Got a question for the sparkies out there. 100AMP service, main breaker is below the meter outside. Inside is the breaker box, a PushMatic.
The are 8 spots for fullsized breakers. 3 of those have “twins” (2 small breakers in one fullsize spot). Going from positiosn 1 thru 8 here are the amp ratings:
15 amp
15 amp
15 amp and 20 amp
15 amp
15 amp and 20 amp
20 amp and 15 amp
30 amp @ 240v in position 7 & 8.
Can this service handle another 30 amp 240volt circuit for a dryer/washer combo?
The existing 30 amp 240 breaker serves a small panel by the pool with a 240v 20 amp and a 120v 20 amp circuit.
*If* another 30amp CAN be safely added, could the existing 30AMP be replaced with a 60 amp that feeds a small box that would contain both the 30 amp 240 circuits?
I am leaning towards that the main is “FULL”.
Replies
what size main...
what size wire to the sub-panel...
you have got to give up a bunch mare information...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
The main is 100AMP and the leads to the panel look like 4's.
verfy the cable size fer sure to the sub-panel....
the data sheet says - "how many spaces available" and how many do you gotta have...
and over information us on the sub-panel....
how many wire hook ups to each panel???
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
The data sheet is gone. Musta flaked off before my sis bought this place. There's no door to the panel if there ever was one. Just the flush rimmed cover that sits against the drywall (painted to match of course).
2 hots, neutral and ground, going from the mainbreaker (it's with the meter) to the panel (subpanel more accurate?).
I think I'd dump it. It's obsolete.
I agree. Around here $1500.00 - $2000.00 will get you a brand spanking new 200 amp service.
EricI Love A Hand That Meets My Own,
With A Hold That Causes Some Sensation.
Martha & firebird, yes replacement upgrade would be good long term aim. But right now that's not in the budget.
I just wanna know if this panel/service "as is" can be added on to as per above.
Table 310-15 (b) (6) entitles #4 Copper for a 100 amp service.
Your panel stacks up like this:
Phase A Phase B
15 15
15 + 20 15
15 + 20 20 + 15
30 30 [240v ckt.]
115 95 Amperes
But that means nothing. It depends on what the actual loads on each breaker are. For instance, a 15 amp breaker might only operate a bedroom lamp and a clock radio to listen to Art Bell. On the other hand, it you are running your pool and then add on 30 amps for the dryer, you would be pushing it. May I suggest a gas dryer. Sunshine works too. [Solar power}
You will have to specify exactly what is on each circuit and what, at most, will be running at the same time.
~Peter
[Note: I've used the Courier font to hopefully make the columns line up. Shift + ENTER avoids the space between lines.]
Looks to me like the current service isn't overloaded (115A on a 100A service is fine, given that you'll never see full load on all circuits simultaneously).The service can probably handle another 30A load, but that's about the limit. There's probably some code on this somewhere, but I can never find anything in that darn book.Note that some panels list limits as to the number of half breakers that can be installed, or what slots can receive them. It's possible the panel manufacturers have this online nowadays, if the decal is gone.
Pushamatics are still good breakers. The laws of physics haven't changed in a few years. LOL.
Is the panel overloaded? Does the main trip often? If not probably not.
Is there room on the bus bars for what you would like to add in the way of circuits, breakers? Yes your likely OK. No? Might still be your OK.
Circuits can be sometimes be combined to free up space. You don't want to combine required circuits, kitchen, bath, laundry or dedicated or heavily loaded circuits like a computer circuit or a shop circuit.
Bedroom circuits and most lighting circuits are good candidates. Some times I will map out all the circuits and combine what I think are circuits which are not near capacity. A good clamp type ammeter helps. A good check is to combine the circuits and turn on everything, within reason so save the blow driers, on both circuits. Let it run for a half hour or so. This is a good time to beak out the ammeter to be sure the breaker isn't malfunctioning. If it holds, and the ammeter says it should, your all set.
Doesn't solve the entire problem but it is a start. Getting pushamatic breakers can be an issue. Look in big box hardware stores, small family hardwares and local supply houses for what you need. Older and less used breakers are a regional thing.
Once you get the breaker you need install it in the spot/s you have opened up. Now the real question. With your new circuit in place will the main hold? Interesting enough new circuits, even ones that are fully loaded, seldom add as much to the panel as the new load.
Adding a 20A shop circuit doesn't often add a full 20A. While your in the shop working the new circuit your unlikely, unless your one who runs everything at once, to be in the living room working the plasma TV or in the bathroom running a blowdrier.
More often than not if the main is not very close to maximum capacity, check with an ammeter, adding another circuit works out. No guarantee but those are the odds.
Worse case it doesn't work out and you have to upgrade the panel and feed from the meter. That is, of course, the alternative. Often one involving many coins. Trying to stretch the existing panel takes time and risks the price, and trouble, of getting an obsolete breaker. If a contractor that does a lot of old and service work in your area tries to stretch the panel they will likely have the breaker so a failure won't cost more than the lost time.
I mention this seemingly inconsequential cost of an obsolete breaker because these units can, some sizes and brands, involve substantial amounts of cash.
If you do it yourself or in concert with a helpful electrician your out a daughter, son or beer, depends what he's into and maybe the trouble of burying the body or perhaps just your own time if your handy.
Replacing the panel, feed and possibly the meter and riser or mast still remains an option.
Sounds like he may have the old Pushmatics - just like I do in a '60s meter/main with 100A cartridge fuses on the disconnect. Hard to find.New version Pushmatics were over at Home Depot (behind glass) but they have a stab on the back and won't fit my old bus bars. It has been suggested that you just grind down the stab. I had e/mail with the factory and bought some from a guy in Michigan who was demoing a cabin.The ToolBear
"Never met a man who couldn't teach me something." Anon.
It is possible your house was a one-off, a singular instance in your area using pushamatics. More likely there are clusters of homes who have the same panels. Tends to go that way.I recommend you call round to electrical contractors and supply houses in your area. Start with the electrical supply houses as they can recommend the sort of contractors your looking for. Generally speaking the breakers you need will likely be available either new or rebuilt at one or more supply houses. Rebuilt is OK. Just be sure to check the guarantee.If the supply houses are out ask which contractors do the most service work and renovations. Typically some contractors do mostly new construction. They won't do you much good. You want a contractor who deals with older houses and panels. When I did/do service work I typically have a wide selection of used breakers on hand. Odds are at least one service truck in your are has what you want on board.As I outlined sometimes there is no alternative to upgrading to a larger panel and/or service. When the old panel is taken out the contractor typically takes the old panel and breaker with him. Not like it will do the HO much good and most are happy to have one less thing to throw out. Typically these old breakers are stored, cleaned up a bit and reused as needed. Nothing wrong with this as the breakers are guaranteed the same as new breakers, 90 days. These contractors will typically have limited supplies of spare breakers on hand. Give them a call. Explain the situation. Cut a deal and be sure to ask about the guarantee. Most will give you the full 90 days.Pushamatics have a decent reputation IMHO. If this was a Federal Pacific, XO or Zinsco panels, all obsolete by at least 40 years, I would be more inclined to replacing it as these are IMHO more trouble than they are worth. They were marginal when they were new. I have seen all of these fail both open, not a big problem but you lose power, and closed, a big problem as the breaker no longer protects the wiring while the power is still on and the HO unaware of a problem. The worse of all possible failure modes.
"Pushamatics have a decent reputation IMHO. If this was a Federal Pacific, XO or Zinsco panels, all obsolete by at least 40 years, I would be more inclined to replacing it as these are IMHO more trouble than they are worth. They were marginal when they were new. "
Yes, friends don't let friends buy Zinsco. I have some experience of them in office remodels. Yeech.
Thanks for the info. I am glad I bought all the Pushmatics in that panel in Michigan, so I have some backstock in common 1P, 2P units. Just what I need when I push and it doesn't matic back. Suspect that nowadays you could find them on eBay.
Guess you don't recommend grinding the stab off the new ones. Aside from that, they would fit. Wonder why they added it.
The ToolBear
"Never met a man who couldn't teach me something." Anon.
Here is the chart to calculate the actual load.
Now for fixed equipment on their own circuit AC, refigerator , furnace, etc. use the nameplate current rating not the circuit breaker size.
Bill, I do not see the chart.
Sorry forgot to post the link.http://www.taunton.com/finehomebuilding/pages/bh0019.asp