular, but not limited thereto, in compliance with the following:

​

Question: Is there enough exposed threads of the embedded 1.5" in the box (less lock nut or such) to adequately screw on a fitting or condulet? (The number of full threads stuck in my head at present is 5)

Yes the condiuts stick out of the lid and I can attach a seal at this point.The one-line spec was for a nema 4x box,so I believe the manufacture should have caught it and the Engineer never should have approved the shops.No matter what the box was wrong from the get go.
Now back to a typical as built,where is the problem if a chase was cut into the lid and the cords were brought out and terminated in a panel above the station.No conduits just cords laying in the chase.I would think that its not in the C1D1 boundry and the design would not require any type of seals.Ive seen it and installed it this way.

 

[Smart $]

Yes the condiuts stick out of the lid and I can attach a seal at this point.The one-line spec was for a nema 4x box,so I believe the manufacture should have caught it and the Engineer never should have approved the shops.No matter what the box was wrong from the get go.
Now back to a typical as built,where is the problem if a chase was cut into the lid and the cords were brought out and terminated in a panel above the station.No conduits just cords laying in the chase.I would think that its not in the C1D1 boundry and the design would not require any type of seals.Ive seen it and installed it this way.

If you use the box and embedded conduit as a chase (i.e. for protection, routing only and not as a raceway) there is no problem, so long as the cord re-emerges and uses a C1D1 listed cord connector with seal where it enters a box or enclosure. Refer to 501.140 for the criteria

However, you have a problem with the box if the embedded conduits are continued on to the enclosure. It can be done if you eliminate the box from being a "wiring method box". By that I mean to extend the raceway system by adding a fitting where the conduit enters the box. Upon extending the raceway, you would have to make a transition to provide for the C1D1 listed cord connector. Perhaps install an XP box within the 4X box???

As an aside, it is entirely possible to have a NEMA 4X box that is also listed for C1D1 use. However, this is likely not your case since you mentioned the embedded 4X box is plastic :roll:

 

[rbalex]

Roughly, I believe this is what you're describing:

You're also telling us, you believe that this is analogus to a more common installation, which uses a chase rather than the box. In that case, how are the cables routed from inside the Division 1 location to the chase?

I confess I'm not familiar with either one.

 

[Al Pike]

Roughly, I believe this is what you're describing:

You're also telling us, you believe that this is analogus to a more common installation, which uses a chase rather than the box. In that case, how are the cables routed from inside the Division 1 location to the chase?

There is a horizontial saw cut about 3'' deep wrapped three side's in stainless with a open grate on it.The cords are tied to the pump rails and brought up through the trough and into the control panel with strain relief connectors or meltric decontactor plugs.

 

[Al Pike]

If you use the box and embedded conduit as a chase (i.e. for protection, routing only and not as a raceway) there is no problem, so long as the cord re-emerges and uses a C1D1 listed cord connector with seal where it enters a box or enclosure. Refer to 501.140 for the criteria

Do I need the seal on the end of my conduit where the cords exit? Im thinking yes,even though the box and lid is plastic.

However, you have a problem with the box if the embedded conduits are continued on to the enclosure. It can be done if you eliminate the box from being a "wiring method box". By that I mean to extend the raceway system by adding a fitting where the conduit enters the box. Upon extending the raceway, you would have to make a transition to provide for the C1D1 listed cord connector. Perhaps install an XP box within the 4X box???

I've thought about exproof LB with a seal inside the station,but I'm not suggesting anything until I meet with the inspector.

 

[rbalex]

Roughly, I believe this is what you're describing:

You're also telling us, you believe that this is analogus to a more common installation, which uses a chase rather than the box. In that case, how are the cables routed from inside the Division 1 location to the chase?

There is a horizontial saw cut about 3'' deep wrapped three side's in stainless with a open grate on it.The cords are tied to the pump rails and brought up through the trough and into the control panel with strain relief connectors or meltric decontactor plugs.

Getting back to the question on the sketch: Where is the Division 1 boundary and how was it determined?

 

[Smart $]

Do I need the seal on the end of my conduit where the cords exit? Im thinking yes,even though the box and lid is plastic.

Need more info. Mostly, ...

Getting back to the question on the sketch: Where is the Division 1 boundary and how was it determined?

*************

There is a horizontial saw cut about 3'' deep wrapped three side's in stainless with a open grate on it.The cords are tied to the pump rails and brought up through the trough and into the control panel with strain relief connectors or meltric decontactor plugs.

In this scenario, are there any type of "strain relief" connectors where the cord transitions from inside the pumping station to inside the trough. If not, describe how transition is accomplished. Also, please describe these "strain relief" connectors that you refer to, or better yet furnish a make and model number.

Additionally, because we truly do need specifics, is what you are calling cord in fact cord, or cable? Perhaps provide data printed on the jacket. ...and yes it makes a difference, but mostly in required connector and sealing.

 

[Al Pike]

Getting back to the question on the sketch: Where is the Division 1 boundary and how was it determined?

Spec: the station wet well is classified C1D1 groupD,everything in and connecting too shall be rated and meet the requirements of.

This is where I have a problem with the box being flush with the inside roof of the lid. The spec quotes: install a nema 4x box embeded in the lid.I think the manufacturer of the station installed the wrong box and the engineer never should have approved the shops.

 

[Al Pike]

Need more info. Mostly, ...

​

*************

In this scenario, are there any type of "strain relief" connectors where the cord transitions from inside the pumping station to inside the trough. If not, describe how transition is accomplished. Also, please describe these "strain relief" connectors that you refer to, or better yet furnish a make and model number.

Simply put, the pump cords and float cords are laying in the trough.

Additionally, because we truly do need specifics, is what you are calling cord in fact cord, or cable? Perhaps provide data printed on the jacket. ...and yes it makes a difference, but mostly in required connector and sealing.

Yes they are cords. SOOW

 

[Al Pike]

Pictures

Pictures

I found a install I completed and the one in question with the control mounted only.I wish I had the boxes.
Pump pic 2,3 are the one with the trough.It is in front of the junction box and the cords came up to the plugs.That box has distribution blocks inside to terminate the cords to.The control panel is behind it.

Pump pic 1,is the one in question.You can see the exit conduit's,but I'll have to get a picture of the lid boxes.They are pretty much like Rbalex picture.

 

[Smart $]

Spec: the station wet well is classified C1D1 groupD,everything in and connecting too shall be rated and meet the requirements of.

Hmmm.... still leaves some doubt as to exactly where the C1D1 boundary is located.

If I had to go with nothing more than what you wrote, I would have to say the outer surface of the well is the boundary, making the box, used as is, a violation.

 

[rbalex]

I found a install I completed and the one in question with the control mounted only.I wish I had the boxes.
Pump pic 2,3 are the one with the trough.It is in front of the junction box and the cords came up to the plugs.That box has distribution blocks inside to terminate the cords to.The control panel is behind it.

Pump pic 1,is the one in question.You can see the exit conduit's,but I'll have to get a picture of the lid boxes.They are pretty much like Rbalex picture.

The photos help considerably. I still don’t know what the electrical area classification boundaries are consdered to be – but I believe I now know what they should be and there are more issues than a few seals; e.g., the vent alone has a minimum 5’, Class I radius of effect from the point of exhaust.

Do you know what standard, if any, was used to as the basis for the electrical area classification? Was it any of the documents mentioned in NEC 500.4 (B)? While the list is not entirely exclusive nor exhaustive, I believe documenting the Standard used as the basis to classify a location is part of the “proper documentation” required in Section 500.4 (A). It would be if I were the AHJ. As someone "... authorized to design, install, inspect, maintain, or operate electrical equipment at the location," you still have a right to whatever documentation is available.

If someone says a location was classified solely per the NEC, and doesn’t specifically mention which Article (511 through 516) was used in the same breath, they have clearly established a severe ignorance of the proper process of electrical area classification.