Gas detector install

[fireman24]

Hi, I am replacing my LP das detector. The one installed does not work, and I ordered a similar model. Its a safe-t-alert 40-442A. The old detector had only a red and black wire,the new is the same. The unit works off of 12V. I dont have diagram & dont want to guess with the power system in the trailer. My question is on the power supply are there 2 systems? 120V for the lights and outlets. Then a seperate system for 12V like the gas detector? Now how do I tell them appart? I want to install this the right way and not fry the new detector. Any help would be great. Thanks.

[dthurk]

The two systems are separate.  How to tell them apart...if you're not plugged in to 110 with your shore power cord and it works, then it's 12 volt.  If it doesn't work, it's 110.  

Your propane detector is 12 volt.  Your new propane detector, if it's similar to the old one, would also be 12 volt.  I haven't seen one "out of the box", but there must be some color coded leads or marked terminals on it if one terminal is positive and the other is negative.  If they're unmarked, usually you can hook them up either way.  Is there a manual with installation instructions?   That usually can shed some light on the situation.

[tlhdoc]

There are 2 electrical systems.  The 110 volt, AC power only powers your electrical outlets (like at home) and the power converter.  The power converter, converts 110 AC power into 12 volt DC power, so that your lights, water pump, furnace, propane detector will work, when the camper is plugged in.  The 12 volt system also works off of your battery if you have one.  As long as it is a 12 volt detector you are all set just hooking it up like the old one was.