Residential fridge on converter

[Jack Mayer]

But nothing runs on luck this long.

Well, yeah, it does, actually.

 

You may or may not have electronics that tolerate the MSW. Some components will tolerate the funky waves forever.....some (of the same design) may fail. It is the luck of the draw.

 

I'm not saying that you have a fridge that will fail....some do run on the MSW. What I'm saying is that it is a BAD practice to design a residential refrigerator setup these days using one. Period.

 

In your case I would not modify anything - as you say, it has been running all these years so it is unlikely to fail now. But I would NEVER encourage this design in todays market.

[GlennWest]

deleted

[Chad Heiser]

Well I will just shut up. My stuff that gives no trouble is just junk according to yall.

I don't think anyone is saying your stuff is junk. The point people are trying to make is that rigs with newer electronics, including refrigerators, microwaves and others are best run on PSW inverters. Things may run fine on MSW, but they also may not so why take the chance on newer electronics.

 

Also in post 23 above, you mention you moved your refrigerator over to the inverter circuit at some point. If I remember correctly you haven't owned your Teton for that long. You say you don't understand why the factory wired it that way. Maybe it is because they also had concerns about running a refrigerator on a MSW inverter (this is assuming your residential refrigerator is still the stock unit from the factory).

[wa_desert_rat]

Every inverter is a modified square wave generator. The ones they call PSW are just much better at re-shaping the output waveform into a pure sine wave. But some of the MSW inverters had pretty decent filtering (a combination of inductors, capacitors and resistors) so that they will play well enough with others.

 

However, unless you have an oscilloscope to actually look at the waveform, you're not going to be able to tell if your MSW inverter will present sensitive devices with what they want. So you are much safer buying a Pure Sine Wave inverter.

 

Glenn really is fortunate that his MSW inverter is well designed.

 

Not all of them are... in fact not many of them are.

 

Get a PSW inverter!

 

WDR

[4x4ff]

Gosh guys,

 

I'm sorry. I didn't mean to start a fight. I just wanted to know the best way to wire in my inverter. I have to be relatively frugal at this point and pretty well already decided on a Xantrex 1000 or 1500 (I'll decide after I measure the draw on my new fridge) inverter that was a pure sine wave inverter and using a xantrex (economical) transfer relay to just run my fridge. I would love to be able to spend a couple of thousand dollars at this point but just can't right now and as long as I can get and keep this one appliance working for a period of time (and that time is ONLY going to be when I am traveling) I have reached my goal.

 

I do have to agree that it is tough to compare old electronics to new. I work for a Fire Department and on the older trucks you couldn't kill them if you tried. On the newer ones (They call in multiplexing) you get one bad battery out of six total and all sorts of weird funky stuff starts happening. I have endless stories of issues with this. What used to work just fine wont anymore.

 

Anyway......sorry for creating a mess

 

Steve

[wa_desert_rat]

 

Steve

Don't worry about it.

 

Your idea of using a single inverter to run a residential refrigerator is an idea that we have thrashed about here several times. I am in favor of it. I suspect a 600-watt PSW inverter would probably do the job, actually. And I'm not even sure you'd need a switch because, after all, your batteries are being charged by the charger which is almost certainly capable of handling the current flow needed to start your fridge up.

 

I have a switch that I can use for my planned installation (waiting until it seems like a good idea to lay on the floor for a few hours) but I wouldn't fret about just plugging the fridge into the inverter and seeing how it works first.

 

WDR

[pjstough]

So has your question been answered on how to wire the transfer switch, and the inverter?

 

Paul

[4x4ff]

So has your question been answered on how to wire the transfer switch, and the inverter?

 

Paul

Actually NO. My fridge is on a circuit with some other outlets. It would probably be easiest to just power the entire circuit with the inverter and I am ok with that. My question is.....where in this equation to I put the transfer switch?? If I put it before the circuit breaker it will probably power the entire CB box in the 5er through the main buss bar which I don't want. If I go after the breaker what do I use as a circuit breaker in the event of a short?? If that makes sence?

 

Steve

[wa_desert_rat]

You want your transfer switch to detect when AC power would be available to the fridge instead of power from the battery bank (through the inverter). To do this the most simple and effective way, would be to wire the transfer switch to the receptacle that your refrigerator would normally plug into if there were no inverter in the circuit. Then connect the inverter to the transfer switch. Then, depending upon how your transfer switch is set up, the refrigerator to the transfer switch. This is all well ahead of the circuit breaker and also will only be effective for the refrigerator and nothing else.

 

When power is on that receptable goes live, energizes the relay in the transfer switch and provides 120vac to the fridge. When power is off the relay drops and power comes from the inverter (providing, of course, you've turned it on).

 

WDR

[pjstough]

On my install, the romex to the outlets that I wanted run by the inverter was disconnected at the breaker in the main panel and pulled out of the main panel, and that romex was connected to the "load" wire coming from the auto transfer switch, the "line" wire from the auto transfer switch was connected back to the same breaker in the main panel, and the plug on the auto transfer switch was simply plugged into the inverter.

 

Depending on the location of your main panel, the auto transfer switch, and your inverter, you may have to lengthen some of the wires.

 

Paul

[4x4ff]

You want your transfer switch to detect when AC power would be available to the fridge instead of power from the battery bank (through the inverter). To do this the most simple and effective way, would be to wire the transfer switch to the receptacle that your refrigerator would normally plug into if there were no inverter in the circuit. Then connect the inverter to the transfer switch. Then, depending upon how your transfer switch is set up, the refrigerator to the transfer switch. This is all well ahead of the circuit breaker and also will only be effective for the refrigerator and nothing else.

 

When power is on that receptable goes live, energizes the relay in the transfer switch and provides 120vac to the fridge. When power is off the relay drops and power comes from the inverter (providing, of course, you've turned it on).

 

WDR

 

On my install, the romex to the outlets that I wanted run by the inverter was disconnected at the breaker in the main panel and pulled out of the main panel, and that romex was connected to the "load" wire coming from the auto transfer switch, the "line" wire from the auto transfer switch was connected back to the same breaker in the main panel, and the plug on the auto transfer switch was simply plugged into the inverter.

 

Depending on the location of your main panel, the auto transfer switch, and your inverter, you may have to lengthen some of the wires.

 

Paul

 

I am fine with doing it either way. Now I have 2 questions.

 

1) What acts as a circuit breaker when it is running off the inverter??

2) My fridge is in a slide. In order to run an additional line to the fridge for the 'Inverter power' I am going to have to run 12/3 SJOW cable instead of romex. Is that acceptable?

 

Steve

[oldjohnt]

The inverter may well have ?????? its own internal thermal overload protection which will trip out if necessary. When running on shore utility power, there should be a circuit breaker in the RV's AC distribution panel, so you should be protected either method of operation.

Where flexibility is a necessity, I would use SJ type of cord with stranded conductors as opposed to stiff Romex for sure. I might encase it in that split tube flexible conduit for added protection and where it attaches I split a short piece of 5/8 rubber heater hose and encase it all before attaching it to frame members etc.

While there are indeed certain types of electrical and electronic appliances that experience problems if using a MSW Inverter, I never hear of problems from using a PWS Inverter, therefore, unless one absolutely cant afford a PSW, I see no other engineering or logical reason to take a chance and use MSW, but to each their own and its their decision NOT ours.

.

John T