Need input on Transfer Switch Manual Options

[FloHauler]

So I’m sitting here minding my own business in almost 100° degree heat plugged into shore power with the AC and some other 120 V loads running. I hear a click, and all the 120 V dies. I did a couple quick checks with my voltmeter and there is no 120 V power anywhere. Long story short, the prior owner routed the 120 V feed to the house panel through the 3000 W AIMS Power inverter charger. For whatever reason, the main push button disconnect on the inverter charger tripped. Pressed it back in, and I am back in business. That is the condensed version, leaving out swearing and other troubleshooting steps that I took.

There is a pro/con to routing power this way. A pro is if the incoming shore power is not clean, the inverter charger deals with the voltage differences and frequency differences within reason. A con is what I just experienced. The LED display for the inverter charger had no error codes, yet it dumped power at its main breaker. No house breaker tripped. Aside from doing some quick wiring surgery, if the inverter charger fails, there is no way to use the 120 V circuits.

So, I’m sitting here thinking about a manual transfer switch to be able to directly feed the 120 V house circuits from shore power, or from the inverter charger.

The inverter charger is supposed to be able to input the shore power feed, provide 120 V to the RV, and recharge the batteries as needed. That is a pro. The con is that the prior owner introduced some wire that runs inside the inverter charger that is doing what, I don’t know. The only way to figure that out is to remove the inverter charger and I did not have time to do that before I set off for the summer. I will do that in a couple months when I have the time. I’m not sure if this was related to the problem or not.

In the meantime, I’m thinking about a manual transfer switch that will allow me to switch over from the inverter to shore power. Anybody have any suggestions? I just want a simple 30 amp main transfer switch. I can let the house panel handle the individual circuits. I did some quick googling and haven’t found any really great options. I wondered if anybody else has done something similar and had a suggestion.

Thanks

 

[Grumpy]

I was thinking Amazon, but that only switches the power side and not the ground.

 

[FloHauler]

I was thinking Amazon, but that only switches the power side and not the ground.

I’ve been looking at the Chinesium on Amazon. Lots of it looks sketchy. If anyone has experience with anything decent, I’d appreciate hearing about good options.

 

[FloHauler]

Ordered this off Amazon.

Someone installed it in an RV as I intend to.

Also got a copy of the distribution panel schematic from Jayco on this morning. (They have been so helpful).

Im headed to higher altitudes and lower temps, so I won’t be needing the AC for a while. Should get this installed next week after the parts catch up to me.

 

[Grumpy]

Ordered this off Amazon.

Someone installed it in an RV as I intend to.

I saw that but missed the "8 terminal". Hope it works.

 

[Kevin Cooper]

This was my original post. Do not do this! See responses below this post!



Im not sure why you power went out! Does the inverter not have a built in ATS that defaults to closed for shore power?
I was going to suggest this switch because of its higher ratings and it comes with an enclosure.
KEYMOO 63A Rotary Changeover Switch. Amazon.com
But, then I saw your post. What you have will work, but you must put it into an enclosure.
I get the feeling you already know how to do this, but others may not.
Since I do not know if you have a generator, I do not know if you have an ATS in your system. Either way, the switch will need to be connected with shore/gen power and inverter power and output to the electrical panel.
This device should be used to connect/disconnect the “hot” only.
Do not connect the neutrals to the switch. Connect them all together inside the enclosure. The reason is, if you switch the neutral, you are creating what is called a seperately derived system, which changes how grounding is done.
Maybe not a huge difference, but my philosophy as an electrical designer was KISS method. Keep It Simple Stupid.
Best wishes

 

[craigav]

I would be very careful with using such a switch, it is likely smaller than you expect and the seller doesn't provide much information regarding the ratings. For sure if you use this then a metal grounded enclosure is important, however I wouldn't use this and instead I would use a 30A automatic transfer switch which is common for RV's and can automatically connect to the shore power whenever it is available, no manual lever switching needed. ~CA

Regarding the ratings, where it states Ie: 380v / 1.5A that means that is the limit for switching, 1.5 amps and up to 380V, being generous you may could switch 4~5 amp at 120v but you also may encounter what you see in the image. Also, the 32A rating is 'ith" which is a heat rating, meaning that if you don't ever switch the switch with the power on, then the switch will not (should not) melt down up to 32 amps (if you trust them). Bottom line, this is not a good switch. Also to note the 63A switch Kevin mentioned above would be a better choice although I couldn't read the actual ratings of the switch and I suspect it can't "switch" much more than the 32A switch (perhaps double though, or 3A @ 380v). In any case, if you use this design switch, be sure all the power is off when switching and place the switch inside of a grounded metal enclosure.



Read the neg comments and there are quite a few similar reports.

 

[Kevin Cooper]

After reviewing the AC15 standard as on the label pointed out by Craig, I would absolutely not install either switch in my RV. The AC15 rating is a standard to switch loads greater than 72 watts. These switches are designed to be used as a control to operate coils of contactors. They are not power rated switches. This means, every time connected load is switched there will most likely be damage done to the contacts within the switch.
The only place this showed up was in the picture of the label. Not in the documentation anywhere.

This is a 32 ampere rated transfer switch that you should consider.

 

[FloHauler]

Thanks guys. I’ll look at it in more detail when it arrives. If it’s not sufficient, I’ll develop a plan B. I had some of the same questions when I was reading the specs. Thanks for the added info.

 

[FloHauler]

This was my original post. Do not do this! See responses below this post!



Im not sure why you power went out! Does the inverter not have a built in ATS that defaults to closed for shore power?
I was going to suggest this switch because of its higher ratings and it comes with an enclosure.
KEYMOO 63A Rotary Changeover Switch. Amazon.com
But, then I saw your post. What you have will work, but you must put it into an enclosure.
I get the feeling you already know how to do this, but others may not.
Since I do not know if you have a generator, I do not know if you have an ATS in your system. Either way, the switch will need to be connected with shore/gen power and inverter power and output to the electrical panel.
This device should be used to connect/disconnect the “hot” only.
Do not connect the neutrals to the switch. Connect them all together inside the enclosure. The reason is, if you switch the neutral, you are creating what is called a seperately derived system, which changes how grounding is done.
Maybe not a huge difference, but my philosophy as an electrical designer was KISS method. Keep It Simple Stupid.
Best wishes

The short answer is there is no transfer switch. The shore power is charging the batteries and the inverter is supplying all 120v. I inherited this and other issues and have been working through them. This is a new one. One more thing to resolve.

 

[Kevin Cooper]

Oops! It looks like I didn’t put in the link for the transfer switch.
Chtaixi Manual Transfer Switch, 32 Amp 120V/240V AC Dual 2-Pole DIN Rail Mount RV Transfer Switch, Single-Side Interlock Circuit Breaker MTS D2P C32 Amazon.com
I like this one better
Dual Power Manual Transfer Switch, 2Pcs 2-Pole 32 Amp Circuit Breakers with Single-Side Slide Lock, DIN Rail Included, Ideal for Industrial and Home Use Amazon.com
For some reason, I thought most inverters had internal transfer switch and was connected to 120v too. But I don’t think that is the case here. BTW, that is a very nice inverter.

 

[FloHauler]

Oops! It looks like I didn’t put in the link for the transfer switch.
Chtaixi Manual Transfer Switch, 32 Amp 120V/240V AC Dual 2-Pole DIN Rail Mount RV Transfer Switch, Single-Side Interlock Circuit Breaker MTS D2P C32 Amazon.com
I like this one better
Dual Power Manual Transfer Switch, 2Pcs 2-Pole 32 Amp Circuit Breakers with Single-Side Slide Lock, DIN Rail Included, Ideal for Industrial and Home Use Amazon.com
For some reason, I thought most inverters had internal transfer switch and was connected to 120v too. But I don’t think that is the case here. BTW, that is a very nice inverter.

Thanks, again, and thanks for finding the alternatives. I didn’t find that one when I searched, but I just ordered it and will return the original order.

I haven’t seen that dual breaker setup in a DIN rail, but I like it. It functions like the isolator bracket I have for my Square D panel at the house. I ordered the version with the mounting kit.

The inverter is an Aims PICOGLF30W12V120VR. It is 12v/120v 50/60Hz. The specs are good. Once I get back home I’ll pull it out to see what up with the mystery wire the prior owner installed. In the mean time, if I can get the shore power working directly, it will give me some peace of mind.

 

[FloHauler]

I would be very careful with using such a switch, it is likely smaller than you expect and the seller doesn't provide much information regarding the ratings. For sure if you use this then a metal grounded enclosure is important, however I wouldn't use this and instead I would use a 30A automatic transfer switch which is common for RV's and can automatically connect to the shore power whenever it is available, no manual lever switching needed. ~CA

Regarding the ratings, where it states Ie: 380v / 1.5A that means that is the limit for switching, 1.5 amps and up to 380V, being generous you may could switch 4~5 amp at 120v but you also may encounter what you see in the image. Also, the 32A rating is 'ith" which is a heat rating, meaning that if you don't ever switch the switch with the power on, then the switch will not (should not) melt down up to 32 amps (if you trust them). Bottom line, this is not a good switch. Also to note the 63A switch Kevin mentioned above would be a better choice although I couldn't read the actual ratings of the switch and I suspect it can't "switch" much more than the 32A switch (perhaps double though, or 3A @ 380v). In any case, if you use this design switch, be sure all the power is off when switching and place the switch inside of a grounded metal enclosure.



Read the neg comments and there are quite a few similar reports.

View attachment 1321011

Thanks, Craig. I did read the reviews. It’s always a balancing act.

Appreciate the insights into the specs. Looks like the alternative Kevin found will be a good solution.

 

[FloHauler]

Oops! It looks like I didn’t put in the link for the transfer switch.
Chtaixi Manual Transfer Switch, 32 Amp 120V/240V AC Dual 2-Pole DIN Rail Mount RV Transfer Switch, Single-Side Interlock Circuit Breaker MTS D2P C32 Amazon.com
I like this one better
Dual Power Manual Transfer Switch, 2Pcs 2-Pole 32 Amp Circuit Breakers with Single-Side Slide Lock, DIN Rail Included, Ideal for Industrial and Home Use Amazon.com
For some reason, I thought most inverters had internal transfer switch and was connected to 120v too. But I don’t think that is the case here. BTW, that is a very nice inverter.

So you got me thinking about the transfer capabilities of the unit. The manual says it is supposed to be able to transfer from the utility to batteries. The prior owner has added a mystery wire and switch that indicates output priority between the batteries and external 120v. I don’t know what he did. I reached out previously and he will not respond (after telling me when I bought the trailer to just email any time). Oh well, if I can isolate the two now, it will give me options later.

 

[Kevin Cooper]

Sounds like an electrically operated contactor (some call relay) or transfer switch to me.

 

[FloHauler]

Sounds like an electrically operated contactor (some call relay) or transfer switch to me.

Definitely need a shore power bypass to the inverter. I keep discovering high draw use combinations that it doesn’t like, especially when the electric water heating element or AC are energized.

If I was off grid, I’d be managing loads. But when hooked to shore power I want my conveniences.

 

[craigav]

Definitely need a shore power bypass to the inverter. I keep discovering high draw use combinations that it doesn’t like, especially when the electric water heating element or AC are energized.

If I was off grid, I’d be managing loads. But when hooked to shore power I want my conveniences.

Just to ask, are you aware that your inverter already has a built-in transfer switch that bypasses the inverter when on shore power? Some of your comments do appear that you are aware or this, but still looking for another transfer switch? ~CA

 

[FloHauler]

Just to ask, are you aware that your inverter already has a built-in transfer switch that bypasses the inverter when on shore power? Some of your comments do appear that you are aware or this, but still looking for another transfer switch? ~CA

Thanks Craig. I’m aware. Unfortunately, I think the prior owner’s modification/addition of what I (not so lovingly) refer to as the “mystery wire” are impacting the transfer capability.

Too big of a project to dive into while I’m traveling. I have to remove a lot of stuff to get the inverter out.

I did talk with a tech at Aims previously. He had no idea why the wire was added. He said if I could send him a pic of where it was attached, he could likely tell me what it was doing. I think ultimately, just removing it is the best course of action.

That said, I would still add the separate transfer switch. It gives me the ability to just bypass all the rest and run solely off shore power. I’m all about backups to the backups.

 

[craigav]

Have you thought through how you are going to wire in the second transfer switch? I can think of a few possibilities however none of what I am thinking is a simple elegant solution. If you put the 2nd transfer switch behind the existing inverter then the inverter would be first inline so if it failed then no power to the transfer switch (RV), if you put the second transfer switch in front of the existing inverter then whenever you switch to bypass the inverter and go to direct shore power then the inverter will think there is no power and start inverting and the output of the inverter will not be happy being combined with the shore power which will destroy the inverter.

In any case, I am with you in regards to not making any changes at this time and instead waiting until you are not RV'ing. ~CA

 

[Kevin Cooper]

For some reason, I’m getting the feeling that the mystery wire was put on and feeds power to the transfer switch to make it stay on battery power by engaging the ATS. If it were me, I would remove the wire and see what happens. If it’s hard to get to the end, have connector ready and cut it.