cobb power box buyer beware

[steve g]

my cobb power box made it in the other day. I have looked at it very closely and the idea and overall design of it is good. the plugs on the front have the tabs removed so they are actually able to run as a seperate circuit on each leg, the two legs split to a dual 20 amp breaker on each leg, however the cord is only rated at 30 amps off each leg, plus your extension cords are only rated to 15 amps, so with that said you have to stay at or below 60 amps of 120 power, even though there is more power at the breaker if you are hooked up to the range outlet, so to be safe I plan to load each plug to about 13.5 amps or less just so I have a margin to work with. each recepticale is a seperate breaker that is tied together.

now for the bad, the cuts on the box look pretty ghetto, the sticker lettering was put on in a hurry. the bottom metal plate looks kinda hacked up. the wires were not all tight, and worse yet is the box was wired WRONG. fortunately I showed the box to some guys at the electrical supply store, they thought the box was pretty cool and looked over it very closely. one of the guys noticed that on leg had both the neutral ie white wire and the red wire going to the same side, so this caused one side of the outlets to actually have the full 220 volts of power. I thought it was odd that when I first tested the box with a small lamp one side lit up the bulb like a 100 watt bulb, the other side just lit it up normal. thank god I showed this to the guys at the electrical store. they told me it could have caused something like a vacuum to catch fire and at least could have ruined one my 2k dehumidifiers.

 

[Jim Martin]

wow.......a neutral and a hot both going to the same side....and the thing did not short out when you plugged it in.....and it over charged a small bulb and lit it up like a 100 watt with out blowing it all to hell......you must be living right.......

I know that the outlets weren't a GFI.....you can not isolate them....(split them)....were the breakers GFI rated......

 

[Mikey P]

What did Larry have to say ?

 

[sweendogg]

It it was one of the floresence lamp light bulbs, its probably what saved your hide.

 

[steve g]

it was only plugged in for like 2 seconds at a time, I tested all 4 outlets and they are all running 120 volts now. the last thing I am going to do is give it a trail run at my house fully loaded down to see how it does. let it run a couple hours, make sure nothing is overheating etc. one of the guys that looked at was a master electrician and said everything looks good now. I am still a little chicken to light this baby up in a customers house I must admit.

 

[dealtimeman]

:shock: :shock: you are very fortunate that you got that taken care of before you placed in service. yikes :shock:

 

[Desk Jockey]

I am still a little chicken to light this baby up in a customers house I must admit.

Nothing against Larry or anyone else that builds these type of units but I'd buy a yellow spider box from the big guys. I'm all for saving money but when there is risk involved I'd rather spend it and sleep at night.

 

[Jim Martin]

 

[Desk Jockey]

Jim
I had our electrician look at our spider box a few years ago to make us a pigtail for a range and he wasn't too thrilled with it.

Do you have reservations about using spider boxes in homes?

 

[steve g]

I have thought alot about it, if you look at how this spider box is done its really not any different if you think about it than the way the house current works and how the power is setup in the house. you split the power back out of the legs and bring it back down to 120, you have breakers that protect it, you also actually have the breaker at the panel as a further protection. however with that said IMO you could get in trouble with the cobb box, if you are dumbass, anyone that hooks one of these up on the job should know what the amp draw is on each piece of equipment and also understand extension cords are rated at 15 amps, to be safe and to make sure the breakers don't trip I personally plan to stay below 13.5 amps on each cord. the way one could get in trouble is using the box on a twin 40 amp range plug, this would allow you to run a full 40 amps off each leg, but the problem with that is the cord running to the box, is rated at 30 amps per leg, your cords are only rated at 15 amps, so in that situation you could overload the thing. so if you plan to use it, make sure whomever is doing it knows how it works and is smart about it.

 

[Jim Martin]

Jim
I had our electrician look at our spider box a few years ago to make us a pigtail for a range and he wasn't too thrilled with it.

Do you have reservations about using spider boxes in homes?

All a distribution box is...is the electrical panel box that hangs on the side of your house......you are taking a certain amount of amperage off of that box and breaking it down into smaller amps and sending it to where ever....There are certain things that you should not do and just because someone gets away with it does not make it safe.....A good example is Cobb cutting the bridge on the outlet and feeding each one with its own breaker......so in theory you are sending 40 amps over to 1 ....15 or 20 amp outlet......true....it is broken apart but that was not what that bridge was designed for......so .....we got away with it and to my knowledge there is no code that will tell me that you can't........Just every electrician out there that has any type of common since will tell you that you are going to have a melt down sooner or later......and when some stupid S.O.B.burns down a house because of it...then it will be a code.....that's the way it works.......

Just like everything else out there most people will try to cut corners and make things as cheap as the can and then charge you a arm and a leg for it.......If done correct and if the right materials are use.....a good distribution box will last years ...trouble free and you will be able to run just about anything you want off of it that is rated for the amount of amperage that the breaker in the box will allow..........But they will cost....Outlets like the one I pictured above....GFI breakers...a weather tight box...weather tight fittings.....proper cord caps.....but most important.......the proper type wire that will feed the box......and plain common electrical since........

 

[dgardner]

Steve, do yourself a favor and get yourself one of these:

It will alert you to a miswired receptacle, in your case - a hot conductor wired to the neutral side. Less than 10 bucks at any of the home centers.

 

[Larry Cobb]

Steve;

I am concerned and confused about your post.

Each outlet is split wired for 120 Volts AC and protected by a 20 amp U.L. rated circuit breaker.
The standard box you purchased is designed for 30 amps 230 VAC input.

If you need 50 amp input capability, we can also provide a distribution box for that.

it was only plugged in for like 2 seconds at a time, I tested all 4 outlets and they are all running 120 volts now. the last thing I am going to do is give it a trail run at my house fully loaded down to see how it does. let it run a couple hours, make sure nothing is overheating etc. one of the guys that looked at was a master electrician and said everything looks good now.

Was any rewiring done before the master electrician looked at the box??

We have lots of these boxes working under tough conditions without any problems.

Larry

Jim;

Thanks for your concern.

The box wiring design was done correctly. The outlets are designed to be fed by separate legs of 220 voltage.
Most importantly, they are protected by 10,000 amp interrupting capable U.L. breakers, as specified by the electrical code.

 

[Jim Martin]

Jim;

Thanks for your concern.

The box wiring design was done correctly. The outlets are designed to be fed by separate legs of 220 voltage.
Most importantly, they are protected by 10,000 amp interrupting capable U.L. breakers, as specified by the electrical code.

Its all good Larry.........as I stated above..I do not know of any code that tells me that it can't be done.....Its just not good electrical sense........

 

[steve g]

larry, actually it was the electrician that noticed the problem, rewiring per say was merely switching the white and black wires, so the neutral ie white wire was actually going to the neutral on both outlets. I have no doubt these boxes are used in ruff conditions. I also understand exactly how much power I can safely use from it. up to 15 amps per outlet of 120 power, this box is no different than how a house breaker box works. The electrician said I should have no problems out of it. but IMO I would double check to make sure the boxes are wired correctly as mine did have both neutral and hot going to one of the legs. which meant it was 220 volts.

 

[Jim Martin]

larry, actually it was the electrician that noticed the problem, rewiring per say was merely switching the white and black wires, so the neutral ie white wire was actually going to the neutral on both outlets. I have no doubt these boxes are used in ruff conditions. I also understand exactly how much power I can safely use from it. up to 15 amps per outlet of 120 power, this box is no different than how a house breaker box works. The electrician said I should have no problems out of it. but IMO I would double check to make sure the boxes are wired correctly as mine did have both neutral and hot going to one of the legs. which meant it was 220 volts.

wish you would of taken a picture of that..........unless they used the white( neutral wire)..as a carrier of 120 volts that would of been the only way to get the 220....if the white was used how it was meant to be then the black and the white would of only given you 120......if the black and the white were on the same leg then you should of gotten on big direct short.......I am really interested in seeing the inside of this box.......could you take a picture of it for me please..........

 

[Larry Cobb]

Jim;

I'll send you some photos of the interior of the box.

I have them at work.

Here is a photo of the fiberglass exterior:
Notice the commercial 20 amp receptacles (same plug style as your photo)

Larry

 

[Jim Martin]

Jim;

I'll send you some photos of the interior of the box.

I have them at work.

Larry

cool thanks....

 

[dgardner]

wish you would of taken a picture of that..........unless they used the white( neutral wire)..as a carrier of 120 volts that would of been the only way to get the 220....if the white was used how it was meant to be then the black and the white would of only given you 120......if the black and the white were on the same leg then you should of gotten on big direct short.......I am really interested in seeing the inside of this box.......could you take a picture of it for me please..........

Jim, remember the recepts are split - each half of the duplex is fed a different hot. So the link between the two gold screws is removed. If you, say, swap the white and black wires, picture what the result would be. You would have a black (hot) on the neutral side (common to both halves of the recep), you would have a red on one of the gold screws (that outlet now has a red and black, giving you 240v), and the other gold screw would have the white (that outlet now has a black and white, giving you 120, but with H and N reversed).

I could see it happening if the assembler were in a hurry, distracted or whatever, especially if he/she were not a qualified electrician. I recommend the manufacturer plug every single unit in and test with a recep tester like I showed in my earlier post before shipping. All you guys out there are irreplaceable!

 

[Jim Martin]

..I guess I read this part to fast.................

one of the guys noticed that on leg had both the neutral ie white wire and the red wire going to the same side,

 

[steve g]

..I guess I read this part to fast.................

one of the guys noticed that on leg had both the neutral ie white wire and the red wire going to the same side,

exactly, I should have been clear on that, the silver screws on one side of the outlet are for the neutral. these have the bridge/tab intact. the brass side ie hot, is the one with 2 different hots going to it and has the tab removed between the 2 screws, so each outlet of the pair has a separate 20 amp breaker hooked to it. I learned quite a bit more about electrical lately and to me that is good thing.

 

[floorguy]

should have taken pics to document it...

then he(we) could see if it was in fact wired wrong...then he could FIRE someones ass

 

[steve g]

everything is cool, larry called me and explained how it happened sounds like an isolated incident.