6 flicks to turn off power

[homeinspector12345]

Im a new home inspector with a quick question.

It should take 6 or less handmovements to turn off all power to home. In a panel with no main disconnect, how do you know if one of the breakers turns off power to the rest?

Thanks,

Scott

Click to Enlarge

53.45 KB

[Ben H]

In a panel with no main disconnect, how do you know if one of the breakers turns off power to the rest?

It won't. If one breaker was feeding the rest, it would be a main. Was there a main disconnect outside by the meter?

[homeinspector12345]

Thanks for your response ben. There was no main disconnect by the meter.

When I see a panel with no main disconnect it looks like all breakers would need to be flipped to turn off all power to home but I know that there are panels where there is no main disconnect and the first few breakers power the oven, dryer, AC, etc and then there is a breaker that turns off power to the breakers below it.

How can I tell if one of the breakers turns off power to the breakers below it?

I want to be able to figure out if a panel with no main disconnect complies with the NEC requirement of 6 or less handmovements to turn off all power to home.

[hausdok]

Im a new home inspector with a quick question.

It should take 6 or less handmovements to turn off all power to home. In a panel with no main disconnect, how do you know if one of the breakers turns off power to the rest?

Thanks,

Scott

Click to Enlarge

53.45 KB

You're thinking that it's a main panel. I don't think it is. It looks like a sub-panel in multi-family housing. Was this a condo or one of several units in a multiplex? All of those 4-pole 30 amp breakers are screaming electric heaters to me, which is also something I see in multiplexes or small condo flats a lot.

You have a total of five two-pole breakers in the top half of that panel; four of them are 30-amps and the other is 40-amps. In the bottom, you have two two-pole 30 amp breakers on the left bank plus a single-pole the size of which I can't make out and on the right lower you've got what looks like four single-poles. Since it looks like there are ones on there, I'll venture a guess that they were all 15-amp circuits.

Look at all of the conductors leaving those breakers; they all leave that panel and not a single pair feeds power to the lower half. The grounded conductors (the white "neutrals") are all on that bus below the breaker banks but all of the equipment-grounding conductors (the bare "grounds) have all been terminated together under that ground lug on the side of that myers hub and you dn't see any provision for a bonding screw.

All of that says that it isn't a split bus panel and those are continuous power buses from top to bottom. That tells me that somewhere else inside or outside of that building/unit is a main disconnect breaker. Did you find the meter? Was there a little metal door next to it that when opened had a single breaker behind it?

The six throw rule you are thinking about applies to split-bus panels. Those typically hold five or six two pole breakers in the top half for the oven, water heater, and other items that need 240-volt circuits and all of the branch lighting and small appliance circuits are typically in the bottom half of the panel.

When there are six two-pole breakers in the top half of the panel, one of them will feed power to the lugs at the top of the bars at the lower half of the panel. If you look at a split-bus panel and find only five two-pole breakers in the top half, you'll probably see a pair of conductors feeding a large 2-pole breaker in the bottom half. Sometimes you won't see the conductors because the bottom half will be back-fed, but with those the large two pole fed by those cables switches on and provides power to the bottom half.

Here's a picture of a pre-1984 split-bus panel:

This particular configuration is supposed to have a total of four two-pole breakers in the top half and a sub-main breaker in the bottom half. See the cables? They feed power from the bottom of the top bus to the lugs at that large 2-pole breaker in the bottom half. When you look at this, you can see that it's definitely a main panel and as you look at it you'll be able to see that, if this were configured properly with no more than four two-pole breakers in the top half, one could turn power off with only five throws. However, on this home, to turn off all power to this house one must make a total of 7 throws. Can you see why? With only ten more inches of cable and with a little bit of forethought, they could have had this configured as a five throw panel.

Click to Enlarge

83.25 KB.

ONE TEAM - ONE FIGHT!!!

Mike

[hausdok]

Seems the easiest way to make it a five throw panel would be to put a handle on the two 2-pole breaks at top so both switchs can be flipped simultaneously.

Thank you much for all your help.

Nope,

There are two two-pole breakers in the bottom that can be moved up to the top half and those breakers in the top can be moved to the lower half. The electrician will need to extend the cables to that 2-pole breaker at the lower right when it's moved to the top half.

ONE TEAM - ONE FIGHT!!!

Mike

[Richard Moore]

Scott,

Take a look at this thread. https://www.inspectorsjournal.com/forum ... C_ID=10694

There are photos of most of the common split-bus panels there.

[randynavarro]

Im a new home inspector with a quick question.

It should take 6 or less handmovements to turn off all power to home. In a panel with no main disconnect, how do you know if one of the breakers turns off power to the rest?

Thanks,

Scott

Click to Enlarge

53.45 KB

You're thinking that it's a main panel. I don't think it is. It looks like a sub-panel in multi-family housing. Was this a condo or one of several units in a multiplex? All of those 4-pole 30 amp breakers are screaming electric heaters to me, which is also something I see in multiplexes or small condo flats a lot.

You have a total of five two-pole breakers in the top half of that panel; four of them are 30-amps and the other is 40-amps. In the bottom, you have two two-pole 30 amp breakers on the left bank plus a single-pole the size of which I can't make out and on the right lower you've got what looks like four single-poles. Since it looks like there are ones on there, I'll venture a guess that they were all 15-amp circuits.

Look at all of the conductors leaving those breakers; they all leave that panel and not a single pair feeds power to the lower half. The grounded conductors (the white "neutrals") are all on that bus below the breaker banks but all of the equipment-grounding conductors (the bare "grounds) have all been terminated together under that ground lug on the side of that myers hub and you dn't see any provision for a bonding screw.

All of that says that it isn't a split bus panel and those are continuous power buses from top to bottom. That tells me that somewhere else inside or outside of that building/unit is a main disconnect breaker. Did you find the meter? Was there a little metal door next to it that when opened had a single breaker behind it?

The six throw rule you are thinking about applies to split-bus panels. Those typically hold five or six two pole breakers in the top half for the oven, water heater, and other items that need 240-volt circuits and all of the branch lighting and small appliance circuits are typically in the bottom half of the panel.

When there are six two-pole breakers in the top half of the panel, one of them will feed power to the lugs at the top of the bars at the lower half of the panel. If you look at a split-bus panel and find only five two-pole breakers in the top half, you'll probably see a pair of conductors feeding a large 2-pole breaker in the bottom half. Sometimes you won't see the conductors because the bottom half will be back-fed, but with those the large two pole fed by those cables switches on and provides power to the bottom half.

Here's a picture of a pre-1984 split-bus panel:

This particular configuration is supposed to have a total of four two-pole breakers in the top half and a sub-main breaker in the bottom half. See the cables? They feed power from the bottom of the top bus to the lugs at that large 2-pole breaker in the bottom half. When you look at this, you can see that it's definitely a main panel and as you look at it you'll be able to see that, if this were configured properly with no more than four two-pole breakers in the top half, one could turn power off with only five throws. However, on this home, to turn off all power to this house one must make a total of 7 throws. Can you see why? With only ten more inches of cable and with a little bit of forethought, they could have had this configured as a five throw panel.

Click to Enlarge

83.25 KB.

ONE TEAM - ONE FIGHT!!!

Mike

Is this response from Mike O. worth one hour of CE from Washington state? It should be.

[hausdok]

Im a new home inspector with a quick question.

It should take 6 or less handmovements to turn off all power to home. In a panel with no main disconnect, how do you know if one of the breakers turns off power to the rest?

Thanks,

Scott

Click to Enlarge

53.45 KB

You're thinking that it's a main panel. I don't think it is. It looks like a sub-panel in multi-family housing. Was this a condo or one of several units in a multiplex? All of those 4-pole 30 amp breakers are screaming electric heaters to me, which is also something I see in multiplexes or small condo flats a lot.

You have a total of five two-pole breakers in the top half of that panel; four of them are 30-amps and the other is 40-amps. In the bottom, you have two two-pole 30 amp breakers on the left bank plus a single-pole the size of which I can't make out and on the right lower you've got what looks like four single-poles. Since it looks like there are ones on there, I'll venture a guess that they were all 15-amp circuits.

Look at all of the conductors leaving those breakers; they all leave that panel and not a single pair feeds power to the lower half. The grounded conductors (the white "neutrals") are all on that bus below the breaker banks but all of the equipment-grounding conductors (the bare "grounds) have all been terminated together under that ground lug on the side of that myers hub and you dn't see any provision for a bonding screw.

All of that says that it isn't a split bus panel and those are continuous power buses from top to bottom. That tells me that somewhere else inside or outside of that building/unit is a main disconnect breaker. Did you find the meter? Was there a little metal door next to it that when opened had a single breaker behind it?

The six throw rule you are thinking about applies to split-bus panels. Those typically hold five or six two pole breakers in the top half for the oven, water heater, and other items that need 240-volt circuits and all of the branch lighting and small appliance circuits are typically in the bottom half of the panel.

When there are six two-pole breakers in the top half of the panel, one of them will feed power to the lugs at the top of the bars at the lower half of the panel. If you look at a split-bus panel and find only five two-pole breakers in the top half, you'll probably see a pair of conductors feeding a large 2-pole breaker in the bottom half. Sometimes you won't see the conductors because the bottom half will be back-fed, but with those the large two pole fed by those cables switches on and provides power to the bottom half.

Here's a picture of a pre-1984 split-bus panel:

This particular configuration is supposed to have a total of four two-pole breakers in the top half and a sub-main breaker in the bottom half. See the cables? They feed power from the bottom of the top bus to the lugs at that large 2-pole breaker in the bottom half. When you look at this, you can see that it's definitely a main panel and as you look at it you'll be able to see that, if this were configured properly with no more than four two-pole breakers in the top half, one could turn power off with only five throws. However, on this home, to turn off all power to this house one must make a total of 7 throws. Can you see why? With only ten more inches of cable and with a little bit of forethought, they could have had this configured as a five throw panel.

Click to Enlarge

83.25 KB.

ONE TEAM - ONE FIGHT!!!

Mike

Is this response from Mike O. worth one hour of CE from Washington state? It should be.

You know, if I could get them to give me CEU's for every hour of crap I write here, and then could turn around and sell those CEU's off to other Washington inspectors - kind of like selling carbon credits - I could probably shut things down and go sit on the porch with a laptop and get out of all this danged cirque-du-soliel attic scrambling and 'nam tunnel ratting in crawlspaces.

ONE TEAM - ONE FIGHT!!!

Mike