Cable and fuses for Magnum MSH 3012 M inverter

I use these bolt on fuses
I also have CB master disconnect switches. I don't know if Eaton-bussmann offers them for sale but a four position battery master was rated at 315 amps. I think the Blue Sea master switches are rated to 300 amps.

Our microwave pulls around 180A on the 2012

PT- the 200ma draw is inverter Off. Dunno what it is when inverter is On since I have things like the DTV Rx and TV's that pull idle current (the Direct Rx somewhere around 50w). I've never looked at inverter idle current with the house disconnected but 2a to keep the FET's On may be accurate.

smkettner thanks the microwave will be largest draw so properly ok can hit the button and disconnect that way from batterys. I do intend to get the remote start and stop so no need to run when not used and have changed lights to LED.

Slownsy wrote:
Thanks again. will a ADSRO 12V DC 250AMP circuit breaker be ok instead of the type T fuse.I also think I have seen a fuse connected directly of battery?
Frank

250 amp CB might trip near max power or during start surge of a 3012.
If you are not really running at max you should be fine. Microwave is about 160 amps.

Hi Jeff,

Others have said 2 amps for idle. I agree about having a disconnect.

SCVJeff wrote:
The Magnum is kind of an idle current pig. The MS-2012 draws somewhere around 200ma IIRC.

I added a big marine disconnect after watching a friend bolt out the door in Quartzsite heading to the storage bag after his Zantrex filled the coach with smoke and the only way to kill it was with a wrench and 3-5mins. This is an emergency kill swx, not one to remove parasitic loads tho

The Magnum is kind of an idle current pig. The MS-2012 draws somewhere around 200ma IIRC.

I added a big marine disconnect after watching a friend bolt out the door in Quartzsite heading to the storage bag after his Zantrex filled the coach with smoke and the only way to kill it was with a wrench and 3-5mins. This is an emergency kill swx, not one to remove parasitic loads tho

Thanks again. will a ADSRO 12V DC 250AMP circuit breaker be ok instead of the type T fuse.I also think I have seen a fuse connected directly of battery?
Frank

Slownsy wrote:
Hi all I finally got the inverter and Magnum calls for 4/0 cable 405A max fuse classT or equivalent as this has a time delay however because the fuse can be energized from both directions has to be able to disconnect power on both ends ? They picture a battery disconnect on inverter side of fuse nothing on battery side Do,they disconnect positive cable ?. I have already got a trimatic display and the 500A shunt for negative. I intend to order cables ready made and also fuse and disconnect and then have a mobile technician help with install. Any recommendations for switch and fuse appreciated. There is also some recommendations as regards to use of GFCI. Is this referring to the power points?. In Australia we use RCD relays Residual current devise but in RV also RVD as no earth stake if this makes any sense to anyone comments appreciated. We will also have a step down transformer instaled for use in Australia as we intend taking it back. Any recommendations as for good technician in Fort Myers, Naples etc FL. Thanks.
Frank

As to a Battery disconnect. I HAVE NEVER SEEN A RV INVERTER/CHARGER WITH A BATTERY DISCONNECT INSTALLED FOR THE INVERTER BATTERY CABLE CIRCUIT. There is NO need unless you want to be able to positively disconnect the Batteries to keep from draining them. But, turning the Inverter OFF will stop parasitic drains. So, as I stated no need for a battery disconnect. The 200/250/300 amp fuse on the Positive cable is a protection for the cable from the batteries in case of short. NOT a protection from the Inverter to the batteries. You want that fuse as close to the Batteries as possible. Doug

I do the catastrophic failure fuse at the battery banks. 350 for each set of cables (two banks).

I use the fuse as the disconnect. You don't need another 300 amp connection for a switch that will be rarely used.
I would go a bit tight on the Class-T with maybe 300 amps max as it will pass quite a bit more current for an extended period.