ECN Forum Forums Photo Discussion Forums Photos for General Discussion Rooftop Antenna

Iwire's got it!

The maintenance electrician caught me taking this picture, and the conversation went nearly verbatim with HotLine1's description above, even to the weathered copper that was "just put in".

(The weights on the base are just machinery parts, non-automotive)

The guy asked me if I had a proper ground clamp on my truck. Of course he'd replace it as soon as he can get to a store.

I went to a copy machine in the plant and made him a copy of 810.21 instead.

There are still very obvious violations unrelated to the antenna in this pic.
Any takers?

[This message has been edited by electure (edited 07-30-2005).]

I'll bite:

First off, that's a solid piece of EMT which goes into the cover of the W/P box;

No supports visible for the EMT or the box;

Sealtite to the mushroom fan not supported.

edit: Oh, yeah, and that sealtite looks to be more than 6 feet long, too.

As a side note, the nice coils in the ground wire to the antenna will make a great choke coil to any lightning currents.

[This message has been edited by mxslick (edited 07-30-2005).]

Shouldn't there be a "within sight" disconnect for that exhaust fan?

Mike (mamills)

Take the cover off the mushroom fan and there is a disconnect switch.

Yup,
The box is not properly supported. 314.23
The EMT is not securely fastened in place within 3' of the box. 358.30(A)
The Liquidtight Flex is not secured properly. 350.30 (A)

You can't tell from the picture, but the EMT runs into the back of the box, and that's Liquidtight Flexible Metal Conduit. LFMC isn't subject to the 6' length limitation that LTNC is.
The disconnect for the mushroom fan is right where DMattox says.

The one that I seem to find all the time is
this bit with the 90° connectors:



300.18(A) Complete Runs.
It seems to go largely ignored
Is it common elsewhere?

edited because I goofed up

[This message has been edited by electure (edited 08-02-2005).]

I don't think you can apply the "complete runs" rule to a "flex" 90.

What I see most on rooftops is absent from all these pics....the flex coming loose, or being broken. Whether this is because of folks tripping over it, or just general weathering, I don't know.

I do try to run my stuff in a manner that conforms more closely to the contours of the roof, and the equipment.
To avois punching holes in the roof, I attach my stuff to wood "sleepers" (short pieces of 2 x 4) that are in turn attached to the roof with roofing cement.

300.18. Raceway Installations
(A) Complete Runs. Raceways, other than busways or exposed raceways having hinged or removable covers, shall be installed complete between outlet, junction, or splicing points prior to the installation of conductors. Where required to facilitate the installation of utilization equipment, the raceway shall be permitted to be initially installed without a terminating connection at the equipment. Prewired raceway assemblies shall be permitted only where specifically permitted in this Code for the applicable wiring method.

Why wouldn't it apply?

I don't think you can apply it, because the radius of a 90 degree fitting is a lot tighter than that allowed for any raceway material (including the various forms of "flex"), and approximates the bend inside an LB or pulling el.
I'm not even sure it's possible to run a fish through the smaller sizes!

No, you can't run a fishtape or pull wire through it. That's the point!

We do our wiring to comply with the Code. We don't apply the Code to comply with our wiring preferences.

LBs, Capped ells, Pull elbows, have a removeable cover. A 90° sealtite fitting is more like a telephone elbow, or a plumbing elbow. How about a 100' of EMT or rigid run to a telephone ell (bushed elbow), and another 100' slid over the end of the conductors after the 90? Same thing IMO
Is a fitting part of the raceway? I believe it is.

BTW, I'll bet you can take 9 out of 10 Sealtite fittings apart by hand without the use of tools. It's rare to find the gland nut tight.
Another nasty habit: For installers to think that because they've got a straight piece of conduit coming through the roof, the other 360° degrees of bend below the roof line don't count and they're starting anew.

If you can find something that excludes this fitting, I'll eat my hat....again....some more

I think that 300.18 is clear.



[This message has been edited by electure (edited 08-03-2005).]

In the left-hand picture just above, the WP box is oriented with the receptacles facing straight upwards. I don't see that NEC has anything to say about it, but would an inspector allow it? Is it good practice?