Disconnect ground first?

[Becker Electric]

What are your thoughts, if your in a situation where you have to work live, about disconnecting the ground from a receptacle first. Of course generally first to make, last to break and all that but If you’re holding the yoke in one hand and unscrewing the hot wire with a screwdriver in the other, ungrounding the yoke might lower the chance of current passing through the chest in the event of accidentally touching the hot terminal, it'd seek ground through feet or another path or maybe not at all if you yourself are ungrounded. Any thoughts on this approach? What other risks may be more likely to happen by disconnecting the ground first?

 

[infinity]

Any thoughts on this approach?

Yes IMO it's safer for the reason you've mentioned. With the EGC disconnected all of the metal parts of the receptacle (yoke, screws, etc.) are no longer a path for the current to travel if you accidentally touch the ungrounded conductor. You can hold the device in your hand and as long as you're not grounded some other way or are touching the neutral you won't become part of the current path when contacting the hot leg. Although I would always disconnect the EGC first I would wear gloves when doing so.

 

[busman]

I would always be wearing hot gloves for this and would disconnect the EGC first to lessen the risk of arc.

Mark

 

[electrofelon]

Definitely best to get grounded objects out of the way. Not sure where that first to make, last to break phrase comes from, just nore grounding nonsense.

 

[electrofelon]

Here is what artificial unintelligence says

First to make, last to break" refers to the safety rule for connecting and disconnecting electrical circuits, which dictates that the ground wire should be the first to be connected and the last to be disconnected. This order ensures a continuous ground path is established before current can flow, providing a crucial safety measure to protect against shocks or equipment damage by offering an alternate path for fault current away from the person making the connection.
Why connect the ground first?

Safety from Shocks:
If a hot wire is accidentally energized, the ground connection provides an immediate path for fault current to flow to the earth, rather than through a person.

 

[infinity]

Safety from Shocks:
If a hot wire is accidentally energized, the ground connection provides an immediate path for fault current to flow to the earth, rather than through a person

Yup AI isn't there yet. The first make last break refers to a plug where the ground pin is longer than the hot and the neutral pins.

 

[electrofelon]

Yup AI isn't there yet. The first make last break refers to a plug where the ground pin is longer than the hot and the neutral pins.

Okay yeah, a plug and receptacle is a good example of where that phrase would apply

 

[Joethemechanic]

In a panel I connect ground first so I don't have a long bare piece of copper just waiting to get knocked into something hot

 

[Becker Electric]

feels like when dealing with a panel hooking the ground up first makes the most sense no?

 

[electrofelon]

feels like when dealing with a panel hooking the ground up first makes the most sense no?

It doesnt really matter, but i usually do just because they tend to be more in the back, and you know where they all go.

 

[Becker Electric]

Yes IMO it's safer for the reason you've mentioned. With the EGC disconnected all of the metal parts of the receptacle (yoke, screws, etc.) are no longer a path for the current to travel if you accidentally touch the ungrounded conductor. You can hold the device in your hand and as long as you're not grounded some other way or are touching the neutral you won't become part of the current path when contacting the hot leg. Although I would always disconnect the EGC first I would wear gloves when doing so.

So would you hook it back up, hot first?

 

[Little Bill]

So would you hook it back up, hot first?

Why would it be hot if you're installing it in the panel?
If installing a new circuit, it doesn't matter the order you put the conductors in. However, as mentioned, the ground and neutral is in the back and easiest to install first.
Technically, you should have the main off.

 

[Becker Electric]

Why would it be hot if you're installing it in the panel?
If installing a new circuit, it doesn't matter the order you put the conductors in. However, as mentioned, the ground and neutral is in the back and easiest to install first.
Technically, you should have the main off.

Sorry, I wasn’t clear. I was referring to the receptacle. If one chooses to disconnect ground first on a hot receptacle, the question is do they chose to hook up hot first when connecting receptacle

 

[electrofelon]

Sorry, I wasn’t clear. I was referring to the receptacle. If one chooses to disconnect ground first on a hot receptacle, the question is do they chose to hook up hot first when connecting receptacle

Yes in general when working on something hot, I would do EGC first to come off, and last to go back on.

 

[ggunn]

Okay yeah, a plug and receptacle is a good example of where that phrase would apply

Also car batteries.

 

[electrofelon]

Also car batteries.

I never noticed my car having an EGC

 

[LarryFine]

I never noticed my car having an EGC

 

[kwired]

I never noticed my car having an EGC

Disconnect the battery terminal that is bonded to the frame first, typically the negative, especially if using a non insulated tool to loosen the terminal.

 

[Joethemechanic]

Disconnect the battery terminal that is bonded to the frame first, typically the negative

But yet the HV side of the ignition operates positive ground

 

[kwired]

But yet the HV side of the ignition operates positive ground

View attachment 2579295

Old school ignition coil is a separately derived source and they can ground either end of it. Performance of the spark plug is probably a reason they do it the way they do.