Not the best picture in the world, so I'm not sure I see your point.
You were expecting fiberglass ladders?
At nearly double the cost, I think not.
- Chris
I'm not getting the point, care to elaborate ?
I am sure OSHA would love seeing them work off them on a job site
some where.
aluminum ladders are for painters and residential use. where there's
no possibility of not contacting electrical wires .
I know for a fact I am one of the few alarm contractors in my area who
has all the required safety equipment for climbing including 4 point
harness etc.
I do not allow aluminum ladders on my truck or on any job site where I am
the prime contractor. Its been tempting over the years to get on a
multifold ladder of some kind, but the fiberglass ones are very heavy when
you can even find one, and the weight rating is usually too low for me.
Sounds slightly anal-retentive to me, I don't have a problem with
aluminum ladders and never felt the need for a 4 point harness. Then
again my jobs were mostly residential.
Some generals I have worked for prohibited aluminum ladders also, and I have
done a lot of commercial and some industrial. Never was a problem for me.
I refuse to allow aluminum ladders.
I have no problem with someone deciding not to use them and depending
on the work they do I also have no problem with someone who does use
them
Until you reach through a drop ceiling and see the floating ends of the grid
arcing to the angle on the wall. LOL. About then you are really glad you
are standing on a fiberglass ladder.
> Its been tempting over the years to get on a
>multifold ladder of some kind, but the fiberglass ones are very heavy when
>you can even find one, and the weight rating is usually too low for me.
You'll end up like this fool:
http://www.youtube.com/watch?v=6ZhMfzc9RbU
You'll be fine as long as you don't have sweaty feet ;)
All my ladders are fiberglass except for the one I use most, my super
light 6 foot aluminum stepladder, It's great for small residential
where you move the ladder 2000 times a day.
"John Smith" <aliasJ...@nokidding.com> wrote in message
news:UWZVm.75284$We2....@newsfe09.iad...
Of course they could be wearing Faraday suits on the job sites.
--
YOP...
I would be more concerned with the ladders the installers use, I don't
really think it matters what the office people use
Nah, just aluminum foil hard hat liners.
That's an authorized dealer logo on the vehicle
I have not owned an aluminum ladder in atleast 15 years.
Think I could get one of those?
Seriously though, since we are talking about aluminum ladders, and more
to the point - the reason for not using them, ie: electricity; I have a
a question about something that came up on an oil field consulting job I
was just on (trust me, if you were as ADD as I am this logic would make
perfect sense).
I'm no electrician (and I can't afford to stay at a Holiday Inn Express)
and don't generally like to play around with big-boy voltages but if I'm
not mistaken, ground is ground the world around...
Many many years ago is used to work as a mud logger
(http://en.wikipedia.org/wiki/Mudlogger) and am re-training so I can
pick up some cash here and there. It's good money but the jobs are
infrequent at best.
Anyway - I'm working out of the company man's trailer and, yesterday,
after he takes off his thick rubber boots and steps out he finds that
the trailer skin is electrically hot.
Long story short we finally found that the coffee pot had a short
somewhere that was feeding 110 back into the ground circuit. Trust me,
the loss of the coffee pot was a bigger blow than finding the 110 on the
door handle.
Oil rig electrical systems are notorious - partly due to rickety
generators (that put out 90 VAC one minute and 200 VAC the next) and
partly due to roughnecks.
Roughnecks, God bless 'em, are some of the toughest, hardest working
folks I've ever met and absolute geniouses at making just about anything
"work" via bubble gum and band-aids but, as creative as they are, if
pressed to do thing the "proper way" they would be clueless.
Surprisingly enough - these fixes almost never raise the eyebrows of
OSHA inspectors despite how scary it looks.
As a result, some of the folks who bring work trailers to the locations
will put out their own ground stakes as an added precaution. The
company man has taken (what he considers to be) the added measure of
removing the ground from the incoming power cord so he has only one
ground on his systems.
His trailer is about 100ft from the rig on frozen, sandy ground and I
suspect the poor ground reference back to the main panel is why we
didn't trip the breaker in the generator house when the short occurred.
Does anyone know if having both grounds present is a problem? I can't
remember what the rules (or more important - the why's) about proximity
regarding two ground stakes in in an electrical system.
He swears by the separate ground stake for the trailer so that's not
going away, but I think I should try and talk him into reconnecting the
rig ground as well.
He's a reasonable guy and if it's the right thing to do he'll go along.
I just want to be sure it's the right thing.
Also - the trailer's real sensitive equipment (gas monitors and such)
are protected by redundant UPS's and a rheostat.
Any help? I got to go back out tonight or tomorrow...
A better description of mud logging with illustrations of the log
created: http://en.wikipedia.org/wiki/Mud_logging
Obviously code varies, but:
Yes, ground is ground the world around, but quality of ground is not
the same the world around. Different types of ground conditions can
play a role. I knew of guys who tested ground rods by trying to trip a
15 amp breaker by shorting it to the ground rod. While not the proper
way to do things it does illustrate a point. It is likely the
resistance between these "additional" trailer grounds and the
generator grounds is too high, so they are not equal to a ground
supplied at the generator. It's likely if you were to touch a live
wire from the generator to one of these "additional ground rods it
would spark but not trip the breaker. They are likely causing the
problem by removing the grounding conductor and supplying their own
ground. Though the grounding at the generator may be insufficient too.
Everything conductive on the trailer should be bonded back to the
ground bus. Also the neutral should be separated from the ground and
any appliances or equipment with bonding straps between the ground and
neutral should have them removed.
The trailer itself should get ground from the supply cord, it
shouldn't be grounded itself. I would suspect poor grounding at the
power generating station or undersized grounding conductor.
That's the thing - he has disconnected the ground from the generator and
is grounding the trailer independently.
So you are saying he should lose the trailer ground and reconnect the
generator ground. What if, rather than connecting the ground stake to
the ground bus - he connects it to the trailer frame?
Gas & oil rigs attract lightening during those rare occasions that
conditions are right, and structures around them get a lot of big surges.
Heh, yeah... good one. ;-)
>Does anyone know if having both grounds present is a problem? I can't
>remember what the rules (or more important - the why's) about proximity
>regarding two ground stakes in in an electrical system.
I'm no electrician, but I would say it's definetely a problem. The
ground reference is not going to be equal on both sides. Despite what
common sense dictates that "ground is ground", is not entirely true.
>He swears by the separate ground stake for the trailer so that's not
>going away, but I think I should try and talk him into reconnecting the
>rig ground as well.
I would think about putting a subpanel right at the trailer, bonded to
the trailer and a hefty rod depending on the soil conditions. If it
is ice, it's not a ground. How thick is the ice?
And like you said, bond the two grounds from the source and the
trailer so they are equal.
This is just an opinion of what I think is a safer way. Don't take my
word as gospel by any means! I highly suggest you post the question
in: news://alt.engineering.electrical They have a really qualified
group of guys there to better answer the question.
Trailers are supposed to have all non-electrical metal already bonded
to the ground bus, frame, siding, everything, and its all tested
before it leaves the factory. That is assuming these are trailers made
in North America and not Botswana or something. You should already
have continuity from the frame to the ground bus. As far as lightning,
any lightning arrest system should be independent of the trailers
ground system.
Even in parks where there are sub-panels right at the trailer the
ground comes from the main distribution panel, there would not be
another ground rod at the sub-panel.
I would still suspect the grounding back at the generator. In poor
soil conditions it can take several 10 foot copper ground rods to do
what 1- 8' galvanized rod would do in good soil.
Heh - heh - heh
I forget - not everyone has worked in the oil field.
These guys do things as cheaply as possible these days.
This is a 8x12 enclosed "Haulmark" trailer with a double back door (not
used) and a regular door on the side. All the wiring has been
retro-fitted...
Folks think that oil field consultants make big money - and the amount
they make per well IS real good - but they may only get 6 - 10 holes a
year. Ever since the big boys got out of the drilling business in the
US it's all little guys who have to scrape up investors for every hole.
More jobs fall through than actually spud in. Often you don't get
word yeah or nay until a day or two before they are to move the rig. If
you are on the line for one job, you can't accept another 'cause if they
BOTH work out you are screwed. The oil patch is a good ol' boys network
and if you back out of a job and they have to waste rig time finding a
replacement - good luck getting another phone call...
Now, back in the 80's when I did this before, you could rely on work all
year long 'cause the biggies planned their stuff way in advance and
everything went off as scheduled.
I'll try and talk him out of the independent trailer ground or, at least
use his rod for JUST the trailer frame (it looks like the panel is
grounded to teh trailer only be the screws holding it on). I'm pretty
sure I can convince him that he HAS to reconnect the ground from the
generator.
I have always been amazed at what they get away with - UNTIL someone
gets killed (for whatever reason) and then, all of a sudden, OSHA has
eyes again...
I would try to get them to bond the frame to the body and the body to
the panel ground, that should at least prevent the type of
electrocution you described earlier. Having a ground rod at the
trailer could cause everything else to try to ground through your
trailer