Sunday, January 16, 2011

110-Volt AC Electrical System

The electrical system in your Lazy Daze is a little more complicated than that of your home. Basically there are two major systems in your LD: a 110-volt AC system that is similar to your house and a 12-volt system that provides power when you are not plugged into the electrical grid, either at home or in a campground. The 12-volt system allows you to boondock without utility hookups and enjoy most of the conveniences of home. 

Sources of 110-volt power
The addition of a generator, standard now for quite a few years on Lazy Daze motorhomes, allows you to live just as you would at home, by providing 110-volt power on-demand. With the generator, you can enjoy your air-conditioner and operate the microwave oven.

At locations where electrical hookups are available, a 30 amp extension cord may be connected to the RV, providing 110-volt service.

A third way to provide 110-volt power is through the use of expanded battery capacity, additional solar panels and 12-volt to 110-volt inverters. These inverters can range from small units that plug into a 12-volt plug to large, "whole-house" inverters. The smaller inverters can run smaller appliances, while the larger ones will let you briefly use the microwave.

The heart of a standard 110-volt system is in the converter/charger that is a standard accessory of all LD's. As it name implies, the converter/charger unit contains a converter that changes 110-volt AC power to 12-volt DC current.  It also contains a charger for your house batteries. It includes a small panel with three 110-volt AC circuit breakers.  Mounted on the back of the converter is an automatic transfer switch (ATS) which automatically cuts out the shore-power circuit when the generator is operating. This prevents dangerous feedback of power into the electric grid.

Surge Protector
A highly recommended addition to the 110-volt circuitry is a surge protector, which can help protect the system and attached equipment from sudden and dangerous variations in power. Campground electric hookups are notorious for having wiring problems; a surge protector is invaluable.

There are two basic types of surge protectors: permanently hard-wired or portable units. The hard-wired models are preferred by many, for it is always there to protect your LD. You will have to plug a portable model into the campground utility post and you should lock it in place to prevent theft.

It is also advised that you carry a small plug-in circuit tester and use it every time before you plug in the LD's power cord.

Routine Maintenance
Keeping in mind that all this wiring is in a mobile home bouncing down the highway, a little preventive maintenance could prevent a dangerous fire from occurring.  Vibrations can loosen connections.  What can then happen is that a loose connection starts arcing and actually turns into a "welder" all without drawing enough amps to trip the breaker on the loose wire. The "Buss" bar(s) and wires get cherry red hot and can actually distort and melt. This overheating can easily start a fire in the motor home. If it happens while you are plugged in or have the gen/set on while you are outside or away, it can be a disaster.

It only takes a few minutes if you choose to check your wiring yourself. First, turn off or disconnect any sources of 1100volt power.  Next, remove two screws that secure the AC panel cover that's to the left of the 12 volt DC distribution panel (fuse panel). This exposes the circuit breaker bodies and associated wiring.  In the AC portion of the panel, there are normally 3 colors of wires. A "Romex" cable contains each of these 3 wire colors and most often has an ivory or off white jacket. Of these 3 wires, Ground will be bare copper (or rarely, green), Neutral will be white, and Hot will be black.

There will be a couple of terminal strips, one for ground wires and one for neutral. The hot, or black wires will be attached to the circuit breakers - - these are the screws that can be exciting to tighten, but only if you don't use caution, an insulated screwdriver (most are), or you choose not to disconnect shore power, turn of the gen-set and/or whole house inverter. Turning off the individual circuit breakers will also serve to remove power from the output screw terminals. Be safe and do not to allow the screwdriver blade to touch you or any nearby metal when it is touching the circuit breaker screws.

Once you are looking at the screws that hold the wires in place, check each and tighten as needed. 

Caution: Be sure to shut off all sources of power before opening the converter.
There are photos of the AC Panel Meltdown, and photos and instructions for making this simple but critical test and correction on "Techsnoz" in the "Files" Section. See Article 36.
Contributors: Noel & Jackie, bumper, Terry Tanner
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