Choice of power

[Jay Barracato]

I can get full performance from my rig with 3 20 amp circuits. I bought a 30 amp racpak with L14-30 input and 3 20 amp edison outputs mainly to couple with a honda generator as a portable power source. I built a L14-30 male to female supply and a 4 prong dryer plug adapter.



I would like to have similar access to a 50 amp supply. It seems my two choices are to get a dedicated 50 amp racpak and similar supply (in the correct gauge) or to build (or have built) a L14-50 to 30 amp breaker to L14-30 to step down a 50 amp supply. I think this would have to be in a closed box as I would like to have it rack mounted as well.



(I am really not sure if it would be kosher to simply make a L14-50 to L14-30 adapter on a cable sized for 50 amps. It seems to me that the racpak shouldn't be able to draw more than 30 amps and the only thing that wouldn't be at its rated capacity fro the supply is the L14-30.)



I would be interested in hearing any opinions on these choices, or other ones I did not consider.

 

[Shane Presley]

Re: Choice of power

I can get full performance from my rig with 3 20 amp circuits. I bought a 30 amp racpak with L14-30 input and 3 20 amp edison outputs mainly to couple with a honda generator as a portable power source. I built a L14-30 male to female supply and a 4 prong dryer plug adapter.



I would like to have similar access to a 50 amp supply. It seems my two choices are to get a dedicated 50 amp racpak and similar supply (in the correct gauge) or to build (or have built) a L14-50 to 30 amp breaker to L14-30 to step down a 50 amp supply. I think this would have to be in a closed box as I would like to have it rack mounted as well.



(I am really not sure if it would be kosher to simply make a L14-50 to L14-30 adapter on a cable sized for 50 amps. It seems to me that the racpak shouldn't be able to draw more than 30 amps and the only thing that wouldn't be at its rated capacity fro the supply is the L14-30.)



I would be interested in hearing any opinions on these choices, or other ones I did not consider.

Hey Jay, you can't have a 30 amp connection in line with a 50 amp cable.. before being breakered...

I'm thinking your best bet is a 50 amp feed to small 4 space breaker panel. use a 50 amp breaker as the main(space 1 and 2), and a 30 amp breaker (space 3 and 4) to feed a panel mount 30 amp twist in the bottom of the panel box. That will get your rack pack brought down to 30. Like everything else this advice is ''at your own liability''.

 

[Silas Pradetto]

Re: Choice of power

Use one 50-amp racpak and sell the 30-amp one. There is nothing wrong with supplying the 50-amp pack with only 30 amps.



Why only 3 20-amp circuits on your 30-amp unit? That is an unbalanced load. I'd want two circuits per leg if it were me. And on the 50-amp pack, I'd want six 20-amp circuits, three per leg, even if I wasn't going to use them right away.

 

[Jay Barracato]

Re: Choice of power

I can get full performance from my rig with 3 20 amp circuits. I bought a 30 amp racpak with L14-30 input and 3 20 amp edison outputs mainly to couple with a honda generator as a portable power source. I built a L14-30 male to female supply and a 4 prong dryer plug adapter.



I would like to have similar access to a 50 amp supply. It seems my two choices are to get a dedicated 50 amp racpak and similar supply (in the correct gauge) or to build (or have built) a L14-50 to 30 amp breaker to L14-30 to step down a 50 amp supply. I think this would have to be in a closed box as I would like to have it rack mounted as well.



(I am really not sure if it would be kosher to simply make a L14-50 to L14-30 adapter on a cable sized for 50 amps. It seems to me that the racpak shouldn't be able to draw more than 30 amps and the only thing that wouldn't be at its rated capacity fro the supply is the L14-30.)



I would be interested in hearing any opinions on these choices, or other ones I did not consider.

Hey Jay, you can't have a 30 amp connection in line with a 50 amp cable.. before being breakered...

I'm thinking your best bet is a 50 amp feed to small 4 space breaker panel. use a 50 amp breaker as the main(space 1 and 2), and a 30 amp breaker (space 3 and 4) to feed a panel mount 30 amp twist in the bottom of the panel box. That will get your rack pack brought down to 30.

Why would I need the 50 amp breaker in the box if the supply is already breakered at 50 back at the panel?



I think somewhere in pulling through the NEC I saw something about undersized supply if it was within some short distance of the panel, but I am not sure how that applies to connectors.

 

[Jay Barracato]

Re: Choice of power

Silas, i believed it is balanced by having 1 20 on X leg, one on Y, and one on X+Y.



Just trading up to the 50 amp unit was not an option I had thought of. Thanks

 

[Silas Pradetto]

Re: Choice of power

Silas, i believed it is balanced by having 1 20 on X leg, one on Y, and one on X+Y.



Just trading up to the 50 amp unit was not an option I had thought of. Thanks

You can't put one on X+Y unless it's a 240VAC circuit. Standard 120VAC circuits are wired hot to neutral, so there would be two on one leg and one on the other the way he described it.

 

[Jay Barracato]

Re: Choice of power

Sorry, you made me confused about what I actually have at home. It is the 4 breaker 2 rack space motion lab unit.

 

[Shane Presley]

Re: Choice of power

I can get full performance from my rig with 3 20 amp circuits. I bought a 30 amp racpak with L14-30 input and 3 20 amp edison outputs mainly to couple with a honda generator as a portable power source. I built a L14-30 male to female supply and a 4 prong dryer plug adapter.



I would like to have similar access to a 50 amp supply. It seems my two choices are to get a dedicated 50 amp racpak and similar supply (in the correct gauge) or to build (or have built) a L14-50 to 30 amp breaker to L14-30 to step down a 50 amp supply. I think this would have to be in a closed box as I would like to have it rack mounted as well.



(I am really not sure if it would be kosher to simply make a L14-50 to L14-30 adapter on a cable sized for 50 amps. It seems to me that the racpak shouldn't be able to draw more than 30 amps and the only thing that wouldn't be at its rated capacity fro the supply is the L14-30.)



I would be interested in hearing any opinions on these choices, or other ones I did not consider.

Hey Jay, you can't have a 30 amp connection in line with a 50 amp cable.. before being breakered...

I'm thinking your best bet is a 50 amp feed to small 4 space breaker panel. use a 50 amp breaker as the main(space 1 and 2), and a 30 amp breaker (space 3 and 4) to feed a panel mount 30 amp twist in the bottom of the panel box. That will get your rack pack brought down to 30.

Why would I need the 50 amp breaker in the box if the supply is already breakered at 50 back at the panel?



I think somewhere in pulling through the NEC I saw something about undersized supply if it was within some short distance of the panel, but I am not sure how that applies to connectors.

Yes you're correct - You would only need the 50amp breaker if, you're being supplied by something larger than 50... or the wire it's being fed on...