Sunday, February 20, 2011

Best of intentions not thought thru


When ITE Corp came out in the late 50's with the Pushmatic or sometimes called Bull dog Breakers it was hailed as an excellent design for a breaker system in a home or business
Instead of the typical breaker which plugged into the Panel Buss bar that could become loose and dislodge resulting in electrical fires the new design was made that the Breakers would bolt directly to the panel Buss bar making for solid tight connections. In realty It was a really good breaker
design unfortunately in the real world though it was also a hazard .
Too many Electricians when installing the breakers into the panel Buss bar did not properly line up the screws which resulted in stripped or cocked screws and ended up causing hot spots in panels and fires out of all the 100's of these panels I have come across in my daily job 90% had at least 1 or more badly installed breakers do to neglect by the installing electrician not making sure the screws were installed fully into the buss bar.
As a result the breakers and panels are no longer made and the manufacturer has gone back to a traditional design.

The next Product which again started out with the best of intentions but is now no longer produced are Breaker and fuse panels known as Split main Panels .
the panel had a main breaker known as a Lighting main usually no more than 60 amps which controlled only the lower end of the panel .
the lower amp main was designed to trip before damage to the panel would result from a run away short circuit . again an excellent idea but also extremely dangerous as the top 4-8 breakers in the panel had no main to protect them so the buss bar was always hot main thrown on or off
the upper breakers were to only be 2 pole high amp breakers 30 amps and up such as for Dryer
, range etc. but all to often the home owner see an open slot sticks a single breaker in to this slot and not realizing the buss bar is always hot ended up causing an explosion when his screwdriver mad contact with the bus bar. I have seen many rookie electricians make the same mistake with these panels myself included .luckily I escaped injury and did not cause serious damage. to the equipment .

Another product being slowly phased out by Utility company’s is Lead Jacketed cables for under ground wiring. Although the lead sheath made for excellent underground cable it was usually under a rubber jacket and not apparent from other cables other than its stiffness when you tried to bend it. My father related to me when he was on a job with another electrician on an underground service they came across this particular cable and the electrician working with my dad accidentally cut into this cable with a cutter thinking it was normal cable which resulted in burns to the electrician after he caused a massive short cicuit as the cable was a service feeder and had no fusing .they ended up knocking out the power to a whole block after the fuse at the power transformer finally opened.

Another electrical system I would like to see taken off of the market is known as a Series rated
Breaker system. in which all the breakers in a electrical system have the same Short circuit rating IE 10,000 amps interrupt. But a short circuit that can produce more than 10,000 amps is
The danger behind these systems one breaker being damaged by an out of control short circuit can knock out an entire store or buildings breaker system creating a building wide black out.
as there is no higher rated breakers to stop the short circuit.
Series rated Breakers are typically found in residences but in commercial buildings typically the main beakers are 2-3 times short circuit interrupt rated higher than the individual branch breakers
which provide power and lighting on the floor in a system designed to prevent blackouts you will find the individual branch breakers rated 10,000 amps short circuit , the sub main breakers rated at 25,000+ and main breakers rated 100,000 amps +, this prevents one run away short from getting past the sub main breaker thereby only knocking power off in the sub main panel on that floor or area not the whole building.
However electrical designers can use Series rated systems were careful electrical practice is used but again in the real world it is not. All too often this is why one simple short circuit can knock out an entire complex due to negligence o n the part of electricians not following the series systems wiring precautions.

As you can see Electrical wiring and design gets extremely complicated and the national electrical code is the most complex code developed. This is why only trained individuals should do this work. Electrical work is not for amateurs. But then again as fireman we see this every time we have to respond to an electrical condition or fire.

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