Mounting 1500 Watt Invertor

MACHZER wrote:
I was thinking going to 3000 watts but the cable requirements must be outstanding and a quick battery killer for sure!

epfd217 wrote:
Someone above posted info about the loads used by a toaster and coffee maker. Most small microwaves are 900 watts (higher than the toaster reference). Hopefully you've got a pair of batteries to provide the juice.

I have zero interest in running a microwave oven with an inverter but I am nonetheless quite aware just how severely any inverter can suffer excessive voltage drop under heavy load sufficient to cause it to trigger it's LUP alarm and eventually shut down completely. :M Even with appropriate wiring I'd bet a 1500 watt inverter would be considered marginal for this application, especially if powering it with just 2 GC-2s which would draw down very quickly under such a heavy load. The OP hasn't defined just which type of 1500 watt inverter he has, MSW or PSW - but if it's the former any appliance with a clocking device is unlikely to work properly. :( A PSW inverter will solve this issue but in higher rated sizes at considerable cost ... personally I don't see the ROI just for the convenience of being able to occasionally run a microwave oven. To each his / her own I guess. ;)

MACHZER wrote:

I was thinking going to 3000 watts but the cable requirements must be outstanding and a quick battery killer for sure!

This statement shows you don't understand how the inverter and battery bank work. You should check out "12 volt side of life" and Handibob's blog for info about using 12v power.

Someone above posted info about the loads used by a toaster and coffee maker. Most small microwaves are 900 watts (higher than the toaster reference). Hopefully you've got a pair of batteries to provide the juice.

MACHZER wrote:
Where did you mount yours? Did you run the large cables well into your trailer or did you mount external and run a 115V power cord?

I am thinking about mounting inside the front storage compartment which is close to the outside batteries and then run a 115v line internal from there.

Using an inverter to power heavy draw devices such as a microwave makes little sense to me so I instead installed a 1000 watt PSW inverter on a shelf in our trailer's front pass through storage compartment and wired the output to dedicated receptacles - one outside, duplex receptacles on each side of the bed, and a third at the galley. We use it primarily when we've lost campsite power but still would like to use the coffee maker, toaster, a few fans, and my wife's hair dryer. Since this inverter typically draws no more than 60 amps with these types of loads 6' of 4 gauge cable is well within spec, avoiding the need for anything heavier. With a single G27 the inverter will run the coffee maker (550 watts) just fine but does struggle with the toaster (750 watts), eventually causing the inverter's low voltage warning to alarm. Upgrading to a pair of G31s or GC-2s would solve that issue but since we don't dry camp often I view this as a poor ROI. Instead, if I load support the trailer battery (4 pics) with the truck (running) voltage drop under heavy load is far less and the inverter doesn't come anywhere near close to low voltage alarm. I wouldn't consider this a solution for those who always dry camp but for occasional use load support works really well for moderate loads under 1000 watts. Pics are in my gallery if you're interested. :)

If you have typical battery set up on the tongue of the trailer, mounting the inverter as close as possible in the front compartment is ideal. Check the installation instructions of your inverter and use the recommended cables and fuse to connect to the batteries. I think you'll find that you will be using 1/0 cable and a 120 amp fuse.

Microwave and hair dryer are big loads, it will challenge a 1500 W inverter with typical battery bank. The hair dryer or coffee maker will be OK, as will any entertainment devices.

FWIW, I run a small 120 V refrigerator and a few 120 V entertainment devices, along with all the cabin loads using a 1000W Xantrex PS inverter. I have 300 AH of battery capacity in two banks of batteries. I also have solar charging that helps during the day.

My 12V loads are small, only some LED lighting and occasional water pump and fans. My alarms are all battery powered and I don't have any other standby loads. My "furnace" doesn't use a fan/blower.

I just dedicated a few receptacles for 120av inverter use and my inverter has 5V USB outlets for charging phones.

I added a 600WATT PSW Power Inverter to my off-road POPUP setup. It is about 5-feet away from the battery terminals... I run two drop cords from the Power Inverter that has multiple 120VAC receptacles on it with one at the home entertainment center area and the other one going back to the bedroom nite stand area.

When camping off-grid we usually end using around 300WATTs worth of 120VAC connections... I also have the 1500WATT unit but never use it...

Roy Ken

Thanks for the responses,

I will mount in the front storage. I just need for the nights of parking lot overnight stays for a quick micro or low hairdryer in the morns.
I was thinking going to 3000 watts but the cable requirements must be outstanding and a quick battery killer for sure!

Your plan is similar to what I did with mine. I mounted the inverter in my front storage compartment, and ran 4ga power cable to the battery in a fairly short (approximately 2-2.5') run. As donn0128 said, don't skip the fuse or breaker on the positive cable, close to the battery.

Don't under-estimate the power draw of a microwave. Even if your inverter can handle it, your battery bank likely won't for long.

Mount as close to the batteries as possible. Dont forget a fuse or breaker between batteries and inverter. I mounted mine on a wall maybe 18 inches from the batteries and ran two dedicated 120VAC circuits directly from the inverter to dedicated receptacle behind the TV. I labled each system with where it gets power from. To me this was simpler and far cheaper than trying to tie the whole house into an inverter and buying a transfer switch.