Generator will not charge house batteries

[gmc]

Originally Posted by Machinetools1

GMC. We are home from our trip and had a fantastic time. Now I need to find the problem of not charging the batteries when the generator is running. I did not check the voltage coming out of the converter but I am confused. A converter converts AC to DC and an inverter converts DC to AC. when you turn the inverter on to watch tv it powers all of your 120 componates so you can watch t.v. would that not 've the job of the converter and not the inverter.

With the generator on I should be getting 13 volts out of the converter and the batteries. How many volts should be coming out of the inverter.

Glad you had a great time!

The converter as you said converts 110v AC to 12v DC... It is used to provide 12v to the coach when shore power/generator power is present - and of course also charges the coach batteries (and chassis on most class A's)
The inverter converts 12v DC to 110v AC - Typically the inverter powers only a few items in most RVs - residential fridge if present, TVs are another common one... (Large diesel pushers power virtually everything...)
The inverter typically has an internal transfer switch - so if 110v power is available from either generator or shore power - it just passes it through... It only 'inverts' 12v to 110 when no 110 source is present.

So with generator on - the output of the inverter should be the 110v from the generator.

With the generator off/shore power disconnected, the output should still be 110v, but would be the result of inverting the 12v input.

[Machinetools1]

Originally Posted by gmc

Glad you had a great time!

The converter as you said converts 110v AC to 12v DC... It is used to provide 12v to the coach when shore power/generator power is present - and of course also charges the coach batteries (and chassis on most class A's)
The inverter converts 12v DC to 110v AC - Typically the inverter powers only a few items in most RVs - residential fridge if present, TVs are another common one... (Large diesel pushers power virtually everything...)
The inverter typically has an internal transfer switch - so if 110v power is available from either generator or shore power - it just passes it through... It only 'inverts' 12v to 110 when no 110 source is present.

So with generator on - the output of the inverter should be the 110v from the generator.

With the generator off/shore power disconnected, the output should still be 110v, but would be the result of inverting the 12v input.

I have an appointment with the RV dealership but it is 2 months out. I can fix this myself I just need to understand the concept. What is the best way to test the converter and the inverter with a volt meter. I believe the converter is the issue and not the inverter. As it he inverter does not charge the battery but the converter does with the generator on. Also with the inverter on everything works. What is the best way to test the converter. As stated earlier I can fix this myself I just. Need to know how.

[16ACE27]

Originally Posted by Machinetools1

I have an appointment with the RV dealership but it is 2 months out. I can fix this myself I just need to understand the concept. What is the best way to test the converter and the inverter with a volt meter. I believe the converter is the issue and not the inverter. As it he inverter does not charge the battery but the converter does with the generator on. Also with the inverter on everything works. What is the best way to test the converter. As stated earlier I can fix this myself I just. Need to know how.

If you don't have a hand held voltmeter:

Start the generator
turn on interior lights and Air Conditioner (if you want)
Place the USE/STORE switch in STORE
If the converter is working the lights and Air Conditioner will stay on.
If the converter is not working, both will go off: The lights due to loss of 12 VDC, the Air conditioner due to loss of 12 VDC control power to the thermostat.

[Machinetools1]

Originally Posted by 16ACE27

If you don't have a hand held voltmeter:

Start the generator
turn on interior lights and Air Conditioner (if you want)
Place the USE/STORE switch in STORE
If the converter is working the lights and Air Conditioner will stay on.
If the converter is not working, both will go off: The lights due to loss of 12 VDC, the Air conditioner due to loss of 12 VDC control power to the thermostat.

Well, we got home and I followed your sequence. I could not believe it, I turned off the Use/ Store switch and the air and all the lights stayed on....and for the first time it was charging in the green over 14 volts. I turned the Use/ Store off and on again and it was still charging in the green. I let the generator charge the batteries for about an hour. I then turned on all the lights and tv's and let the batteries drain to 11.5 volts. repeated the process and when I turned the Use/Store switch off everything went dead. I repeated the process again with the same results....dead. So I turned all the power off and took a look at the inverters connections. the positive and negative connections were super loose but I think the problem was the 110 cord that plugged into the 110 receptacle. it was hanging out of the receptacle and was not getting a good connection. The wiring is not very neat under the bed and this was the first time I completely shut all the power off and got my hands deep into the wiring. I tried the same procedure 5 more times with positive results. when you have a better understanding of what you are doing it makes things much easier. I want to thank everyone for walking me through this little situation I had. I am very grateful to have a forum where people can help each other with their problems and issues. All of our ultimate goals are to enjoy something we all love to do and that is enjoying our rv's. Again thank you.

[Sandyfou]

I don’t know if you have this on yours but our generator has an on/off switch just like a light switch on the generator it can get tripped if it’s off of course it won’t charge the batteries. It will run but not charge

[16ACE27]

Originally Posted by Sandyfou

I don’t know if you have this on yours but our generator has an on/off switch just like a light switch on the generator it can get tripped if it’s off of course it won’t charge the batteries. It will run but not charge

That's not an on/off switch: that is the output breaker for the generator. When tripped or OFF the generator will not supply any 120 VAC power to the coach, so nothing operates except battery powered appliances, AND the converter will not charge the batteries.

[BASSMAN]

I know there are many variations of inverters out there but in my case my converter ( I like to call it the on board battery charger ) is built in the Inverter, to check my 12 volt side of my inverter to verify if the converter is charging I remove the positive and negative battery cables from the inverter and either plug in the shore power or fire up the generator and put a multi meter on the positive and negative post of the Inverter, if you have no reading then the converter part of the inverter is not working, the inverter must be on to check this and make sure you wrap the positive battery cable end with lots of tape as soon as you remove it from the inverter and keep it protected, this is a simple test and can eliminate a lot of searching for something else that might not be a issue.

[Machinetools1]

Well, thought I had it fixed. I turned on the USE/STORE rocker switch, both air conditioners and all the lights. I waited to hear the click under the bed and see the clock come on in the microwave. I turned of the USE/STORE rocker switch off and everything went dead. I tried this same procedure one more time with the same results. I turned the USE/STORE switch and the generator back on and checked the power coming into the converter and I am getting 110 volts coming into the converter. I checked the voltage with the batteries hooked up to the Converter and had 11.6 volts, that is what the batteries were charged at. I then carefully unhooked the positive and negative from the batteries that went to the converter. The voltage was 0 volts. I thought I found the problem. I took the converter out and bench tested the converter by plugging the converter into 110 volts of shore power and checking the positive and negative posts with my volt meter. I got 13.6 volts. This is what the manual states it should be. I let it run on shore power for an hour and got the same results at 13.6 volts from the battery lugs with my volt meter. What else in the wiring system would cause all the power to go out when you turned off the USE/STORE rocker switch?

On shore power everything works well, and the batteries get charged. With the generator on everything works but the batteries do not get charged. I am thinking it has do with the wiring to the batteries or there is a hidden fuse somewhere that is not visible?

Is the latching relay the same as the bypass relay, transfer switch, and the auto transfer switch? I have read these different terms and just want to make sure we are all talking about the same thing. I also read the latching relay is the same as the USE/STORE switch are the same. I believe my latching relay switch is under my bed. It has 2 fuses a small relay box and a small circuit board on the big relay. Can someone explain exactly what this thing does.
I went back to work and have not got a chance to get back to my issue. When I get back at it I will post some pictures and do more voltage tests.

[BASSMAN]

what is the brand an model of your inverter, is the converter part of the inverter or is it separate, my converter is in the bottom of the breaker box, after I bought my inverter/converter combo I disconnected the original converter, I had installed gel cel batteries and they do not charge the same as lead acid batteries and my inverter/converter has a selector switch to set to the type of battery being used, as I read your post your issue is the batteries do not charge wile using the generator but you have AC power for the microwave and air conditioners? the transfer switch is used to isolate the output of the generator from the output of the shore power, with the generator off and shore power plugged in the power goes from shore power to the transfer switch and out of the transfer switch and into your breaker panel to your main breaker, the connection between the shore power and the breaker is in the normally closed position and you are running on shore power, when you start your generator the transfer switch will open the connection from shore power to your breaker box and close the connection between the generator and the breaker box, this keeps shore power isolated from the generator, there is also a delay so the generator has a chance to get up to speed before it takes over, did your inverter come new with the coach and has any electrical work been done just before this problem started?

[BASSMAN]

What part of California do you live in?

[Machinetools1]

The inverter brand is WFCO model WF-5110R true sine wave inverter and the Converter is WFCO Ultra III Deck mount Converter WF-9800 Series, both are separate units. The converter is mounted just above the breaker box. After I get home from work tomorrow, I will get some pictures posted of what I have.
With the generator running and my USE/STORE switch turned on. I turn on the air conditioning and all lights will work until I turn the USE/STORE rocker switch off and everything goes out.

When I am on shore power and the air conditioning and all lights on everything works with the USE/STORE switch in the USE position. I have not tried turning off the USE/STORE switch to STORE position yet, I did not think about it.

I have a rebuilt Xantrex Freedom 458 I was thinking about putting in but I do not think this is a converter, only an inverter and charger.

Wanted to try and figure out the problem with the system I have before I change out anything. Everything came with the RV new and its all factory.

I live about 50 miles South West of Fresno in Coalinga CA.

[javelin]

Originally Posted by Machinetools1

Well, thought I had it fixed. I turned on the USE/STORE rocker switch, both air conditioners and all the lights. I waited to hear the click under the bed and see the clock come on in the microwave.

Did you hear the click? That is the transfer switch moving from shore power feed to the gen power feed. It usually takes 30 seconds after the gen starts for the transfer switch to cut over to the gen feed.



I turned of the USE/STORE rocker switch off and everything went dead. So it sounds like the transfer switch did not operate because if it had you should have had the coach 120vac circuits working A/C etc



I tried this same procedure one more time with the same results. I turned the USE/STORE switch and the generator back on and checked the power coming into the converter and I am getting 110 volts coming into the converter. What converter output voltage do you read with use/store turned off? If you turn off gen and connect shore power (transfer switch returns to shore power feed) do you still get 120vac on the input of the converter? If yes what do you measure now on the output of the converter with use/store off? With use/store on?



I checked the voltage with the batteries hooked up to the Converter and had 11.6 volts, that is what the batteries were charged at.
Your coach batteries are fully discharged at anything below 11.9vdc; full charge is 12.6vdc for wet cell types (AGM will be different); but if you measured coach battery terminal voltage at the DC output of the converter then it sounds like the converter is not working with gen as source (from your descriptions).



I then carefully unhooked the positive and negative from the batteries that went to the converter. The voltage was 0 volts. So are you disconnecting cables at the coach batteries; then testing voltage on the wire coming from the converter to chassis ground? Zero VDC would indicate output of converter is dead because previously when the cables were hooked to coach batteries you measured battery terminal voltage at the converter output (so all breakers and use/store latch relay should be good between batteries and converter).



I thought I found the problem. I took the converter out and bench tested the converter by plugging the converter into 110 volts of shore power and checking the positive and negative posts with my volt meter. I got 13.6 volts. This is what the manual states it should be. I let it run on shore power for an hour and got the same results at 13.6 volts from the battery lugs with my volt meter. What else in the wiring system would cause all the power to go out when you turned off the USE/STORE rocker switch?

On shore power everything works well, and the batteries get charged. With the generator on everything works but the batteries do not get charged. I am thinking it has do with the wiring to the batteries or there is a hidden fuse somewhere that is not visible?

Is the latching relay the same as the bypass relay, transfer switch, and the auto transfer switch? Use/Store Switch operates or releases latching relay (look at post #13 right side of schematic); never heard of bypass relay; transfer switch and auto transfer switch are the same thing.



I have read these different terms and just want to make sure we are all talking about the same thing. I also read the latching relay is the same as the USE/STORE switch are the same. Use/store switch typically operates or releases the latching relay.


I believe my latching relay switch is under my bed. It has 2 fuses a small relay box and a small circuit board on the big relay. Can someone explain exactly what this thing does. I think you might be describing the transfer switch.....which has a small circuit board inside that is the timer circuit that determines the time from when the gen starts to when the transfer relay switches to the gen 120vac input feed.


I went back to work and have not got a chance to get back to my issue. When I get back at it I will post some pictures and do more voltage tests.

My comments and questions are in blue. Part of the problem is sometimes descriptions of where voltage tests are actually being done can be confusing.

[10scDust]

Originally Posted by Machinetools1

GMC. We are home from our trip and had a fantastic time. Now I need to find the problem of not charging the batteries when the generator is running. I did not check the voltage coming out of the converter but I am confused. A converter converts AC to DC and an inverter converts DC to AC. when you turn the inverter on to watch tv it powers all of your 120 componates so you can watch t.v. would that not 've the job of the converter and not the inverter.

With the generator on I should be getting 13 volts out of the converter and the batteries. How many volts should be coming out of the inverter.

Not an expert on your generator battery charging problems, but I want to say from my experience (not same problem though), is that the converter takes 110 vac and converts it to 12 vdc.
You can hear the cooling fan running when it is operating.
Our converter is located behind the 12 vdc fuse panel & 110 vac breaker panel.

I had to replace ours, and when the converter is running, it is putting a charge to the 12vdc house batteries.
I would say, with your generator running (allowing sufficient time for its power output to engage), you should hear the converter's fan running, and it putting out 12 vdc to your batteries.
If not, start investigating between there.

The inverter takes 12 vdc and inverts it to 110 vac.
The panel that turns on the inverter can be prompted to tell you dc voltage from source inverter is using.
When this panel is on, it is drawing from the coach batteries, to invert dc power to ac power, to power the entertainment system outlets (ours are conveniently hidden so not to be used for other plug in appliances, e.g. a shop vac).

I believe the "Use" switch needs to be on during all of this, but not sure.

I also believe the BIM senses low charge needed of both the coach, & house batteries, and if enough of a differential between them, will allow cross feed to help charge the other, in either direction.
House to coach, or coach to house.

Hoping this does not confuse anyone.

GMC & Javelin have a logical test plan.

[Machinetools1]

Hello Javelin, I hope your day is going well. First offthank you for helping me get a better understanding of the electrical system inmy motorhome.
First off, with the USE/STORE rocker button on and when Iturned on the generator it was about 20-30 seconds before I heard the snap of somethingengaging under the bed and I saw the clock on the microwave turn on ( I had themattress off the bed and the plywood panel off and was looking at the wiring, justnot sure where the sound came from. I believe it came from the transfer switch,I will pay more attention next time). Allthe lights and both air conditioners were on and under generator power andbefore I turned the USE/STORE switch off everything was working but thegenerator was not charging the batteries. I turned off the USE/SHORE rocker button of and everything died. At thistime when I was under generator power, I did not have the 50-amp shore powerconnected to the motorhome and it was not getting 50-amps from my house. It wasunplugged. I did not think I wanted the50-amp shore power plugged in and getting power from the house at the same timeI was running the generator for power. I thought if I was running the generatorand I turned the USE/SHORE rocker switch to SHORE (disconnecting) it wouldresort back to using the power from the 50-amp shore power and I would not seeif the converter was charging the batteries as the shore power would becharging the batteries. I think I amwrong on this thinking. Should I have the 50-amp shore power connected when Ihave the generator on when I do this test?


What converter output voltage doyou read with use/store turned off?If you turn off gen and connect shore power (transfer switchreturns to shore power feed) do you still get 120vac on the input of theconverter? If yes what do you measure now on the output of the converter withuse/store off? With use/store on?




I did not check the output voltage with the USE/STORE turnedoff. I did not check the input power for the converter when I was connected toshore power. I will check today after I get off work. When I check do I keep the (Red) positive and(White) neutral connected to the output of the converter or do I unhook themand just check the output lugs?


Your coach batteries are fullydischarged at anything below 11.9vdc; full charge is 12.6vdc for wet cell types(AGM will be different); but if you measured coach battery terminal voltage atthe DC output of the converter then it sounds like the converter is not workingwith gen as source (from your descriptions).


I discharged the batteries on purpose so Ican see if the converter was going to charge the batteries with the generatorrunning. I checked the voltage of the converter at the output side but the (Red)positiveand the (White) neutral were still hooked up to the output of the dc side ofthe converter. This is when I read the11.9 volts telling me the generator was not charging the house batteries.

So are you disconnecting cables atthe coach batteries; then testing voltage on the wire coming from the converterto chassis ground? Zero VDC would indicate output of converter is dead becausepreviously when the cables were hooked to coach batteries you measured batteryterminal voltage at the converter output (so all breakers and use/store latchrelay should be good between batteries and converter).


I did not disconnect the wires on the batteryterminals but the (Red) positive and the (White) neutral coming out of the dcside of the converter. I left the ground wire still connected to the converterwhen I tested the dc output of the converter.

Use/Store Switch operates orreleases latching relay (look at post #13 right side of schematic); never heardof bypass relay; transfer switch and auto transfer switch are the same thing.

I thank you for that diagram and it helps me alot. I thought the latching relay was my transfer switch. I see where my transfer switch is as it isunder my bed. I am just not sure wheremy latching relay is. When I get home, Iwill take pictures and you can explain to me where it is.

I understand where the USE/STORE switch is and itturns all the power off of the motorhome if you are running on the converter and not on shore power or generator power.
I understand the transfer switch has about a 30 second timer that transfers from generator to 120 vac. Does the transfer switch go both ways... from generator to 120 vac and from 120 vac to generator or does it go just one way.
What does the latching relay do again?

[BASSMAN]

Machinetools1, I looked up your Inverter and Converter on WFCOs web site, I did not see anything out of the ordinary, my son is an electrician and was working for Solar City before Tesla bought them out, now my son is on his own with a mobile business doing residential and RV solar packages and service, he works the Southern California area and has his hands full right now due to all the Power Cut offs by PG&E, if he was in your area I would have him swing by and take a look, One thing I notice in your post is you list at one time a USE/STORE SWITCH and a USE/SHORE SWICH, the USE/STORE SWITCH should be on at all time, only time you switch to STORE is when you STORE your coach for the season, there is a solenoid under the bed and its controlled by the USE/STORE SWITCH, this will disconnect all your 12 volt DC power to the coach, the click you hear when you start your generator is the transfer switch, there is a spring in the switch that holds the contacts in the NORMALLY CLOSED POSITION, in this position the shore power goes from the transfer switch to the breaker panel, the contacts inside the transfer switch for the generator are in the NORMALLY OPEN POSITION, once the generator is started the solenoid in the transfer switch will move the contacts from the shore power contacts to the generator contacts, this is the click you hear, the shore power connection in the transfer switch is now in an open position, the output wires from the transfer switch go directly to the breaker panel, shore power or from the generator its the same wires, I would check your 110 AC voltage going into the converter when the generator is running, if you are not getting a full 110/120 AC volts you might have a problem with the generator output, low voltage can cause lots of problems and low voltage is usually a bad connection, some inverters have the output from the transfer switch go directly to the inverter and then to the breaker panel, and then some have only a few 110 volt circuits going from the breaker panel into the inverter, I have seen many different ways of wiring in the inverter, do you have a USE/SHORE SWITCH or is this just a typo?

[Beau388]

Let me see if I can help. The Use/Store switch controls the latching relay which is located in the left front corner of the under-bed electrical compartment. It is beside the Rapid Camp circuit board. There is in an 8 gauge cable that runs from the battery compartment (through the 50 amp circuit breaker) to the relay. The relay is also wired to the 12 volts section of the power center under the bed. The purpose of the latching relay is to remove the connection of the house batteries from the power center and the power center's 12 volt converter. This is a 12 volt direct current circuit.



The automatic transfer switch (ATS) is located under the bed. It is the 120 volt device between the shore line inlet and the power center Its normal mode is to supply 120 volt power to the power center. Its primary purpose is to prevent (isolate) the shore lower cable from becoming live when the generator is supplying 120 volt power to the power center.


The inverter bypass relay's (integral to most RV inverters) purpose is to supply 120 volt power from the power center to selected RV 120 volt circuits bypassing all functions of the inverter. When no 120 volt power is available from the power center, the bypass relay will open and allow the inverter to invert 12 volt DC power into 120 volt AC power and supply power to the selected circuits (assuming the inverter is on). The inverter is also located under the bed and is the largest electrical object under the bed.


Latching relay if upper right. Below is the ATS. Silver box to the right is converter and power center. Foreground, center is EMS. Far left in the inverter. Yes, my wiring is messy - a project of the winter

[Machinetools1]

Bassman, sorry about that it was a typo. I have a USE/Store rocker switch and not a USE/SHORE rocker switch my bad. I thought if you leave the USE/STORE switch on it would eventually run your batteries down if you were not using your motorhome for a couple of weeks.

We had a 40-foot Weekend Warrior toy hauler for 12 years before we purchased this motorhome. Everything in this motorhome fits like sardines in a small can. The wiring and electrical items were spread out a lot more in the toy hauler. I guess we had the same components in the toy hauler but never experience this type of joy. Life is a learning experience and I am up for the challenge for sure.
I was a machinist for almost 25 years before I went on to this job I have now. Mechanically I can make anything but never really understood the electrical aspect. Its kind of funny as I was never good at math and that is something needed in machining. You learn basic formulas and angles you use the most and you work around your short comings to be better.

With the generator running I was getting 120 volts ac from the ac plug in where the ac converter was plugged into. I was getting the same with the generator off and shore power reconnected.

[16ACE27]

Charging the batteries is no different whether you are using the Shore Power supplied 120 VAC or the Generator supplied 120 VAC: They both supply the converter with 120 VAC which the converter uses to make 12 VDC to supply the 12 VDC loads AND charge the battery if the USE/STORE switch is in USE AND the supply breaker near the battery is no tripped open.

You can run the Generator when Shore Power is connected, but once the Generator delay connects its 120 VAC to the Breaker panel through the Automatic Transfer Switch (ATS) the Shore Power will not be supplying any loads.

[Machinetools1]

Beau388, Thanks for the clarification. So the latching relay and the Automatic Transfer Switch (ATS) are both under the bed. I need to watch, feel, and hear what switch sounds when I click on the USE/STORE rocker switch and when the generator clicks over via the (ATS). I enhanced your photo and I understand the picture of where your items are under the bed. Is your USE/STORE switch by the door when you come in or is it by the latching relay on the outside of the bed frame? My wiring is just as bad but I do not have the skills to clean it up as of yet.

[javelin]

Originally Posted by Machinetools1

Hello Javelin, I hope your day is going well. First offthank you for helping me get a better understanding of the electrical system inmy motorhome.

Glad to try to help you, as are many other contributors. I am probably confusing things more with long winded comments than helping (hope you are not color blind). Sometimes just understanding what and how tests were made can create lots of confusion. When we have problems with our coaches it is an opportunity for you (and others on the Forum) to learn more about your coach (and maybe through having similar systems, their own coach as well). The caveat to this is if you are not electrically competent then it is better to take your coach to a Dealer or have a trained mobile RV tech solve the problem.



First off, with the USE/STORE rocker button on and when Iturned on the generator it was about 20-30 seconds before I heard the snap of somethingengaging under the bed and I saw the clock on the microwave turn on ( I had themattress off the bed and the plywood panel off and was looking at the wiring, justnot sure where the sound came from. I believe it came from the transfer switch,I will pay more attention next time). Allthe lights and both air conditioners were on and under generator power andbefore I turned the USE/STORE switch off everything was working but thegenerator was not charging the batteries. I turned off the USE/SHORE rocker button of and everything died. At thistime when I was under generator power, I did not have the 50-amp shore powerconnected to the motorhome and it was not getting 50-amps from my house. It wasunplugged. I did not think I wanted the50-amp shore power plugged in and getting power from the house at the same timeI was running the generator for power. I thought if I was running the generatorand I turned the USE/SHORE rocker switch to SHORE (disconnecting) it wouldresort back to using the power from the 50-amp shore power and I would not seeif the converter was charging the batteries as the shore power would becharging the batteries. I think I amwrong on this thinking. Should I have the 50-amp shore power connected when Ihave the generator on when I do this test?


So this operation description of the transfer switch sounds normal. What I would suggest as a start though, is to actually minimize your coach 120VAC loads as much as possible before operating the transfer switch (by starting the gen) and before returning to shore power ( by stopping the gen). The reason is when major loads are on during transfer operation the electrical contacts in the transfer switch can take a beating plus the generator gets hit with major loading (when going to gen feed). Not that it can’t handle it, but de-loading prior to using the transfer switch can extend the contact life of the transfer switch. Also the auto-transfer switch (as opposed to a manually controlled one) is designed to trigger its timer when it senses 120vac voltage coming from the generator output. The transfer switch is housed in a metal electrical box together with a circuit board which typically delays the transfer to gen feed by 30 seconds. This gives the gen time to get up to speed and warm up slightly before being loaded up. It is actually good practise to de-load the gen for a few minutes (turn off A/C’s for example) before shutting off the gen, to allow a cool off period. When the gen 120vac output voltage drops the auto transfer switch will automatically switch back to shore power. Normally the transfer switch will only allow either gen or shore power through to the coach power distribution panel; never both at the same time unless something is seriously broken.



The only reason I was asking if you had done measurements on the 120vac input to the converter from both shore and gen power sources, is to determine if the transfer switch is working (this also assumes the AC breakers in the input to the electrical panel are not tripped open). If you see the 120vac when shore is coming through the transfer switch but not when gen power is coming through the transfer switch, then the transfer switch relay or its connections are suspect on the gen side. Sometimes breakers trip open but still loo like they are on, so it might be worth turning the AC main breakers in your electrical panel off and then on again.



What converter output voltage doyou read with use/store turned off?If you turn off gen and connect shore power (transfer switchreturns to shore power feed) do you still get 120vac on the input of theconverter? If yes what do you measure now on the output of the converter withuse/store off? With use/store on?




I did not check the output voltage with the USE/STORE turnedoff. I did not check the input power for the converter when I was connected toshore power. I will check today after I get off work. When I check do I keep the (Red) positive and(White) neutral connected to the output of the converter or do I unhook themand just check the output lugs?

When measuring DC voltage at the output of the converter (main DC output terminals should be close to where the small fuses are plugged in) the red cable is usually + and the white cable is usually – or chassis/battery ground. Don’t confuse the 120vac side cabling of the converter (one of the two 120vac feeds from the 50 amp transfer switch will feed the converter and other loads too) hot and neutral wires with the red and white wires on the DC output side of the converter. Also make sure your meter is configured to read AC or DC voltages when appropriate. It is safest to leave the converter output cables attached especially if they are still hooked up to the coach batteries at the other end. Do you hear your coach latching relay operating and releasing (a clunk) when you turn the use/store switch on and off? Yes is good (we will assume its relay main contacts are also good but they may not be). Start by turning the use/store “off”. When on either gen or shore power you should be able to turn on DC lights and fans in the coach......do they work? If not, measure DC volts on red and white terminals near the small fuses in the converter. Probably should see about 13+VDC. If not do you see 13+VDC when either gen or shore power is on?





Your coach batteries are fullydischarged at anything below 11.9vdc; full charge is 12.6vdc for wet cell types(AGM will be different); but if you measured coach battery terminal voltage atthe DC output of the converter then it sounds like the converter is not workingwith gen as source (from your descriptions).


I discharged the batteries on purpose so Ican see if the converter was going to charge the batteries with the generatorrunning. I checked the voltage of the converter at the output side but the (Red)positiveand the (White) neutral were still hooked up to the output of the dc side ofthe converter. This is when I read the11.9 volts telling me the generator was not charging the house batteries.

So are you disconnecting cables atthe coach batteries; then testing voltage on the wire coming from the converterto chassis ground? Zero VDC would indicate output of converter is dead becausepreviously when the cables were hooked to coach batteries you measured batteryterminal voltage at the converter output (so all breakers and use/store latchrelay should be good between batteries and converter).


I did not disconnect the wires on the batteryterminals but the (Red) positive and the (White) neutral coming out of the dcside of the converter. I left the ground wire still connected to the converterwhen I tested the dc output of the converter.

Use/Store Switch operates orreleases latching relay (look at post #13 right side of schematic); never heardof bypass relay; transfer switch and auto transfer switch are the same thing.

I thank you for that diagram and it helps me alot. I thought the latching relay was my transfer switch. I see where my transfer switch is as it isunder my bed. I am just not sure wheremy latching relay is. When I get home, Iwill take pictures and you can explain to me where it is.

I understand where the USE/STORE switch is and itturns all the power off of the motorhome if you are running on the converter and not on shore power or generator power.
I understand the transfer switch has about a 30 second timer that transfers from generator to 120 vac. Does the transfer switch go both ways... from generator to 120 vac and from 120 vac to generator or does it go just one way.
What does the latching relay do again?

The coach latching relay connects the converter DC output to the coach batteries through a typical 50 amp mini re-settable cct breaker. Find the latching relay on my generic diagram. You will see it connects converter to the batteries through a 50 amp breaker. Note the draing is only the DC connections and it is generic.....meaning it is a representation and is not a schematic that exactly matches your coach. The latching relay can be anywhere in the coach but I would bet money that it and the 50 amp mini breaker are under your bed somewhere. Follow the red wire that is the DC output from your converter and see what it connects to under the bed as a start.