[Archived]

The primary 12V loads will be lights and DDEC on later models. I don’t remember what year they made the switch, but early models had 24V lighting except for headlights. Regardless the 12V side is not heavily loaded. The 24V side has heavy draws such as the starter, the coach OTR fans, etc.

[Corey]

You are right Bob, it was a seated coach. No dash light on before or ever. I did check the voltage at the equalizer and it did read correct voltage. My voltage gauge on the Dash reads 28 volts. I know it has an adjustable voltage regulator above the batteries, not sure if it has been tampered with by previous mechanic from Western Star dealer.

[Archived]

Inverters to engine batteries….No add some house batteries…

[Archived]

Jeff, That was what I were thinking from reading articles online. I am home building this bus from scratch so I have the luxury of designing the systems that fit my use and work best. Can I build a battery bank for the 5000 watt inverter and run wires in parallel to one 12 volt chassis battery to take advantage of recharging house battery? My plan is to only use inverter while engine is running until I can save up for a 15kw diesel generator. I will either be using shore power while parked or inverter power traveling. I’m looking at only using lights, TV and refrig while traveling. I’ve got to read up on my inverter to find out the correct size fuse to use between the battery and inverter. I read online someone suggested a 150 amp fuse inline. Sounds a little to large to me seeing how I only use 50 amp service on shore power. Any ideas that will help are greatly appreciated! Thanks Mike

[glen]

Mike,

This is a suggestion. Set up the electrical systems (chassis and house) so they are independent of one another. I suspect you have a single 50DN alternator that is 24 volts. You will have to add a dedicated 12V alternator if you intend to use a 12V house system for house battery charging.

The inverter(s) are only going to function as house battery charger(s) when powered by shore or generator power, otherwise the 12V alternator is going to be the charging system.

You would do yourself a huge favor if you design the electrical system to be similar to the systems installed by the professional converters. They are robust, safe, easy to use, reliable and simple.

[Archived]

Jon, That’s an excellent idea adding a additional alternator and seperating the two. Thanks for the advice! I am wondering what size alternator and add on kit to buy or where to even buy one?

[Fred F.]

The answer is not cut and dried. Most conversions that have two alternators size them based on whether they have OTR or are running house AC units while driving.

In the case of a coach without OTR using roof airs for example while driving the 50DN is usually a 12 v olt model with 270 to 300 amp output. The chassis would use a 24V alternator, often in the 140 to 150 amp range.

If the coach uses OTR the 50DN remains as a 24V alternator to handle the heavy loads of the condenser and evaporator fans, and the house gets a 140 amp 12 volt alternator. House AC units in that case are run from shore or generator power.

There are variations of the above but how your systems are set up is going to determine your choice of alternators.

There is another consideration. Make the house 24 volts, use the existing 50DN, add a means of isolating the house and chassis battery banks, and set up the house batteries with an equalizer like the chassis to handle 12 V loads like the dash radio.

[Doug]

amps X volts = Watts 2500watt divided by volts(120)= 20 amps in perfect world more like 18 available. you can figure input to unit same way. 150 amp alt x 12 volt =1800 watts… hope this helps.