CavemanCharlie wrote: It's possible the problem is just that you have a cheap inverter. I do the same thing you are and have no problem with the noise you are talking about. Where did you buy the inverter? and How big is it?
It is a 300 watt unit. I dont remember where I bought it, but it has readouts on the front and I can watch the voltage in go from 13 to 10 and back.
Quote: I power my tv, dvd, laptop and charge small items with a Go Power 300w sine wave inverter.
I mounted the inverter behind the fuse-breaker panel. 12v connects to the main battery feed to the panel. 120v is wired into the entertainment area circuit with an automatic transfer switch. The wiring is very straight forward if you have done any home wiring before. The Go Power 300w has a provision for a remote power switch so with the touch of a button I have instant power.
You might be able to make the TV use less power by turning down the backlight. It worked for me. I turned it down until the fan on the inverter stopped spinning.
The whine you are hearing is because the plug that comes with the inverter is a different size (bigger) than the (smaller) RV receptacle causing poor contact on the centre pin… wiring it directly to the battery with the right size wire will help, but a low battery from furnace usage will cause it no matter how its wired…
Love my mass produced, entry level, built by Lazy American Workers, Hornet
JJBIRISH wrote: The whine you are hearing is because the plug that comes with the inverter is a different size (bigger) than the (smaller) RV receptacle causing poor contact on the centre pin… wiring it directly to the battery with the right size wire will help, but a low battery from furnace usage will cause it no matter how its wired…
I noticed that the cranking amps just isnt that high with 2 golf cart batteries. Maybe 4 would be better. I have a meter and can watch the voltage drop and drop as I turn lights on. It really drops when the slide is going out or furnace running then back up when they shut off. The Batteries last a long time but just dont put out the cranking amps from my experience. I would try measuring your amps when the furnace it running. If its in the acceptable range, I would try a different pure sine inverter like the others have stated.
Mike
2006 Ford E350 Van (standard length)
V10, 3.73, 5 Star Tuner, Hellwig Rear Sway Bar, Prodigy BC, Hensley Arrow Hitch
kinda got the same question... the owner before me had a inverter mounted in the engine compartment up under the wiper motor..not sure thats the best place for it but,,, anyways he took it out prior to selling.. so i bought one as seen below and want to run the refridge and a lcd tv while we are going down the road.. being that the alt would give me the 12v power or am i missing something ???
* This post was
edited 04/15/12 09:30am by mph_medic *
Never do anything you wouldn't want to explain to the Paramedics...
To properly install 2000w you really need to install close to the four+ house batteries with some big wire. Fridge and tv probably only need ~500 watts.
I used a Sunforce pure sine wave inverter and an Omron 4 pole relay (2 Poles Normally Open and 2 Poles Normally Closed) with a mount that allowed the relay to be screwed into a Junction Box
I put a short piece of 2x4 scrap lumber in the bottom of the junction box for spacing and to provide something to screw the relay mounts into.
The attached circuit diagram shows only one circuit energized by the relay. In my case, two relays were used to control two separate downstream circuits. One circuit feeds outlets in the back half of the trailer and the other feeds outlets in the front half of the trailer. Both of these circuits existed before I started - I simply cut the existing wires downstream of the existing circuit breakers to splice the relays into the system. With this design, one relay is needed for each circuit to be powered by the inverter. If you only want to power one downstream circuit (which might have multiple appliances on it), you only need one relay.
Two circuits within each relay are normally closed. The inverter output is attached to these. This means that no power is needed to energize the relays in order for the inverter to feed the circuits (the relay does not draw any power when running on batteries). The other two circuits are normally open. I attached the wires coming from the existing circuit breakers to these. These same wires were also attached to the energizing contacts of the relay. This means that if outside power is present, the "old" ac circuits are energized, which closes the relay and allows the current to flow just as it did before the modifications. If outside current is disconnected, then the relay de-energizes, the ac circuit opens and the inverter circuit closes. The relay design means that you can never have both inverter output and outside ac power feeding the downstream appliances at the same time (a good thing). When under outside ac power, the "old" circuit breakers protect the circuits. When under inverter power, the inverter fuses protect the circuits (this makes it important to make sure the chosen inverter has fuses or breaker protection built in). The design also prevents the inverter from back-feeding any non-desired circuits (there is no way for the inverter output to get into any circuits other than the ones it is wired up for).
All the ground (green) wires are tied together in the junction box.
* This post was
edited 04/15/12 09:15am by dforster *
dforster wrote: I am not an electrician, but this is what I did:
I used a Sunforce pure sine wave inverter and an Omron 4 pole relay (2 Poles Normally Open and 2 Poles Normally Closed) with a mount that allowed the relay to be screwed into a Junction Box
I put a short piece of 2x4 scrap lumber in the bottom of the junction box for spacing and to provide something to screw the relay mounts into.
The attached circuit diagram shows only one circuit energized by the relay. In my case, two relays were used to control two separate downstream circuits. One circuit feeds outlets in the back half of the trailer and the other feeds outlets in the front half of the trailer. Both of these circuits existed before I started - I simply cut the existing wires downstream of the existing circuit breakers to splice the relays into the system. With this design, one relay is needed for each circuit to be powered by the inverter. If you only want to power one downstream circuit (which might have multiple appliances on it), you only need one relay.
Two circuits within each relay are normally closed. The inverter output is attached to these. This means that no power is needed to energize the relays in order for the inverter to feed the circuits (the relay does not draw any power when running on batteries). The other two circuits are normally open. I attached the wires coming from the existing circuit breakers to these. These same wires were also attached to the energizing contacts of the relay. This means that if outside power is present, the "old" ac circuits are energized, which closes the relay and allows the current to flow just as it did before the modifications. If outside current is disconnected, then the relay de-energizes, the ac circuit opens and the inverter circuit closes. The relay design means that you can never have both inverter output and outside ac power feeding the downstream appliances at the same time (a good thing). When under outside ac power, the "old" circuit breakers protect the circuits. When under inverter power, the inverter fuses protect the circuits (this makes it important to make sure the chosen inverter has fuses or breaker protection built in). The design also prevents the inverter from back-feeding any non-desired circuits (there is no way for the inverter output to get into any circuits other than the ones it is wired up for).
All the ground (green) wires are tied together in the junction box.
Hi dforster,
Are the links for the inverter and relay correct? The math indicates the inverter is capable of 10 amps, but the cited relay documentation indicates the normally closed contacts of the relay are only rated for 8 amps.
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