Your minimum PPE for residential breaker box work

[ericsarratt]

They possibly can and often will use smaller conductors than NEC will require.

So, in looking at wire sizes for 200 amp service, if the service providers does not size the wire correctly for the load isn't that a fire hazard for the home owner.

 

[ericsarratt]

Still energized equipment with exposed live parts in my opinion. So PPE required. The "finger-safe" guards are good, but probably not safe against someone who loses situational awareness.

As a great man once said: "Do you feel lucky today?"

Yeah, I tend to err on the side of caution. I'll spend money on safety equipment in a heartbeat for myself, my employees or my subs.

Any arc flash prevention suggestions for the live lugs at the top of a residential breaker box?

Would an insulating blanket (like lineman use) attached to the box with blanket clips over the lug area work?

 

[jim dungar]

Still energized equipment with exposed live parts in my opinion. So PPE required. The "finger-safe" guards are good, but probably not safe against someone who loses situational awareness.

As a great man once said: "Do you feel lucky today?"

Compliance with NFPA70E means you have conducted a risk analysis along with identifying the hazards.

How many 'safety oriented' people are absolutely black and white when it comes to energized electrical parts, yet they are more than willing to put a tank of propane for the grill or a tank of gas for the mower into the back of their vehicle when their kids are in the front?

Exposed lugs are extremely dangerous when something can make contact with them, they are not as much when they are simply being viewed without current flowing through them.

Remember, always create safe work environments.

 

[jim dungar]

Yeah, I tend to err on the side of caution. I'll spend money on safety equipment in a heartbeat for myself, my employees or my subs.

Any arc flash prevention suggestions for the live lugs at the top of a residential breaker box?

Would an insulating blanket (like lineman use) attached to the box with blanket clips over the lug area work?

How is an arc flash going to occur on the line side of a turned off main? Always perform a risk analysis on the tasks and equipment you are working on.

 

[hillbilly1]

Q

How is an arc flash going to occur on the line side of a turned off main? Always perform a risk analysis on the tasks and equipment you are working on.

Quite easily, you have conductors that feed that line side that are live, a damaged conductor that becomes faulted when something is moved or jarred. A misplaced or dropped tool. Breaker failure, all kinds of scenarios.

 

[kwired]

I was talking with an poco engineer, and he said they just use infinite buss in their calculations to give the customer.

They may also assign same value for some variables even if the actual is different.

Example they may assign a certain available fault current for a particular size transformer even though they could have several same KVA rating with different impedance marked on the nameplate. They may also assume a secondary conductor size, length etc. even though every install will definitely have some variances. Or they might just give you a value for secondary terminals (probably based on infinite bus, and also probably an assumed transformer impedance instead of actual impedance, but you have to figure in what the conductors will take away from that.

 

[tortuga]

Any arc flash prevention suggestions for the live lugs at the top of a residential breaker box?

Don't take this the wrong way but since it does not say your occupation is electrician I'd just hire an experienced master electrician to do the work in your service loadcenter until you get all the training you need to be a 'qualified person' to work in a energized loadcenter.

One of the main safety issues I look out for for doing hot work on a panel is proper working space, make sure there is plenty of room to move around and set your tools down.
I was about to open up a panel in a garage last week and noticed they had a can of gas and some rags and other automotove junk below the panel.
All that got moved.

 

[letgomywago]

Don't take this the wrong way but since it does not say your occupation is electrician I'd just hire an experienced master electrician to do the work in your service loadcenter until you get all the training you need to be a 'qualified person' to work in a energized loadcenter.

One of the main safety issues I look out for for doing hot work on a panel is proper working space, make sure there is plenty of room to move around and set your tools down.
I was about to open up a panel in a garage last week and noticed they had a can of gas and some rags and other automotove junk below the panel.
All that got moved.

work space, lighting even a head light, good proper tooks, limit live exposed parts. dry good fitting leather gloves at the minimum and youll be way ahead of the game for standard residential for your employees. 70e youd need to pull the meter for even rearanging the existing breakers.

 

[jim dungar]

Quite easily, you have conductors that feed that line side that are live, a damaged conductor that becomes faulted when something is moved or jarred. A misplaced or dropped tool. Breaker failure, all kinds of scenarios.

It looks like you have done a risk analysis as I suggested.

The next step is to decide how mitigate these risks.

 

[Joethemechanic]

if the service providers does not size the wire correctly for the load isn't that a fire hazard for the home owner.

It's triplex in free air. It dissipates the I2R heating very easily. It's not like a conductor in a jacket with other conductors inside a wall and maybe surrounded with insulation. Inside a space like that I2R heating builds up to high temperatures because the heat can't dissipate.



So it is not sized incorrectly. What you install is covered by the NEC. The power company sets their own standards guided by the National Electrical Safety Code

 

[ericsarratt]

It's triplex in free air. It dissipates the I2R heating very easily. It's not like a conductor in a jacket with other conductors inside a wall and maybe surrounded with insulation. Inside a space like that I2R heating builds up to high temperatures because the heat can't dissipate.

View attachment 2565975

So it is not sized incorrectly. What you install is covered by the NEC. The power company sets their own standards guided by the National Electrical Safety Code

Got it. I did not think about the cooling effect of free air circulation on the wires. Thanks.

I had to study the NESC to get one of my licenses.

 

[kwired]

It's triplex in free air. It dissipates the I2R heating very easily. It's not like a conductor in a jacket with other conductors inside a wall and maybe surrounded with insulation. Inside a space like that I2R heating builds up to high temperatures because the heat can't dissipate.

View attachment 2565975

So it is not sized incorrectly. What you install is covered by the NEC. The power company sets their own standards guided by the National Electrical Safety Code

Not a fire hazard as you mentioned, they sometimes make long runs though and that turns into having voltage drop issues. VD might be somewhat acceptable for the typical full load conditions, but doesn't do so well during motor startups and such.

 

[hillbilly1]

Got a job coming up that the poco has #2 triplex running about 600’ away to the transformer, feeds three 200 amp services. Rebuilding the services, and told the owner he needs to get the poco to upgrade their line due to voltage drop.

 

[Joethemechanic]

Not a fire hazard as you mentioned, they sometimes make long runs though and that turns into having voltage drop issues. VD might be somewhat acceptable for the typical full load conditions, but doesn't do so well during motor startups and such.

Yeah like that time I tried to test that big air compressor I bought at the auction and blew the primaries

 

[busman]

In the attic you might consider a hard-hat. Those roofing nails are pointy!

I stopped wearing a baseball cap when I had a close call with a energized foil insulation in a crawlspace and a very sweaty cap. Since that day, it is hard hat only. Not an approved insulator, but I feel much better with a big piece of plastic over my dome than a sweaty cap.

Mark

 

[garbo]

I have done hundreds of 100 & 200 amp services and always wear eye protection. Back in the 1960 & 70's never wore gloves to tie in services . One thing that I worried about if you do create an arc flash the ultility company does an extremely poor job of overload protection. They only have a fuse on the primary side of transformers. When I asked a PECO lineman about their overload protection he said they rather have your house burn down the thier oversized fuse open and require a bucket truck to respond.

 

[ericsarratt]

Still energized equipment with exposed live parts in my opinion. So PPE required. The "finger-safe" guards are good, but probably not safe against someone who loses situational awareness.

As a great man once said: "Do you feel lucky today?"

Exactly!

Here is an article I found recently in Fine Home Building #173, September 2005. This is the exact scenario I want to avoid.

Any input on how to avoid this scenario would be helpful.

 

[gadfly56]

Exactly!

Here is an article I found recently in Fine Home Building #173, September 2005. This is the exact scenario I want to avoid.
View attachment 2566646
Any input on how to avoid this scenario would be helpful.

HO: "Excuse me..."
Electrician: [Takes tool out of the enclosure, turns to HO] "Be right with you, I need to concentrate on this."

 

[TwoBlocked]

Exactly!

Here is an article I found recently in Fine Home Building #173, September 2005. This is the exact scenario I want to avoid.

Any input on how to avoid this scenario would be helpful.

In industrial situations I will often put up red danger tape to keep rubberneckers back. Some facilities require it. It's in 70E, too.

 

[ericsarratt]

In industrial situations I will often put up red danger tape to keep rubberneckers back. Some facilities require it. It's in 70E, too.

Thanks! I'm taking 70E in October in Maryland.