By Bryan Martin, contributing columnist
Who wouldn’t like to occasionally operate a Shop Vac, a heat gun, or Lord knows what else from your truck? Well, to do this you will need to add a power inverter. We field a lot of inverter questions here at CSM, and also get the opportunity to correct a few poor installs from time to time.
Two of the most common mistakes are buying an inverter that is too small to do the job and installing it with small cables without putting a fuse in the positive cable.
Let’s start with the obvious question: How big of an inverter do you need? That depends on what type of equipment you want to operate. If you are only in need of a laptop, a 19-inch television, a battery charger for a cordless tool, or items like a glue gun or a printer, a simple 400- to 800-watt unit should be just fine. These are fairly inexpensive units (well under $100) and are plug-and-play as far as the install. Grab one at the truck stop and make it happen.
For bigger electronics such as a refrigerator, microwave, hair dryer, 26-inch television, a toaster or a Skilsaw – you will need a 1,500- to 2,500-watt inverter. My suggestion is that if you can budget for the 2,500-watt unit, go for it. You’ll have adequate power to run a couple of items at the same time, and the likelihood of “stressing” out your inverter is minimal. Typical cost on a 1,500-watt inverter is $150 to $190, and a 2,500-watt goes for $239 to $299.
There are dozens of inverter manufacturers. Buy one with a name you recognize or do some legwork on the Internet and check out the reviews of ones you’re interested in.
Installation – pay attention; this is important. A 1,500-watt inverter needs a No. 4 gauge power and ground cable. A 2,500-watt needs twice that. So, on a 2,500-watt installation use a No. 2 cable to make sure you are getting sufficient battery voltage to aid in extending the life of your inverter. You can also double up the No. 4 gauge cables. Use two No. 4 power cables and two No. 4 ground cables.
Regardless of the wattage, if your inverter is more than 15 feet from the batteries, use No. 2 cables or the doubled No. 4 cables.
It is also imperative to install a 100-amp fuse or a 150-amp circuit breaker in the positive cabling. If you are wondering where to buy a 100-amp fuse, try the car stereo shops; they always seem to have them available.
Install the fuse as close to the batteries as possible. In the event of a short circuit, the fuse will blow and minimize the risk of heat or fire. The advantage of a circuit breaker over a fuse is the circuit breaker will reset and continue operation once you have repaired the short. The fuse will need replacing after shorting out.
Most inverters are mounted in a sleeper luggage compartment or under the bed. Use caution when routing your positive cable. Be sure to use extra insulation if it’s potentially coming in contact with a potential sharp edge. Make sure air can flow all around the inverter. These units are air-cooled and can’t be boxed in a corner or have items thrown on top of them.
When you get lucky and have two or three days off work, it will be necessary to shut off the inverter to keep from slowly draining your truck batteries. Even though there will be no appliances being operated, your inverter is still busy supplying 110-volt power, just in case you need it. Cobra offers a handy remote switch that can be conveniently mounted in the sleeper for easy operation.
I know, I know, you’re thinking “Why in the world would I wanna use a Skilsaw or a heat gun from my truck?” Truth is, you may never have the need. But one thing is for sure: A coffee pot would dang sure be nice. So what are ya waitin’ for? Make plans to get powered up and you’ll be ready to enjoy most of the household amenities right there in your highway Hilton. LL