Transfer switch installation

DougM79 · 09-06-2024, 12:10 PM

Hello!
We have no real need for the 50 amp input to our Jayco Eagle 5th wheel. As i understand, is is needed only because we have two air conditioners. (we won't use them at the same time). I will use a 30 amp pigtail to hook up shore or generator power. I will also install a 3000 W inverter for boondocking. So if i install a transfer switch, shoud i install a 50 amp switch in case we do use 50 amp? will the 50 amp switch work while hooked to 30 amp inputs?
Thank you for any insights!

NH_Bulldog · 09-06-2024, 12:27 PM

I have a couple of clarifying questions; 1) how do you intend to install the inverter, are you going to use the inverter prep loop in the forward compartment, or cobble it into the main power board? 2) what brand/model inverter are you going to use? 3) What do you intend to operate off the inverter? 4) How big is your battery bank and what type of batteries do you have?

I will have more questions, but that should get us started.

**chuckster57** · 09-06-2024, 12:30 PM

Why not install an inverter/charger with 2 AC in/out?

I just completed an installation for a customer that bought a 50A unit that has 2 bedrooms at opposite ends, 2 ACs and a residential sized 12V refer. They have no intentions of running the AC on inverter but want the ability to watch tv at both ends, on separate legs.

I also installed an Expion 360 386aH LiPo4 battery. Install was simple, no transfer switch involved.

**JRTJH** · 09-06-2024, 02:06 PM

Quote:

Originally Posted by NH_Bulldog

I have a couple of clarifying questions; 1) how do you intend to install the inverter, are you going to use the inverter prep loop in the forward compartment, or cobble it into the main power board? 2) what brand/model inverter are you going to use? 3) What do you intend to operate off the inverter? 4) How big is your battery bank and what type of batteries do you have?

I will have more questions, but that should get us started.

To continue with understanding the questions above, also where are the batteries in relation to the planned location of the inverter? Where is the power center in relation to the batteries and that planned location? The size of battery cables for a 3000 watt inverter is "very large" even for a 3 to 5 foot run. If the power center is "mid trailer" with the planned inverter location near there and the batteries are at the front of the trailer, then the size of those battery cables to power the inverter grows from "very large" to OUTRAGEOUSLY LARGE AND HEAVY"...

Plus, if the inverter loop is like Keystone's inverter loop, it's probably 12 gauge ROMEX and only supports a MAX load of 20 amps. The output from a 3KW inverter is 25 amps, which would/could overload a 12 gauge ROMEX circuit.

Stircrazy · 09-06-2024, 04:26 PM

Quote:

Originally Posted by DougM79

Hello!
We have no real need for the 50 amp input to our Jayco Eagle 5th wheel. As i understand, is is needed only because we have two air conditioners. (we won't use them at the same time). I will use a 30 amp pigtail to hook up shore or generator power. I will also install a 3000 W inverter for boondocking. So if i install a transfer switch, shoud i install a 50 amp switch in case we do use 50 amp? will the 50 amp switch work while hooked to 30 amp inputs?
Thank you for any insights!

yes install the 50 amp transfer switch. you need 50 amp for a lot more reasons than two AC's but some people will never need it, if your ac is running and you want to make coffee or use the microwave and such all at the same time 50 amp is nice.

DougM79 · 09-07-2024, 09:10 PM

Thanks for your answer! I plan on installing the inverter to the main power board. I’m deciding between the Renogy 3000 watt ( with a Minrastos switch) or a sungold 3000watt pass through. We will run a refrigerator, tv, microwave, coffee maker, toaster and rarely the airconditioner ( soft start installed). Battery bank I currently 3 sealed lead 95Ah batteries and I will add one more.

NH_Bulldog · 09-08-2024, 04:31 AM

Keep in mind that lead acid batteries can only be discharged to 50%. So even with 4 LA batteries at 95ah each, you really only have 190 usable AH. Plus at about 50lbs. each that is 200lbs. of weight. Compared to 2 LiFePO4 batteries at 100 usable AH each and you get 200ah at 50lbs. total.

In either case, you MIGHT get about 15 minutes of run time for the AC off the batteries before you have to recharge.

Okay, more questions; 1) Hopefully you have a generator? 2) What refrigerator are you going to run off the inverter? 3) where are the batteries in relation to the power center, how many feet? 4) where are you going to install the inverter in relation to the power center and batteries?

jxnbbl · 09-08-2024, 06:03 AM

Quote:

Originally Posted by DougM79

Thanks for your answer! I plan on installing the inverter to the main power board. I’m deciding between the Renogy 3000 watt ( with a Minrastos switch) or a sungold 3000watt pass through. We will run a refrigerator, tv, microwave, coffee maker, toaster and rarely the airconditioner ( soft start installed). Battery bank I currently 3 sealed lead 95Ah batteries and I will add one more.

if you go this route you should read up on the DC cable sizing as well as the AC wire gauge before you think about placement of the inverter. For a 3000W inverter you will need 4/0 cable (or equivalent) within 5-6ft of the battery bank. Then on the other side if you are feeding your power station 8-10ga wire depending on the potential amps.

**chuckster57** · 09-08-2024, 01:46 PM

I used 4/0 cable and a 400A T type fuse.

NH_Bulldog · 09-08-2024, 02:29 PM

My 2000 watt inverter uses a 250A fuse and 1/0 cables for the DC connections (I am less than 2 ft from the batteries) and 12ga Romex for the inverted outlets.

DougM79 · 09-09-2024, 04:23 PM

Well after the recommendations i am looking at the Renogy 3000W 12V Pure Sine Wave Inverter Charger. The transfer switch in internal and it is both an inverter and charger. This seems to be the most compact package. It also seems easy to install.

NH_Bulldog · 09-09-2024, 04:32 PM

Just be aware that although the Renogy has an internal transfer switch, it does not have a pass-through for the AC power. This means that unless the inverter is on, it will not transfer and will not pass through the AC power. The inverter has to be on all the time. If you read the description it refers to UPS (uninterruptible power supply). As long as you are aware of the limitations of that unit, it might be okay, but there are better options out there. This isn’t an item I would be looking for the cheapest deal on, more is better. Another consideration is that whatever does pass through the inverter, is limited by the size of the inverter. For example, a 2,000 watt inverter is limited to 25A. A 3,000 watt inverter is limited to 30A. This means that when/if you connect your 3,000 watt inverter into your main power supply, you have limited your 50A RV to no more than a 30A RV even if not using the inverter. Again, maybe that’s okay for you.

Stircrazy · 09-10-2024, 04:29 AM

Quote:

Originally Posted by DougM79

Well after the recommendations i am looking at the Renogy 3000W 12V Pure Sine Wave Inverter Charger. The transfer switch in internal and it is both an inverter and charger. This seems to be the most compact package. It also seems easy to install.

I have the 2000watt one in my truck camper, I like it so far, I primarily bought it because of the way it works with LiFePO4 batteries with the custom settings.

as mentions it is always on and if you have a 50 amp setup where you use that much power plugged in it might limit you a bit. in my 5th wheel I still have a separate inverter, charger and transfer switch so the only thing working when plugged into shore power is the charger. I would have to look at my 2000 renogy inverter converter in my camper to see if it will pass the full 30 amps or not I am not sure if it is limited or if I can get the full shore power or not, something I should check out I guess.

lcarver02 · 09-12-2024, 01:49 PM

Quote:

Originally Posted by DougM79

Hello!
We have no real need for the 50 amp input to our Jayco Eagle 5th wheel. As i understand, is is needed only because we have two air conditioners. (we won't use them at the same time). I will use a 30 amp pigtail to hook up shore or generator power. I will also install a 3000 W inverter for boondocking. So if i install a transfer switch, shoud i install a 50 amp switch in case we do use 50 amp? will the 50 amp switch work while hooked to 30 amp inputs?
Thank you for any insights!

Just keep it, use an adapter, as you will come to a 50A site and they will not let you borrow an adapter. So that is the story.

You may also like: