Transfer switch problem

[Weldergary]

I think I have found my problem but looking for onions. We have a 2020 Class C Coachmen MH. I recently installed a Victron inverter charger, 300
AH lithium battery and a Orion DC-DC charger. I can charge the battery from the alternator no problem.
When I plug into shore power it does it does not transfer right away. By that I mean as an example, I plugged it in at 3 PM and the next morning 7 AM it started charging. This has happen on several occasions. When I start the generator it has never transferred to charge but I have only ran the generator 15- 20 min.
I feel certain that my installation is correct. I have opened the ATS ran meter test. Suggest that it is not transferring.
I am just looking for thought or simpler experience.

Thank You

[bigchick]

i don't fully understand the problem but you suspect your transfer switch. most transfer switches will favor the generator power and connect to it if it is present, even if shore power is also present. if generator power is not present they will connect to shore power. should be easy to use a volt meter to test the generator and shore power inputs to the transfer switch and see if it is passing them to the output side. some transfer switch have a built in delay of around 2 minutes.

now your issue about not charging the batteries may be completely different. you say you are plugged into shore power but the batteries did not start charging for several hours. did you have shore power present when plugged in and the batteries were not charging, ie microwave, tv, a/c, etc. if so the transfer switch was working. the problem may be with the converter. did you take voltage measurements right at the battery terminals when you were plugged into shore power but the batteries were not charging and when they were charging?

[Archer2]

Maybe I’m having a “dumb day” but I’ve read the original post several times and I still don’t understand what is being said. The post says that they installed an Inverter/Charger and a Lithium battery AND also installed a DC to DC Charger. So I guess the idea is to have the Inverter providing 120 AC to the coach when no shore or generator is available and to have the Inverter/Charger charge the Lithium batt when external shore or generator IS connected. Then I guess when neither shore not generator is available the DC to DC chargers is supposed to charge the battery using the truck alternator?
Then he starts talking about the ATS and I get lost. The ATS is just responsible for picking either shore power or generator power and connecting one of the two to the coach 120AC circuitry (including the Inverter/Charger) but has absolutely nothing to do with the separate DC to DC Charger. I am obviously not understanding something here.

[zoso1971]

Is your MH 30 or 50 amp? If 30 amp did you take the AC from the ATS to your power distribution panel and run it to the Vic AC in instead? Then did you run new wire of same type from Vic AC out back to the power panel effectively placing the Vic inline between the ATS out and power panel in? Can we understand this much of the picture?


Before: ATS out ---> Power panel 30 amp breaker, neutral and ground busbars. Everything worked? You could power/charge from shore or gen?


After: ATS out ---> Vic AC in. (New wire) Vic AC out ---> Power panel 30 amp breaker, neutral and ground busbars. No shore or gen?

[Weldergary]

Originally Posted by zoso1971

Is your MH 30 or 50 amp? If 30 amp did you take the AC from the ATS to your power distribution panel and run it to the Vic AC in instead? Then did you run new wire of same type from Vic AC out back to the power panel effectively placing the Vic inline between the ATS out and power panel in? Can we understand this much of the picture?


Before: ATS out ---> Power panel 30 amp breaker, neutral and ground busbars. Everything worked? You could power/charge from shore or gen?


After: ATS out ---> Vic AC in. (New wire) Vic AC out ---> Power panel 30 amp breaker, neutral and ground busbars. No shore or gen?

I am sorry I am confusing the problem. Yes I have Vic AC in (new wire) and Vic AC out. When I say it is not charging the battery I should have stated it is not transferring power i.e. running the micro wave or providing power to the coach. I can plug into shore power or run the generator and I get no transfer of power.

The inverter/charger provides 120 to run (example the coffee pot, TV) and so on. The DC-DC will supply power to my inverter with the alternator thus charge my battery. I have a new ATS ordered and should install it Wed see if that fixes the problem.

[Weldergary]

Originally Posted by Archer2

Maybe I’m having a “dumb day” but I’ve read the original post several times and I still don’t understand what is being said. The post says that they installed an Inverter/Charger and a Lithium battery AND also installed a DC to DC Charger. So I guess the idea is to have the Inverter providing 120 AC to the coach when no shore or generator is available and to have the Inverter/Charger charge the Lithium batt when external shore or generator IS connected. Then I guess when neither shore not generator is available the DC to DC chargers is supposed to charge the battery using the truck alternator?
Then he starts talking about the ATS and I get lost. The ATS is just responsible for picking either shore power or generator power and connecting one of the two to the coach 120AC circuitry (including the Inverter/Charger) but has absolutely nothing to do with the separate DC to DC Charger. I am obviously not understanding something here.

Exactly, the ATS is responsible for picking up shore power or generator power and connecting one of the two to the coach. It is not. The DC- DC charger is is only for the engine alternator and it works fine. I have a new ATS ordered that i will install Wed. I was only asking if anyone else has had a simler problem. Thank You

[zoso1971]

Yes it's very much sounding like its your ATS. Let us know the outcome. We love pictures.

[Archer2]

Thanks for the further explanation. That makes complete sense now. Good luck.

[NXR]

Originally Posted by Weldergary

The DC-DC will supply power to my inverter with the alternator thus charge my battery.

That's an interesting way to accomplish charging the lithium batteries. I thought that normally the DC to DC charger takes engine alternator power and then charges the lithium batteries directly.

The DC to DC charger has two purposes. One is to provide a higher voltage than the alternator is putting out to assure the lithiums are getting fully charged.

The second one is even more important. A discharged lithium battery presents a very low electrical resistance and can act almost like a short circuit. Without an isolation mechanism it's very easy for a discharged lithium battery pack to try to pull way more current from the engine alternator than it's designed to deliver. That can and has resulted in alternator failure. So the DC to DC charger limits the current being pulled from the engine alternator to a safe value.

Ray

[bigchick]

i guess i still don't understand. i have read the posts several times and i think i see the new cabling as:

the transfer switch output goes to the ac in side of the converter / inverter. the output side of the converter / inverter goes to the power panel.

the output from the dc to dc charger goes to the 12 volt input of the inverter instead of to the battery.

maybe i really don't understand what is trying to be accomplished but this does not make any sense to me.

all ac power, either shore or generator is being routed through the converter / inverter and it's probably internal transfer switch. should the ac input to the converter / inverter be a branch circuit off the power panel with its own circuit breaker in the panel?

are both the battery terminals and the dc - dc charger outputs connected to the converter / inverter 12 volt inputs?

[Weldergary]

You are correct the DC-DC number 4 cable is run the battery. The alternator in turn charges the battery. The DC-DC charger prevents damage to the alternator. End of that system.

[Weldergary]

What as me baffled is: I was dry camping living off the 300 AH lithium battery. I have a shunt and gage to monitor the battery. After a day living off the battery it was down to about 75%. A place came open to plug into shore power so I moved 10AM 10/02/22 and plugged into shore. The transfer switch did not pick it up. No shore power to anything. Still living off the battery. At 0600 10/03/22 the battery was about 40%. At about 0700 10/03/22 the transfer kick in power to the inverter. Power to the micro wave and other. So for about 20 hours I was plugged into shore but no transfer. Then for not reason it kicked in powering up and recharging the battery. This is confusing

[Jon_C]

Maybe there was no power at the pedistal for those hours?

I had a situation at a COE campground where my power would go on and off periodically, but everyone near me was fine, it was a bad breaker feeding the pedistal.

[Weldergary]

Originally Posted by Jon_C

Maybe there was no power at the pedistal for those hours?

I had a situation at a COE campground where my power would go on and off periodically, but everyone near me was fine, it was a bad breaker feeding the pedistal.

NO power was there I checked that first. Thank You