Inverter use from battery to shore power question?

[daniel13]

I just picked up our 2020 cedar Creek 29rw and I have a question about the auto transfer from battery to shore power on the electric only refrigerator. It seems ok on the inverter battery use but doesn't switch to 110 volt unless I unplug the black plug see pic and leave the inverter on? What am I doing wrong?

[cavie]

If you unplug the fridge where is it getting power from???? Now we are both confused!!

What type of wire is feeding that outlet That is not 120 volt RX wire. At least I have never seen purple!

[CHICKDOE]

you should not have to unplug the refrigerator. there will be a small transfer (bypass) relay installed in the circuit that powers the refrigerator. this relay will switch between shore power (primary) and inverter power. depending upon the model of inverter that you have this relay may built in internally within the inverter. this will be the case if you have an inverter model that serves as both a converter and an inverter since will have a shore power lead coming into it. if it is an inverter only model the relay will be a small external device that.

since you do not have power when on shore power have you checked the shore power circuit breakers? look for on labelled refrigerator or converter and flip them fully off and then back fully on. my first guess would be that this shore power breaker that powers the refrigerator is off.

if you could post the make / model of the inverter you have that would allow us to tell whether the bypass relay is internal to it or not.

[jd4010]

With ours, when we connect to shore power the inverter light turns green and I simply push the on/off button on the inverter to turn it off. I guess I could leave the inverter on but I don't see the need to do so.

[Tall frog]

Originally Posted by daniel13

I just picked up our 2020 cedar Creek 29rw and I have a question about the auto transfer from battery to shore power on the electric only refrigerator. It seems ok on the inverter battery use but doesn't switch to 110 volt unless I unplug the black plug see pic and leave the inverter on? What am I doing wrong?

That plug is for the 110v to pass through the inverter, it should automatically change from using 12v to 110v to using the shore power. On the inverter a green light will show when you are on shore power and the inverter will show a battery condition when turned on and with no shore power. I have started turning my inverter off when an shore power but you have to remember to turn it back on when not on shore power. You should not have to pull that plug to power the frig.

[cavie]

Originally Posted by Tall frog

That plug is for the 110v to pass through the inverter, it should automatically change from using 12v to 110v to using the shore power. On the inverter a green light will show when you are on shore power and the inverter will show a battery condition when turned on and with no shore power. I have started turning my inverter off when an shore power but you have to remember to turn it back on when not on shore power. You should not have to pull that plug to power the frig.

OP said it was an Electric only fridge. No 12 volt involved.

[Tall frog]

The 12v is for the INVERTER to power the 110v frig when no shore power available

[BandJCarm]

Originally Posted by cavie

OP said it was an Electric only fridge. No 12 volt involved.

12v is involved when not connected to shore power, AND the inverter is turned ON. Batteries are being used but converted to 110 via the Inverter.


Technically, you can leave the Inverter ON nonstop, all the time. I don't, but there's no good reason to turn it off other than I just do. If inverter is on, and you're connected to shore power, it doesn't do anything. If it's on, and you're not connected to shore power, it feeds the Fridge on output and takes 12v IN from batteries (which may or may not be somewhat charging from the connection to the truck/lights wiring).

[daniel13]

The plug and inverter are in the front compartment. I believe the purple wire runs bàck to the refrigerator but have not fully traced it yet. The inverter is using the battery power and works fine on battery but when I plug into shore power the residential refrigerator goes dark unless I unplug the black plug running from the inverter. I will was wondering if anyone else has seen this before. I must be doing something wrong but have closed the unit up do to six inches of snow. I will reopen tomorrow to try and figure it out. Attached is a pic of the rear of the inverter. Thanks for helping
Dan

[MR.M]

Bad transfer switch in inverter !

[jd4010]

By the pictures it appears that your inverter is similar to mine.

The purple wire that goes into the side of the outlet is the 110v wire fed from shore power. It gets energized when you plug into shore power which then powers the receptacle. The inverter is plugged into that receptacle. You can test that by plugging a vacuum or any electric item into that outlet and if it works when on shore power but not when disconnected from shore power than that circuit is working correctly.

Your fridge is being powered by that white wire coming out of your inverter. I bet if you follow it, it "disappears" into the RV wall.

When the inverter senses no power from the receptacle (the 3 pronged plug you are disconnecting) the inverter switches to battery power converting 12v battery DC to 110v AC which powers that white wire coming from you inverter to the fridge. When the shore power energizes the black receptacle which the inverter is plugged into, the inverter does not switch to batteries to convert 12v DC to 110v AC but rather bypasses that and sends the 110v shore power current directly to the white wire and to the fridge.

I think your inverter is not switching into that bypass mode hence you have an inverter issue and a possible replacement is in your horizon.

[daniel13]

I think you are right

[cavie]

Originally Posted by BandJCarm

12v is involved when not connected to shore power, AND the inverter is turned ON. Batteries are being used but converted to 110 via the Inverter.


Technically, you can leave the Inverter ON nonstop, all the time. I don't, but there's no good reason to turn it off other than I just do. If inverter is on, and you're connected to shore power, it doesn't do anything. If it's on, and you're not connected to shore power, it feeds the Fridge on output and takes 12v IN from batteries (which may or may not be somewhat charging from the connection to the truck/lights wiring).

Very aware of how an inverter works. it came across as the 12 volts was being supplied to the fridge not the inverter.

[Rockinh]

I had a similar situation with mine. If I manually turned on the inverter, the fridge would run, but if I left it on auto, it would not. I thought it was the auto transfer switch put it turned out to be the shore power. Had a bad ground in the supply line. Powered the inverter but since it sensed shorepower, it did not transfer and the side to the fridge was on a ground fault circuit which wouldnt reset. Had to replace the shore power line, which was actually easier, or at least it would have been if I had checked it first like you should. Check the incoming first and make sure you have power and dont have a bad neutral or bad ground. Happy hunting.

[cavie]

Originally Posted by jd4010

By the pictures it appears that your inverter is similar to mine.

The purple wire that goes into the side of the outlet is the 110v wire fed from shore power. It gets energized when you plug into shore power which then powers the receptacle. The inverter is plugged into that receptacle. You can test that by plugging a vacuum or any electric item into that outlet and if it works when on shore power but not when disconnected from shore power than that circuit is working correctly.

Your fridge is being powered by that white wire coming out of your inverter. I bet if you follow it, it "disappears" into the RV wall.

When the inverter senses no power from the receptacle (the 3 pronged plug you are disconnecting) the inverter switches to battery power converting 12v battery DC to 110v AC which powers that white wire coming from you inverter to the fridge. When the shore power energizes the black receptacle which the inverter is plugged into, the inverter does not switch to batteries to convert 12v DC to 110v AC but rather bypasses that and sends the 110v shore power current directly to the white wire and to the fridge.

I think your inverter is not switching into that bypass mode hence you have an inverter issue and a possible replacement is in your horizon.

So your saying the fridge has two cords on it? You have got this 50 years master electrician confused! There should be 12 volt TO the inverter from the battery and 120 volts TO the inverter from shore power and 120 volts out of the inverter. The black rubber cord on the inverter is the supply cord from shore power. This is the first I have seen Purple Romex. Somebody please tell me where the purple wire comes from. Common sence wold be that it is the inverted power from the inverter. The inverter has a built in transfer switch that changes from shore power to 12 volt inverted power to the same outlet the fridge is plugged into. I don't understand how unplugging that cord makes the fridge work. Somebody with experience please explane this. I guess i am just getting old. I do know that the white Romex at the transfer switch has some nasty twists in it at the Rx connector and a very good place for a short.

If the purple wire is shore power and the plug shown is the inverter power cord then I understand the the white romex is going to the fridge meaning the transfer switch is bad and removing the shore power cord forces it to work off the battery YES?

[5picker]

Originally Posted by cavie

So your saying the fridge has two cords on it? You have got this 50 years master electrician confused! There should be 12 volt TO the inverter from the battery and 120 volts TO the inverter from shore power and 120 volts out of the inverter which should be the purple wire. This is the first I have seen Purple Romex. The inverter has a built in transfer switch that changes from shore power to 12 volt inverted power to the same outlet the fridge is plupgged into. I don't understand how unplugging that cord makes the fridge work.

cavie, reread the post you quoted. (post #11]

He's NOT saying there are two supply feeds to the refrigerator.

The black receptacle with the purple romex is where the inverter is plugged into and gets its 120v feed.

The refrigerator gets its feed from the white romex wire out of the back of the inverter.

By pulling the plug at the black receptacle with the purple wire, they are essentially disconnecting the inverter's 120v sensing feed and the refrigerator is running off of 12v to 120v inverted power.

There is something wrong with the inverter's switching circuit. Whether that switching circuit is internal to the inverter or separate remains to be seen as we don't know the make/model of the inverter.

[cavie]

Originally Posted by 5picker

cavie, reread the post you quoted. (post #11]

He's NOT saying there are two supply feeds to the refrigerator.

The black receptacle with the purple romex is where the inverter is plugged into and gets its 120v feed.

The refrigerator gets its feed from the white romex wire out of the back of the inverter.

By pulling the plug at the black receptacle with the purple wire, they are essentially disconnecting the inverter's 120v sensing feed and the refrigerator is running off of 12v to 120v inverted power.

There is something wrong with the inverter's switching circuit. Whether that switching circuit is internal to the inverter or separate remains to be seen as we don't know the make/model of the inverter.

Yep, your explanation above is exactly what I stated in my last paragraph. I know he did not say there where two cords but his explanation was not clear to me. I was making the assumption the the plug was the fridge plug. Have you ever seen purple Romex?? I am retired 4 years now and try to stay out of the supply houses. Spent enough time in them in 50 years.

[5picker]

Originally Posted by cavie

Yep, your explanation above is exactly what I stated in my last paragraph. I know he did not say there where two cords but his explanation was not clear to me. And it was never stated what the plug actually went to. Have you ever seen purple Romex?? I am retired 4 years now and try to stay out of the supply houses. Spent enough time in them in 50 years.

Yes I have seen purple romex in the RV industry, along with lime green, orange, yellow, red, white and even black!... all the same gauge!

The R/V industry has the stuff made so the factory workers can more easily identify circuitry.

They do the same with coax cable but even then it often gets connected incorrectly.

I know you know this but... not everything you come to know in your 50 year sticks and bricks career can be applied when it comes to R/Vs.

Oh... and you added your last paragraph in post # 15 in an edit AFTER I posted my reply to you. [emoji6]

[daniel13]

Thanks for your input. The purple cable is supply Power 110 volt and that is working as I plugged a vacuum cleaner in it and it ran. If I leave the black cable plugged in to the inverter it shows that it sees the 110 but will not switch over to the 110 when unplugged it sees the batteries and runs off them perfectly fine. The batteries are charged by the converter and solar so are able to keep the fridge running

[cavie]

Originally Posted by 5picker

Yes I have seen purple romex in the RV industry, along with lime green, orange, yellow, red, white and even black!... all the same gauge!

The R/V industry has the stuff made so the factory workers can more easily identify circuitry.

They do the same with coax cable but even then it often gets connected incorrectly.

I know you know this but... not everything you come to know in your 50 year sticks and bricks career can be applied when it comes to R/Vs.

Oh... and you added your last paragraph in post # 15 in an edit AFTER I posted my reply to you. [emoji6]

This is the first time in my 4 years of being on RV forums that I have heard or seen of Colored RX other than the standard white, yellow and orange. We all learn something every day. Didn't know there is special wire made just for dumb assembley workers.

Common sense would have put the purple wire from the inverter to the fridge identifying it as the inverted circuit. It would have purpose. But that's just me.