Need a small breaker panel to finish Inverter Replacement

Just curious which Maganasine you are installiing. I'm working on installing a MSH3012. Good luck with your install.

westend wrote:


An alternative is to buy surface mount breakers and wire up the distribution from those. You can make it all look good by mounting the breakers on a piece of aluminum plate. Here's a good place to shop for circuit protection: Waytek Wire. Mounting three surface mount breakers will use about 1/8 -> 1/4 the space of a steel box. If you'll pay the price, the Cooper-Bussmann manual breakers are the way to go, they even sell a sealed Marine type (not necessary, IMO).

Do they make surface mount breakers for 120 AC current? Everything I looked at was automotive, mostly @12 volt.

KD4UPL wrote:
You don't need a main. Your main between your power cord and inverter protects on shore power. Your inverter shut down circuits protect on inverter power. Is your inverter even capable of enough power to trip a 30A breaker?
If you really want one then get a 2 space breaker panel like the many that have been shown in this thread, install a "main" 30 in one slot and a tandem 20 in the other. Then wire the output of the main to the input lug of the other buss bar holding the tandem.

From the diagram the OP posted, the inverter was fed from the shore power breaker panel with a 30A single pole breaker.

That would mean that the input of the inverter acts as a 30A "UPS" and would have 10 ga wire from the RV breaker panel.

The output of the inverter (which acts like a ATS) was sending power to TWO different 20A circuits.

IF the OP does not add a small breaker panel to the output of the inverter (IE tie the two circuits together) and the output of the inverter does not exceed 20A (2400W) then the OP will need to DOWN GRADE the 30A breaker. The reason for that is the two 20A circuits from the inverter would be serviced with 12Ga wiring..

OP simply needs a small add on breaker panel, the smallest are "2 space" FOUR circuit boxes which can handle one double pole or 2 single pole standard size or 4 half size single pole breakers..

These panels do not have "main" breakers, instead they have INPUT LUGS.. Cost shouldn't be much more than $12 for the small panel..

Looks like this..



This one is 11" tall and 6" wide..

Found HERE

Takes standard easy to find breakers (but if you use two standard single pole breakers you will need to "jumper" the two lugs feeding the breakers from the inverter together).

Best bet is to go to the store and see what they have available, many times they have other versions than what is listed on the website. You might wish to check Lowes also if the panel at Home Depot is too large.

IF new panel will not fit where the old inverter was you can move the location of the new small breaker panel by using 10 ga wire from the inverter to the new breaker panel location.. That keeps things inline with the 30A breaker feeding the inverter.

BLUE SEA PRODUCTS may have a small Marine Boat type circuit breaker for you... Might fit your needs better than the commercial wiring stuff...

Search on Internet... Buy from AMAZON

Roy Ken

You don't need a main. Your main between your power cord and inverter protects on shore power. Your inverter shut down circuits protect on inverter power. Is your inverter even capable of enough power to trip a 30A breaker?
If you really want one then get a 2 space breaker panel like the many that have been shown in this thread, install a "main" 30 in one slot and a tandem 20 in the other. Then wire the output of the main to the input lug of the other buss bar holding the tandem.

I bought this same one for mine.

http://www.ebay.com/itm/NEW-EATON-Main-Lug-Load-Center-40AMPS-MAX-120V-AC-CA-BLK-RV-MOTORHOME-HOT-TUB-/232146891694?hash=item360d0873ae:g:B0EAAOSwA3dYLkMx

DrewE wrote:
(If it's running on inverter power, and not pass through, then presumably the inverter's protection circuits would limit current by shutting down.)

x2

bigbillsd wrote:

time2roll wrote:
You do not need a main as shown in the picture.

If there is no main, what would protect the inverter from both circuits pulling 20amps and overheating the 30amp circuit to the inverter? I understand that scenario probably shouldn't happen, But..

The 30 amp should trip before it overheats.

The big-box home improvement stores have service disconnect boxes and small load centers. They sometimes clearance them because sales are low. I bought my last 75 amp load center for around $25, IIRC.

An alternative is to buy surface mount breakers and wire up the distribution from those. You can make it all look good by mounting the breakers on a piece of aluminum plate. Here's a good place to shop for circuit protection: Waytek Wire. Mounting three surface mount breakers will use about 1/8 -> 1/4 the space of a steel box. If you'll pay the price, the Cooper-Bussmann manual breakers are the way to go, they even sell a sealed Marine type (not necessary, IMO).

bigbillsd wrote:

time2roll wrote:
You do not need a main as shown in the picture.

If there is no main, what would protect the inverter from both circuits pulling 20amps and overheating the 30amp circuit to the inverter? I understand that scenario probably shouldn't happen, But..

The 30A breaker in the main RV panel that feeds the inverter does precisely this. That breaker is needed; a main breaker for the subpanel is superfluous. (If it's running on inverter power, and not pass through, then presumably the inverter's protection circuits would limit current by shutting down.) If one's still worried, use 8 gauge wire rather than 10 gauge wire between the inverter and the subpanel and it won't be overloaded even if 40A is flowing.