Forum Discussion
travelnutz
Sep 04, 2013Explorer II
We've been using hard wired installed MSW inverters for our 4 cabined boats since 1985 and in our 7 RV's since 1989. We are very well versed and experienced with inverters and their usage and how long they will run until the battery voltage drops to the 10.2V or 10.5V and the inverters will auto shut down!
The hard wired inverters were from 750 watts to 2500 watts in size. The 750 to 1500 watt inverters had 3 group 31 deepcycle batteries and the 2000 and 2500 watt inverters have 7 of the same batteries in their banks. Also have 4 smaller inverters not hard wired from 300 watts to 500 watts in size. They are a wonderful source of silent 110 AC even thought we also have gas or propane fueled generators too. Generators make noise but inverters don't! They are perfect for at night TV, microwave, puter, etc or in the early morning for coffee, toast, TV, microwave, etc when no noise is wanted ever. DO NOT use an inverter for a hairdryer as it alone takes all a 2000 watt inverter can handle and will drain a battery bank real fast down to auto shutdown. As a battery's voltage drops from 12.6V the amperage draw to produce 110 AC wattage needed increases which hastens the discharge drasticly .
Example: a microwave using 1000 watts AC usually will only be running for a minute or so and the same for a toaster and most coffemakers draw 900 watts or less and run for 3-4 minutes depending on size and brand. A hair dryer however draws around 1875 watts and will be running for 5 to 10 minutes per person's use. 2 people drying their hair for 10 minutes will draw a bank of 3 group 31 deepcycle 205 minute reserve 12V batteries down to 50% as we know so well and learned NOT to do it. Wait until you can use the generator if you must use a hairdryer.
If you are hooking your inverter to the shore power AC input on your RV, you are going to be running your converter which is not needed all the time the inverter is turned on and a normal RV converter draws between 350 and 500 watts of 110 AC as it's also trying to recharge your batteries too. So you'll need a 2500 watt inverter to have even 1875 watts (15 amps) of AC usable from the RV outlets. In other words, you are wasting your battery reserve amps running the converter for nothing! To avoid this waste there's 2 ways:
1. Install a 25-30 amp relay activated by the turned on inverter to cut the AC going to your converter before the turned on inverter is plugged into the RV shorepower connection/cord.
OR
2. "I learned to do it this way". In the TT's and 5th wheels I mount the inverter in a storage area and use a remote control. $30 tops! Then ran two new 15 amp AC circuits by running two #14 household AC wire thru the basement etc of the RV and added an outlet next to the exiting RV AC outlet in the bedroom and bathroom on one 15 amp circuit in the living room and one in the kitchen on the other new 15 amp circuit. Thus, the inverter has absolutely nothing to do with the RV OEM wiring or converter and can't be shorted out or cross wired and so convenient. Merely have to move an appliance plug from the RV circuit outlet to the inverter outlet for power. How hard is that and our batteries thank us and reward us with more than double the voltage charge reserve life. The TT's and the 5th wheels have 5-7 batteries in their banks.
I did one truck camper this same way with a seperate wired circuit but found that it's just as easy to have a 6 outlet strip screwed to the wall and always plugged in to the inverter since the interior space is so much smaller. In a TC, the inverter is right on the wall under the fridge or on the side of the front step covering the fresh water tank. Simply turn on the inverter and plug into the strip and have AC anytime anywhere. Fridge auto switches over to gas as does the waterheater anyway. One battery is in the TC battery comparment and 2 more are in the truck bed between the rear wheel well and the box front on the driver's side. They clear the TC lower by about 2".
The hard wired inverters were from 750 watts to 2500 watts in size. The 750 to 1500 watt inverters had 3 group 31 deepcycle batteries and the 2000 and 2500 watt inverters have 7 of the same batteries in their banks. Also have 4 smaller inverters not hard wired from 300 watts to 500 watts in size. They are a wonderful source of silent 110 AC even thought we also have gas or propane fueled generators too. Generators make noise but inverters don't! They are perfect for at night TV, microwave, puter, etc or in the early morning for coffee, toast, TV, microwave, etc when no noise is wanted ever. DO NOT use an inverter for a hairdryer as it alone takes all a 2000 watt inverter can handle and will drain a battery bank real fast down to auto shutdown. As a battery's voltage drops from 12.6V the amperage draw to produce 110 AC wattage needed increases which hastens the discharge drasticly .
Example: a microwave using 1000 watts AC usually will only be running for a minute or so and the same for a toaster and most coffemakers draw 900 watts or less and run for 3-4 minutes depending on size and brand. A hair dryer however draws around 1875 watts and will be running for 5 to 10 minutes per person's use. 2 people drying their hair for 10 minutes will draw a bank of 3 group 31 deepcycle 205 minute reserve 12V batteries down to 50% as we know so well and learned NOT to do it. Wait until you can use the generator if you must use a hairdryer.
If you are hooking your inverter to the shore power AC input on your RV, you are going to be running your converter which is not needed all the time the inverter is turned on and a normal RV converter draws between 350 and 500 watts of 110 AC as it's also trying to recharge your batteries too. So you'll need a 2500 watt inverter to have even 1875 watts (15 amps) of AC usable from the RV outlets. In other words, you are wasting your battery reserve amps running the converter for nothing! To avoid this waste there's 2 ways:
1. Install a 25-30 amp relay activated by the turned on inverter to cut the AC going to your converter before the turned on inverter is plugged into the RV shorepower connection/cord.
OR
2. "I learned to do it this way". In the TT's and 5th wheels I mount the inverter in a storage area and use a remote control. $30 tops! Then ran two new 15 amp AC circuits by running two #14 household AC wire thru the basement etc of the RV and added an outlet next to the exiting RV AC outlet in the bedroom and bathroom on one 15 amp circuit in the living room and one in the kitchen on the other new 15 amp circuit. Thus, the inverter has absolutely nothing to do with the RV OEM wiring or converter and can't be shorted out or cross wired and so convenient. Merely have to move an appliance plug from the RV circuit outlet to the inverter outlet for power. How hard is that and our batteries thank us and reward us with more than double the voltage charge reserve life. The TT's and the 5th wheels have 5-7 batteries in their banks.
I did one truck camper this same way with a seperate wired circuit but found that it's just as easy to have a 6 outlet strip screwed to the wall and always plugged in to the inverter since the interior space is so much smaller. In a TC, the inverter is right on the wall under the fridge or on the side of the front step covering the fresh water tank. Simply turn on the inverter and plug into the strip and have AC anytime anywhere. Fridge auto switches over to gas as does the waterheater anyway. One battery is in the TC battery comparment and 2 more are in the truck bed between the rear wheel well and the box front on the driver's side. They clear the TC lower by about 2".
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