|ITE split main panel where red label is located these breakers mnust be 30 or more amps and have no main protection|
Wednesday, February 22, 2012
Split main breaker panels they hurt rookie electricians
Split Main Electrical Panels and badly Designed Breakers
An accident waiting to happen
In your home or business
Before they where banned in early 1970’s
The Split Main Electrical Panels where very popular in all electric homes.
The original intent of the design was to prevent accidental overloads and tripping out of the main breaker
and or Main Fuse and losing all power.
When an Air conditioner, electric dryer and electric stove might all be turned on at once.
But the panels came with a very big danger. In order to accomplish this feat the heavy 230 volt 2 pole breakers or 60 amp side fuse pulls where attached directly to the main panel bus and there was no main breaker or fuse protection.
So to the unsuspecting individual who would work in these panels when they turned off the main Lighting breaker or fuse they often times where not aware the 230 volt breaker or fuses where still sending power thru them.
You where powered directly out to the street.
The part of panel which was not protected by the main where only suppose to have 230 volt 2 pole breakers rated 30 amps or higher but often single pole 15-20’s where put in the spot causing an even bigger danger to an unsuspecting home owner who might try working on the panel.
To make the situation even more dangerous is the fact many of these panels have in them
Federal Pacific Breakers which have seen several recalls due to failure to trip on an overload.
But Federal pacific is not the only breakers with bad history’s.
Ask any experienced electrician who does trouble shooting on a regular basis and the Names
Zinsco and Murray will often come into the conversation.
Older Murray panels have a very badly designed main breaker which instead of being bolted to the panels main bus bar is just stabbed on like a regular breaker and only a small amount of metal makes contact to the bus bar and over time will heat and loosen with heavy use.
The Zinsco panel breakers like the Federal pacific breakers will not trip on overload and recently from the field I am getting a lot of reports that GE breakers manufactured in last few years are starting to exhibit this same problem.
A different type of problem plagues the older ITE / Bull Dog Pushmatic Panels.
The panels which are no longer made where actually very well designed with each breaker having to be bolted down on the bus bar instead of just stabbed in but the problem developed when electricians failed to properly install the breakers screw to the bus bar and many where stripped or cocked into place not making full contact to the bus bar
Now add in the dangers of aluminum romex and you have the makings for a fire.
Often times problems with electrical equipment happens because of bad install by the electricians who did the work or wrong panel was used for a job where a commercial panel board instead of a breaker box should have been used .But too many times it is badly designed equipment. Here is an excellent video on You Tube showing one as well as n inspectors blog with pictures
I work regularly with the CPSC The Consumer Products safety Commission in the reporting of bad products in the field ,but the problem is when electricians encounter problems they correct them and never make note of them or report them.
Posted by Nick Markowitz Jr. at 9:12 PM