Bridgeport mill supply breaker question

[A747]

I’m in the process of wiring a Series 1 Bridgeport mill from my 220V power source. I have both the power input and motor output cables wired to the VFD. The other end of the incoming 220V power side will be plugged into my existing 50 amp emergency generator inlet box. A single 40 amp breaker connects to the garage subpanel. My final step was to swap the 40 amp breaker with a 20 amp breaker to supply the Bridgeport. The problem when I attempted to swap out the breakers was that the power cables for the 40 amp breaker were a tiny bit too large in diameter to fit the 20 amp connector terminals.

I can only think of two options.. First is to tie into the bus bar upstream of the 40 amp breaker with a 12/4 SO cable (what I’m currently using) and terminate into a separate breaker box for the 20 amp breaker and then directly connect the VFD to the breaker. I don’t know if this is even code legal. My second option is to tie in a transfer switch upstream to the 40 amp breaker box and have a separate 20 amp breaker box similar to option #1.

I’d be happy to hear of other options I haven’t thought of.

 

[mm08822]

Your generator inlet box should have a plug in it, not a receptacle when used for intended purpose. Not following this requirement means your are using a suicide cord from the gen.

The PIB cb also needs to be interlocked with the panel supply for its original purpose. This won't work to provide power to the vfd.

You should just run a dedicated 12-2 ckt to the vfd and not screw up the PIB circuit.

 

[smyron]

Change the full size 40 amp brker to a quad 40/20 brker. connect vfd feed to outside 20's. Every thing down stream is 20 amp limited

 

[A747]

Change the full size 40 amp brker to a quad 40/20 brker. connect vfd feed to outside 20's. Every thing down stream is 20 amp limited

I never knew that such a creature existed, I just placed an order online for a 40/20 quad breaker and that should be the solution to my problem when it arrives. The only unknown is if it will fit in the original breaker box. I very much appreciate the help otherwise I would have been spinning my wheels trying to figure out the solution.

In regards to the emergency generator power inlet box, it’s a standard male plug with a female cord from my generator, so no suicide plug. With my solar system installed, the backup generator, if ever used, will run to provide power to the garage only during a power outage

 

[mm08822]

I never knew that such a creature existed, I just placed an order online for a 40/20 quad breaker and that should be the solution to my problem when it arrives. The only unknown is if it will fit in the original breaker box. I very much appreciate the help otherwise I would have been spinning my wheels trying to figure out the solution.

In regards to the emergency generator power inlet box, it’s a standard male plug with a female cord from my generator, so no suicide plug. With my solar system installed, the backup generator, if ever used, will run to provide power to the garage only during a power outage

While you may not have a suicide cord between gen and PIB, you have the PIB wired as a SUICIDE PLUG.
The plug terminals in the PIB can be energized from the grid. You can't have an interlock on the PIB circuit if you are able to power the VFD from the grid through it.

Doesn't it seem bass ackwards that your vfd power supply cord has a female cap on it instead of a plug??

 

[wyliesdiesels]

I never knew that such a creature existed, I just placed an order online for a 40/20 quad breaker and that should be the solution to my problem when it arrives. The only unknown is if it will fit in the original breaker box. I very much appreciate the help otherwise I would have been spinning my wheels trying to figure out the solution.

In regards to the emergency generator power inlet box, it’s a standard male plug with a female cord from my generator, so no suicide plug. With my solar system installed, the backup generator, if ever used, will run to provide power to the garage only during a power outage

You shouldve checked the make and model on the breaker panel first. You cant just put any brand and model breaker in the panel.

 

[A747]

While you may not have a suicide cord between gen and PIB, you have the PIB wired as a SUICIDE PLUG.
The plug terminals in the PIB can be energized from the grid. You can't have an interlock on the PIB circuit if you are able to power the VFD from the grid through it.

Doesn't it seem bass ackwards that your vfd power supply cord has a female cap on it instead of a plug??

In order to get power to the power inlet box, these four breakers need to be closed, the 200 amp service breaker to my main house panel, the 100 amp breaker that supplies the detached garage subpanel, the 50 amp breaker in the garage subpanel that supplies the 40 amp breaker sub-sub panel that supplies the PIB, then the PIB. The 200 amp and 100 amp breakers are normally closed, the 50 amp and 40 amp breakers in the garage are normally open. How many more layers of additional breakers or disconnects do you think I should add before I eliminate all danger from my SUICIDE PLUG. There is a cover over the PIB for another level of safety which I could add a lock when not in use.You do understand that the PIB has a male plug so that the cord from the generator has to be female to prevent the dreaded SUICIDE PLUG. The PIB for my power source is what I originally had to work with and the reason why the plug had to be female. It would have worked, what is the issue?

You shouldve checked the make and model on the breaker panel first. You cant just put any brand and model breaker in the panel.

This is my deepest foray into residential electrical work. Previous projects involved running yellow and white Romex for additional outlets in the garage.I’m just starting to discover the lack of standardization in some of the electrical components field.

 

[mm08822]

In order to get power to the power inlet box, these four breakers need to be closed, the 200 amp service breaker to my main house panel, the 100 amp breaker that supplies the detached garage subpanel, the 50 amp breaker in the garage subpanel that supplies the 40 amp breaker sub-sub panel that supplies the PIB, then the PIB. The 200 amp and 100 amp breakers are normally closed, the 50 amp and 40 amp breakers in the garage are normally open. How many more layers of additional breakers or disconnects do you think I should add before I eliminate all danger from my SUICIDE PLUG. There is a cover over the PIB for another level of safety which I could add a lock when not in use. You do understand that the PIB has a male plug so that the cord from the generator has to be female to prevent the dreaded SUICIDE PLUG. The PIB for my power source is what I originally had to work with and the reason why the plug had to be female. It would have worked, what is the issue?

This is my deepest foray into residential electrical work. Previous projects involved running yellow and white Romex for additional outlets in the garage. I’m just starting to discover the lack of standardization in some of the electrical components field.

You are using the PIB for the wrong purpose. You are back-feeding it, which should not be possible and you obviously don't have the interlock. Obviously not installed according to mfr's instructions, which listing of the product is dependent upon.
This is hack work and 5 more cb's won't eliminate the risk of an energized male plug - all of this extra hardware just makes for more confusion. Where is your common sense?

 

[wyliesdiesels]

You are using the PIB for the wrong purpose. You are back-feeding it, which should not be possible and you obviously don't have the interlock. Obviously not installed according to mfr's instructions, which listing of the product is dependent upon.
This is hack work and 5 more cb's won't eliminate the risk of an energized male plug - all of this extra hardware just makes for more confusion. Where is your common sense?

Agreed. What a fricken mess

 

[PCustoms]

Agreed. What a fricken mess

I'm having deja Vu to another thread posted yesterday. Other then the fact that the breaker sizes are clearly different I'd think it's the same trainwreck.

Time to start over.

 

[dave*99]

In order to get power to the power inlet box, these four breakers need to be closed, the 200 amp service breaker to my main house panel, the 100 amp breaker that supplies the detached garage subpanel, the 50 amp breaker in the garage subpanel that supplies the 40 amp breaker sub-sub panel that supplies the PIB, then the PIB. The 200 amp and 100 amp breakers are normally closed, the 50 amp and 40 amp breakers in the garage are normally open. How many more layers of additional breakers or disconnects do you think I should add before I eliminate all danger from my SUICIDE PLUG. There is a cover over the PIB for another level of safety which I could add a lock when not in use.You do understand that the PIB has a male plug so that the cord from the generator has to be female to prevent the dreaded SUICIDE PLUG. The PIB for my power source is what I originally had to work with and the reason why the plug had to be female. It would have worked, what is the issue?

99 breakers in series doesn't make it safe. An INTERLOCK makes it safe. You don't have one. The PIB MUST be connected to an interlock. It's an inlet. Not an outlet. You can install one or expect the experts on this board to continue their commentary about the need for one.

 

[A747]

Some how this thread went off the rails when someone mentioned SUICIDE PLUG. Just to be clear, with the installation of solar panels and a backup battery, the emergency generator will probably never be used for its original purpose. In fact, it has never been run since it was unboxed a couple of years ago. The replacement quad 40/20 amp breaker will allow me to use the current cable feeding the PIB with the 20 amp breaker. I will probably leave the wiring to the PIB disconnected from the 40 amp breaker for now since it will not be needed.

Looking ahead , should I have a complete failure of my PV system and I need to run the generator, I don’t see any way to install an interlock system with my current breaker configuration at my main service panel. From the photo, the 200 amp main service breaker is at the very top and the 100 amp supply breaker to the garage is the second breaker from the bottom. The garage breaker will always remain closed so how will an interlock system work in this case. The only way I can see is to use a breaker lockout device for the 200 amp incoming breaker. It’s a lot safer than a mechanical interlock which will depend on the competence of the person installing the kit. Anyone know if it can be used as an alternate safety device?

 

[wyliesdiesels]

Some how this thread went off the rails when someone mentioned SUICIDE PLUG. Just to be clear, with the installation of solar panels and a backup battery, the emergency generator will probably never be used for its original purpose. In fact, it has never been run since it was unboxed a couple of years ago. The replacement quad 40/20 amp breaker will allow me to use the current cable feeding the PIB with the 20 amp breaker. I will probably leave the wiring to the PIB disconnected from the 40 amp breaker for now since it will not be needed.

Looking ahead , should I have a complete failure of my PV system and I need to run the generator, I don’t see any way to install an interlock system with my current breaker configuration at my main service panel. From the photo, the 200 amp main service breaker is at the very top and the 100 amp supply breaker to the garage is the second breaker from the bottom. The garage breaker will always remain closed so how will an interlock system work in this case. The only way I can see is to use a breaker lockout device for the 200 amp incoming breaker. It’s a lot safer than a mechanical interlock which will depend on the competence of the person installing the kit. Anyone know if it can be used as an alternate safety device?

It wont. you need a separate feed from the PIB to the main service panel to make this compliant. The PIB shouldve never terminated in the subpanel...

 

[Norcal]

Another problem is there are Siemens breakers being used, Siemens is not UL Classified to be used in Eaton BR (Zinsco II) panels

 

[wyliesdiesels]

This is my deepest foray into residential electrical work. Previous projects involved running yellow and white Romex for additional outlets in the garage. I’m just starting to discover the lack of standardization in some of the electrical components field.

what lack of standardization are you referring to? standardization with breakers?