Fri Picture-22 #12 wires in a 3/4" RMC

[SeanD]

Mechanical advantage. Try to figure a way to use a lever to help pull the wire.

 

[chevyx92]

I come up with max of 16.

If pulled hard enough they may be stretched and are now 14 AWG:grin:

You're correct 16 is the max, not 14.

 

[mivey]

I've tried, but I don't see 22 wires in that pic. Are you sure you counted correctly ?

Nakulak, best I can count is 17.

I don't know Tom personally but I'm going to go out on a limb here and say he can count. BTW, I saw 22. :grin:

 

[KentAT]

You're correct 16 is the max, not 14.

Hmmm...I come up with a max of 8.

 

[KentAT]

Now I'm really confused.

Using Chapter 9, Table 4 for RMC and #12 THHW, I get:
0.220 sq.in. divided by 0.0181 sq.in per conductor = 12.15, or 12 conductors.

Using Table C8 for RMC and #12 THHW, I get:
8 conductors.

Why are these numbers so different?

 

[RICK NAPIER]

nhfire77

Senior Member

Actual syrup?

These were not diners but the production facilities and the MSDS report has it falling under the IBC as a corrosive and they had to built a seperate room for storage with sensors, ventillation and a spill protected flooor design.

 

[KentAT]

Now I'm really confused.

Using Chapter 9, Table 4 for RMC and #12 THHW, I get:
0.220 sq.in. divided by 0.0181 sq.in per conductor = 12.15, or 12 conductors.

Using Table C8 for RMC and #12 THHW, I get:
8 conductors.

Why are these numbers so different?

Anybody?

(since they are different, I would use the calc. = 12 instead of the table, correct?)

 

[iwire]

The conduit fill tables are not part of the code, they are informational only so you have to go with the math.

Why the tables are not accurate I do not know, I generally use the tables as a rough guide, if it's close I do the math.

 

[KentAT]

Thanks........

 

[tom baker]

Yes they were low voltage, or actually logic ground controls - no voltage. It was a mess, none of the wires were labeled, there were 4 valve actuators, each had 11 wires that went from a large JB into a 3" conduit, plus others. When it was pulled there were 50 or so spools and a backhoe to pull it in.

 

[zappy]

The best I new of was an apartment building turned condo turned offices. When they were gutting the building for offices the electricians found 2" pipe packed so tight that when they cut at a 1' section and held it to the light no light passed threw. One of the electricians knew someone who worked on the conversion from apt to condo and asked how did they pack it so tight for a pipe that went from the basement to the 4th floor. He was told they used pulleys tied to a truck hitch. Then theey tested the wires out and any ones shorted to ground became neutrals.

I'm speechless!

 

[zappy]

The conduit fill tables are not part of the code, they are informational only so you have to go with the math.

Why the tables are not accurate I do not know, I generally use the tables as a rough guide, if it's close I do the math.

What about annex C? Is it correct?

 

[Volta]

Actually close nipples have a fill limit of 60%. Chapter 9 Notes to tables #4. According to the wording this would not apply to a chase nipple.

Why not?

What about annex C? Is it correct?

Mostly . . . not 100% though.