Bull Dog Pushmatic Electrical panel and Circuit Breakers

highdeserthome · 01-11-2012, 01:33 PM

When I buy an electrical box (breaker panel/load center) first intended for a sub-panel fed from the 50 amp Pushmatic, can I use the same electrical box as the only electrical box later should I completely remove the Pushmatic/Bulldog?

If I can use the same box, I will get one with max load over 100 amps but only set up for less, just for the 50 amp breaker.

Is there a type of box for a sub-panel and another for the main panel, or the same type will serve either per application?

Julius793 · 01-11-2012, 01:50 PM

Quote:

Originally Posted by highdeserthome

When I buy an electrical box (breaker panel/load center) first intended for a sub-panel fed from the 50 amp Pushmatic, can I use the same electrical box as the only electrical box later should I completely remove the Pushmatic/Bulldog?

If I can use the same box, I will get one with max load over 100 amps but only set up for less, just for the 50 amp breaker.

Is there a type of box for a sub-panel and another for the main panel, or the same type will serve either per application?

You can reuse it assuming it has a main breaker. In addition when serving as a sub the ground and neutral bus must be disconnected from each other, and when/if it turns into the regular panel the buses must be reconnected.

highdeserthome · 01-11-2012, 05:28 PM

In case of emergency if one Pushmatic CB becomes defective, can I put two circuits onto one CB for a little while when I construct a sub-panel?

I think I can and this is NOT a safety issue even if it may not be to NEC code.

This can be a functionality issue.

If I put two hots 12 AWG wire onto the same 20 amp CB, what will happen? The chance of fire is not greater I think.

If both circuits are just for lights (and I am aware of it), it will never be overloaded, and if it were overlanded the same CB will work.

If I know the demand on each circuit will never be more than 10 amps, then doubling two such circuits into the same CB will not be any more unsafe.

My point is about the urgency of building a subpanel. May be I can wait until any Pushmatic need replacement at high price.

kbsparky · 01-11-2012, 08:07 PM

Quote:

Originally Posted by Julius793

Maybe I should have been a little nicer but hey the the point of the example was that if you overload your sub there needs to be a main. Sparky thought he's real smart and commented in the example I gave it doesn't necessarily need to be an overload because they could be divided between phases. Is that the point???

I perceive from the subsequent messages posted here that one or more posts are missing from this discussion.

My comment about your example was made because you did not reflect real life conditions. Not that the loads could be divided, but that they would be divided among the legs. Making the example given a moot point.

highdeserthome · 01-13-2012, 07:26 PM

I just found out, it appears very much so, that the 50 amp pushmatic is actually two CB's of different opposite phase. One of this pushmatic is like two modern CBs.

I actually have two 50 amp CBs; just that the two may trip at once, will if one does. The push action applies to both CBs.

highdeserthome · 01-26-2012, 01:51 PM

One of the CBs trips early.

Yesterday, one 20 amp CB trips for no good reason when a 12 amp shopvac was used. I plug it into another 20 amp circuit, some operation, and it did not trip.

KStatefan · 01-26-2012, 02:06 PM

Why not just replace the panel now? I do not under stand why you would want to put a sub-panel in now with the plan of moving it to the main panel later.

highdeserthome · 01-26-2012, 02:15 PM

Quote:

Originally Posted by KStatefan

Why not just replace the panel now? I do not under stand why you would want to put a sub-panel in now with the plan of moving it to the main panel later.

Taking out the service cables and re-landing will require a permit and likely requires an electrician.

I can do most and hire a electrican to do just the service cable part later.

If the Pushmatic main 100 amp breakers does not fail to close, I can forever use a sub-panel setup and never reland the service cables.

highdeserthome · 01-26-2012, 05:48 PM

Is it true for NEC code that if there are two CBs in series, the wire needs only to match that of the lower rated CB?

I ask because I intend to feed from a 50 amp Pushmatic into the main CB of a sub-panel.

If the main of a sub-panel is 100 amps CBs, and the feed is from the Pushmatic 50 amp, can I use wire for 50 amps, not 100 amps.

kbsparky · 01-27-2012, 02:50 AM

There are specific rules in the Code governing the use of tap conductors, and overcurrent protection.

These rules cover things like distance, and overall capacity of the source, and the tap conductor size, and type of cable used.

You have to be more specific here: How far away is your proposed sub-panel, and what wiring methods do you intend to use?

highdeserthome · 01-27-2012, 12:22 PM

Quote:

Originally Posted by kbsparky

There are specific rules in the Code governing the use of tap conductors, and overcurrent protection.

These rules cover things like distance, and overall capacity of the source, and the tap conductor size, and type of cable used.

You have to be more specific here: How far away is your proposed sub-panel, and what wiring methods do you intend to use?

1. The sub-panel will be right next to the existing Pushmatic Bulldog, a foot away.

2. I plan to get a 100A-125A load center with main CB of 100 amps.

3. I will punch two holes thru the side of the existing Bulldog box. One about 1 inch for the short 2-3 feet 8 gauge wires that feed from the 50 amp Pushmatic CB, the other larger hole about 1.5-2 inches for the 16 12 gauge romex sections about 2-3 feet long each, using only the black as the hot. (the white and bare wire will not be used, just dangle with as much cut off as possible and taped to conceal them)

3.There will be conduits through both holes connected to similar holes on the side of the new load center.

4. I will connect the two 8 gauge wires from the 50 amp Pushmatic CB to the 100 amp main CB of the new load center. The question is whether 8 AWG is enough.

5. I will use one wire nut (cap) each to connect the hot of each circuit,

6. The other end of each of the romex section will be terminated onto a new 20 amp CB.

7. The neutral will not be touched. They will all remain at the same place at the Bulldog Pushmatic box.

rrolleston · 01-27-2012, 12:32 PM

You need min 6 gauge for 50 amps

rrolleston · 01-27-2012, 12:35 PM

You will have to check a conduit fill chart to see whether the that will be enough for the 16 12 gauge wires and I think the neutrals and grounds have to be in the same panel.

Meant I think all your hots neutrals and grounds have to be in the same panel.

highdeserthome · 01-27-2012, 12:42 PM

Quote:

Originally Posted by rrolleston

You will have to check a conduit fill chart to see whether the that will be enough for the 16 12 gauge wires and I think the neutrals and grounds have to be in the same panel.

If the neutrals need to be in the same panel, I will need another two 6 AWGs for the neutral and connect them to a bonding bar in the new load center. Or one 4 AWG wire will do. Can I use just one 6 AWG for the neutrals.

There is no ground for this house, all two-wire outlets.

May be I need to punch two holes for the Romex sections and split them into 8 each.

rrolleston · 01-27-2012, 12:50 PM

Sub panels need to be four wire. But since it's only a two wire system I am lost. Maybe someone with more experience can help and we will both learn. Usually you would run four six gauge wires to a sub panel.

Really sounds better to have your meter pulled and just install the new panel in the place of this one. But if done properly it may work.