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I made some progress on the coach today. The electrical system is so overcomplicated that I will have to include owner's manual and service manual supplements if I ever sell it. Most of these ideas come from my experience with airline electrical systems.
Sorry some of the pictures are blurred. Also, the wires that are hanging loose everywhere will be neatly bundled when the project is finished. They're still waiting to be hooked up.
The battery compartment contains two large, deep-cycle marine batteries. They are cabled in parallel, directly to the inverter, and back from the alternator through a trailer diode. In the middle of the cable from the trailer diode is a bus tie relay, whose function I will explain later. A 10-gauge wire feeds power back to the circuit breaker panel in the dash.
Here is the bus tie control panel. Its purpose is to allow me to disconnect the two rear batteries from the alternator when the system load is high, thus preventing overheating of the alternator. I might put in an alternator temp gauge, but for now, the voltmeters are a good measure.
There are four possible combinations:
1.) Key off, bus tie switch off, meters show nothing.
2.) Key off, bus tie switch on. Right meter shows the voltage at the rear batteries.
3.) Key on, bus tie off. All of the accessories can still be run from the rear batteries, but only the original battery and critical systems like wipers and lights are online.
4.) Key on, bus tie on. The alternator is charging all three batteries, and everything is online at 13.5 volts.
The reason for this system is to allow me to run accessories such as the radios, interior lights, power outlet, casket table, inverter, etc. without draining the main battery. If the rear batteries go dead, I can still start the engine and charge them.
Here is a shot of all three panels. I'm going to remove that ugly vinyl from the breaker panel and recover it with cloth to match the ones next to it. The great thing about the breaker panel is that all you have to do to work on it is remove one screw and slide it out. You can even do it while the engine is running. If you're troubleshooting, or if you want to leave the doors open but you don't want the interior lights to come on, you just pull or switch the breaker off. No crawling around under the dash.
In the breaker panel, the top row is for accessories that are unswitched (run with the key off). The first breaker switch is for the interior lighting relay and the gasper fans (they move air from the cabin to cool the rack underneath the mound, and circulate air throughout the interior). The next switch is the radio master, for the stereo and CB. I'm going to add one more breaker for the power outlet, which will go where that old voltmeter is now.
The lower row is for accessories that are powered from the rear batteries, but run only when the key is on. The first breaker is for the power windows, and the other one is for the A/C compressor and electric fans. The big white breaker is a 70-amp feed from the rear batteries to the panel. I plan on adding a few other things later on.
The two paddle switches turn on the electric fans and A/C compressor. That's simple enough.
The other two switches are a little more complicated. One of them turns on the interior lighting, and has three positions, on-off-auto. If you put the switch in the "auto" position, the lights will only come on when a door is open. The other switch is for the gasper fans, and it has three positions, low-high-off. If a door is opened and one of these two switches is "on", a buzzer will sound. You have a few options to shut off the buzzer...either close the door, turn the switch off, turn the light switch to "auto", or pull the circuit breaker. I built the system and strung it out on the floor in my living room to test it, but I still have to hook everything up in the coach.
A whole bunch is done, a whole bunch is left to do, and I may never be totally finished with it because I will always come up with some hare-brained idea to upgrade it. It is very easy to upgrade, though, just drill another hole in the panel, add a circuit breaker, and you've got power.
-denise
Sorry some of the pictures are blurred. Also, the wires that are hanging loose everywhere will be neatly bundled when the project is finished. They're still waiting to be hooked up.
The battery compartment contains two large, deep-cycle marine batteries. They are cabled in parallel, directly to the inverter, and back from the alternator through a trailer diode. In the middle of the cable from the trailer diode is a bus tie relay, whose function I will explain later. A 10-gauge wire feeds power back to the circuit breaker panel in the dash.
Here is the bus tie control panel. Its purpose is to allow me to disconnect the two rear batteries from the alternator when the system load is high, thus preventing overheating of the alternator. I might put in an alternator temp gauge, but for now, the voltmeters are a good measure.
There are four possible combinations:
1.) Key off, bus tie switch off, meters show nothing.
2.) Key off, bus tie switch on. Right meter shows the voltage at the rear batteries.
3.) Key on, bus tie off. All of the accessories can still be run from the rear batteries, but only the original battery and critical systems like wipers and lights are online.
4.) Key on, bus tie on. The alternator is charging all three batteries, and everything is online at 13.5 volts.
The reason for this system is to allow me to run accessories such as the radios, interior lights, power outlet, casket table, inverter, etc. without draining the main battery. If the rear batteries go dead, I can still start the engine and charge them.
Here is a shot of all three panels. I'm going to remove that ugly vinyl from the breaker panel and recover it with cloth to match the ones next to it. The great thing about the breaker panel is that all you have to do to work on it is remove one screw and slide it out. You can even do it while the engine is running. If you're troubleshooting, or if you want to leave the doors open but you don't want the interior lights to come on, you just pull or switch the breaker off. No crawling around under the dash.
In the breaker panel, the top row is for accessories that are unswitched (run with the key off). The first breaker switch is for the interior lighting relay and the gasper fans (they move air from the cabin to cool the rack underneath the mound, and circulate air throughout the interior). The next switch is the radio master, for the stereo and CB. I'm going to add one more breaker for the power outlet, which will go where that old voltmeter is now.
The lower row is for accessories that are powered from the rear batteries, but run only when the key is on. The first breaker is for the power windows, and the other one is for the A/C compressor and electric fans. The big white breaker is a 70-amp feed from the rear batteries to the panel. I plan on adding a few other things later on.
The two paddle switches turn on the electric fans and A/C compressor. That's simple enough.
The other two switches are a little more complicated. One of them turns on the interior lighting, and has three positions, on-off-auto. If you put the switch in the "auto" position, the lights will only come on when a door is open. The other switch is for the gasper fans, and it has three positions, low-high-off. If a door is opened and one of these two switches is "on", a buzzer will sound. You have a few options to shut off the buzzer...either close the door, turn the switch off, turn the light switch to "auto", or pull the circuit breaker. I built the system and strung it out on the floor in my living room to test it, but I still have to hook everything up in the coach.
A whole bunch is done, a whole bunch is left to do, and I may never be totally finished with it because I will always come up with some hare-brained idea to upgrade it. It is very easy to upgrade, though, just drill another hole in the panel, add a circuit breaker, and you've got power.
-denise
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