Rooftop Antenna - ECN Electrical Forums

Wasn't this installer resourceful?

[Linked Image]

Did he connect the ground to PVC?

No, but he tried.
Alan

It's not PVC, it's EMT.

What would it take to correct this? There's a dish receiver on the top of the "mast"

I was going to offer all sorts of helpful advice- but considering the obvious lack of skill, tools, and materials, I suppose it's best he didn't make any holes in the roof.

[This message has been edited by renosteinke (edited 07-29-2005).]

Well, that's even dumber!!! Not only not grounded (earthed), but a possible hot (live)mast! What a dope!
Sadly, you can't educate pork.
Alan

Comcast used the PVC grounding once, I sent them a violation

"But sir (Mr. Inspector), I put that on as a 'temporary' ground 'till I get to the store and buy a pipe clamp. (Notice what appears to be weathering on the stripped cu)

Heck, cable guys and telco do some of crazy "grounds" to. SEU/SER/PVC, meter hub mounting screws, any thing you can imagine.

John

Is that a brake disc being used as weight?

Folks electure told us it is EMT.

It is not PVC.

It still is a violation.

Quote

The grounding conductor shall be connected as follows:

(1)To the nearest accessible location on the following:

a.The building or structure grounding electrode system as covered in 250.50

b.The grounded interior metal water piping systems, within 1.52 m (5 ft) from its point of entrance to the building, as covered in 250.52

c.The power service accessible means external to the building, as covered in 250.94

d.The metallic power service raceway

e.The service equipment enclosure, or

f.The grounding electrode conductor or the grounding electrode conductor metal enclosures; or

(2)If the building or structure served has no grounding means, as described in 810.21

(F)(1), to any one of the individual electrodes described in 250.52; or

(3)If the building or structure served has no grounding means, as described in 810.21(F)(1) or (F)(2), to an effectively grounded metal structure or to any of the individual electrodes described in 250.52.

Bob

Iwire's got it! [Linked Image]

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:

[Linked Image]

300.18(A) Complete Runs.
It seems to go largely ignored [Linked Image]

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.

Quote

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

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 [Linked Image]

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?

Electure,
My first thought when looking at that stand was, how well will the dish stay in place with a good gust of wind behind it?.
What sized dish is on the end of this mast and how high is it?.
Other side of the coin, how exactly is that Grounding wire attached to the rusty steel stand?.
Wouldn't grounding the mast to the length of EMT that carries the fan wires introduce electrical interference into the Sat installation?.
Just my opinion, but I don't reckon there's been any planning put into this job. [Linked Image]

Who wired this place, Uncle Billy Bob from Oklahoma??
(Not to impune OK, I loved it there).

Creative, my sympathies to anyone who doesn't see that wire and ends up tripping over it.