Auto transfer Switch for 240volt 2 phase Application

jkmastro

New Member
Joined
Nov 8, 2021
Messages
4
Hello,

Does anyone know if this unit supports 240 volt 2 phase?

MOES Dual Power Controller 50A 5500 Watt Automatic Transfer Switch for Off Grid Solar Wind System ATS DC 12V 24V 48V AC 110V 220V.​


If not, any suggestions an an alternative? I want to power my office but the mini-split is 240 volt (3 wire) so not sure if that will work with this device.

Any help would be greatly appreciated!

Thanks,
James
 

Ampster

Renewable Energy Hobbyist
Joined
May 3, 2020
Messages
4,643
Location
Kenwood, California
To clarify, North American 240 volt systems are single phase. When 120 volts is pulled off that it is known as split phase. I did not read the specs but if it is designed for North America it should work. 110 220 are older descriptions of the existing 240 volt standard.
 

jkmastro

New Member
Joined
Nov 8, 2021
Messages
4
To clarify, North American 240 volt systems are single phase. When 120 volts is pulled off that it is known as split phase. I did not read the specs but if it is designed for North America it should work. 110 220 are older descriptions of the existing 240 volt standard.
Thank you. Yes, split phase. Just doesn’t look like there is a place for a 3rd wire. My 240 volt mini split has two hots and a neutral. Any thoughts? Would both hots go in the single port?
 

Ampster

Renewable Energy Hobbyist
Joined
May 3, 2020
Messages
4,643
Location
Kenwood, California
Would both hots go in the single port?
You would have to read the specs for your inverter. Usually the hots are identified as L1 and L2 and N for neutral. Port could mean anything. Your minisplit presumably has some components that must use 120 which is why there is a neutral (3rd wire). There should also be a fourth wire known as ground.
 

Brett V

Solar Addict
Joined
Apr 5, 2021
Messages
252
I'll fathom a guess that 3rd wire to the mini split is a ground, not neutral.
 

jkmastro

New Member
Joined
Nov 8, 2021
Messages
4
Ok, I will check on the mini split.

But was also asking because I was thinking of just running my entire office through the transfer switch.

For example:

50 AMP breaker runs from my main circuit box to a sub panel in my office.

I was thinking to disconnect the wires from the 50 AMP breaker (main circuit box) and run those into the transfer switch as the Load.

Then run from the 50 AMP double
pole breaker (main circuit box) to the commercial power input on the transfer switch. The breaker has 2 hots and a neutral.

Then run my 240 volt split phase inverter into the inverter power input.

But I am wondering if this is possible because the transfer switch does not appear to accept two hots and a netruel.

Does that make sense?
 

jkmastro

New Member
Joined
Nov 8, 2021
Messages
4
You would have to read the specs for your inverter. Usually the hots are identified as L1 and L2 and N for neutral. Port could mean anything. Your minisplit presumably has some components that must use 120 which is why there is a neutral (3rd wire). There should also be a fourth wire known as ground.
Yes. That is correct. L1 L2 a N and a ground. So would L1 and L2 run into the L on the transfer switch? Or is that not possible?
 

Whinny

Solar Addict
Joined
Dec 24, 2020
Messages
350
Transfer switches are also available from RV stores and Home Depot
 
Last edited:

Ampster

Renewable Energy Hobbyist
Joined
May 3, 2020
Messages
4,643
Location
Kenwood, California
So would L1 and L2 run into the L on the transfer switch? Or is that not possible?
Yes is is possible but will be a direct short across L1 and L2 and smoke will escape and sparks may fly. LOL.
My suggestion is that you familiarize youself with some electrical terms. For starters, if it is actually a 240 volt transfer switch, as the title suggests, it should have an L1 and L2, not just one labeled L.
 
Last edited:

mpickus

New Member
Joined
Nov 25, 2020
Messages
24
Hello,

Does anyone know if this unit supports 240 volt 2 phase?

MOES Dual Power Controller 50A 5500 Watt Automatic Transfer Switch for Off Grid Solar Wind System ATS DC 12V 24V 48V AC 110V 220V.​


If not, any suggestions an an alternative? I want to power my office but the mini-split is 240 volt (3 wire) so not sure if that will work with this device.

Any help would be greatly appreciated!

Thanks,
James
 

mpickus

New Member
Joined
Nov 25, 2020
Messages
24
James, I have the same question regarding use of the MOES Dual Power Automatic Transfer Switch but am unclear from the responses to this thread if the answer is clear. I would like to run the output of the transfer switch directly to my (small) house electrical panel but don't see from the connection diagrams that the transfer switch accepts L1 and L2 inputs (from utility power). If this transfer switch won't work, can anyone suggest another one that will???
 

OffGridInTheCity

Solar Addict
Joined
May 23, 2021
Messages
551
Location
Southern Oregon
I use several Progressive 240v/120v @ 50a for my off-grid system. Like this - https://www.amazon.com/Progressive-Dynamics-PD52V-Automatic-Transfer/dp/B003VAWNVK/ref=sr_1_2.
1639418311856.png
I have both cheaper (non-surge) and pricier (surge protection) and I can't tell the difference. I see surge models are not in stock right now.

The (US split phase) neutral is required for the relays to work! I put one near my AC compressor and the wiring from the main panel was 240 + ground only (no neutral). I had to run a 120v neutral for the relays :)
 

mpickus

New Member
Joined
Nov 25, 2020
Messages
24
Would this be an alternative?

Progressive Dynamics PD52V 5200 Series Automatic Transfer Switch - 240 VAC, 50 Amp


It does appear to have L1 and L2 inputs.
Unfortunately it doesn't have some of the cool features of the MOES transfer switch, specifically the ability to switch automatically between utility and inverter power based on monitoring the state of the battery.
 

OffGridInTheCity

Solar Addict
Joined
May 23, 2021
Messages
551
Location
Southern Oregon
Would this be an alternative?

Progressive Dynamics PD52V 5200 Series Automatic Transfer Switch - 240 VAC, 50 Amp

Yes. Here's a link for more detail if it helps - https://www.progressivedyn.com/transfer-switches/

It does appear to have L1 and L2 inputs.
Unfortunately it doesn't have some of the cool features of the MOES transfer switch, specifically the ability to switch automatically between utility and inverter power based on monitoring the state of the battery.
In my system, I turn the inverters on/off by voltage using my Midnite Classic charge controller AUX 1 relay This in turn causes the ATS to switch to Inverter or back to Grid if Inverter is off. Inverter on at 51.5v and off at 49.5v - and settable thru Midnite Classic software to be automatic or I can do it manually etc.
1639419881511.png


My point being (I think) is that the ATS is not the only place to control inverter on/off? just depends on what works for you :)
 

Tecnodave

Solar Addict
Joined
Mar 22, 2021
Messages
762
On a Transfer Switch only the hot wires are switched.......Only L1 and L2 for a U.S. based split phase system.
Neutral IS NOT switched nor does it need to be.

There will be NO CURRENT FLOW between the grid power and solar or generator if ALL THE HOT WIRES are switched.

Correct wiring is to bring all 4 wires ....L1, L2, N , & G from the main panel to the transfer switch
AND all 4 wires.....L1, L2, N , & G from the alternate source to the transfer switch

Neutral wires from both sources go the neutral buss, this must “float” from ground
Ground wires from both sources go to the Ground buss which is grounded to the transfer box

L1 and L2 from the utility go to one side of the transfer switch

L1 and L2 from the alternate source go to the other side of the switch

And I am going to repeat this:

There will be NO CURRENT FLOW between the grid power and solar or generator if ALL THE HOT WIRES are switched.

To be clear my credentials........Industrial Electrical Engineer retired from GeneralElectric
Commercial Electrician......in California....USA
 

Tecnodave

Solar Addict
Joined
Mar 22, 2021
Messages
762
And what I omitted in above post....the output of the transfer switch is wired to the sub panel that the nessecary circuits are wired to
 

mpickus

New Member
Joined
Nov 25, 2020
Messages
24
On a Transfer Switch only the hot wires are switched.......Only L1 and L2 for a U.S. based split phase system.
Neutral IS NOT switched nor does it need to be.

There will be NO CURRENT FLOW between the grid power and solar or generator if ALL THE HOT WIRES are switched.

Correct wiring is to bring all 4 wires ....L1, L2, N , & G from the main panel to the transfer switch
AND all 4 wires.....L1, L2, N , & G from the alternate source to the transfer switch

Neutral wires from both sources go the neutral buss, this must “float” from ground
Ground wires from both sources go to the Ground buss which is grounded to the transfer box

L1 and L2 from the utility go to one side of the transfer switch

L1 and L2 from the alternate source go to the other side of the switch

And I am going to repeat this:

There will be NO CURRENT FLOW between the grid power and solar or generator if ALL THE HOT WIRES are switched.

To be clear my credentials........Industrial Electrical Engineer retired from GeneralElectric
Commercial Electrician......in California....USA
TechnoDave,thanks for your explanation. I still have a question on connecting the 120VAC output of my inverter to a transfer switch. Inverter supplies only one load output lug not L1 and L2. Can the inverter load output be connected to EITHER L1 or L2 on the transfer switch?? That would power only half of the circuits (right??) in my main panel which would actually be fine.
 

Tecnodave

Solar Addict
Joined
Mar 22, 2021
Messages
762
TechnoDave,thanks for your explanation. I still have a question on connecting the 120VAC output of my inverter to a transfer switch. Inverter supplies only one load output lug not L1 and L2. Can the inverter load output be connected to EITHER L1 or L2 on the transfer switch?? That would power only half of the circuits (right??) in my main panel which would actually be fine.
Yes, the 120 volt inverter will only power the leg that you connect it to and only the 120 volt circuits on that phase will be connected OR.....on the input side of the transfer switch connect the 120 volt inverter to both L1 and L2 and all 120 volt circuits will be powered. BUT....the 240 volt circuits will not be powered EXCEPT....some modern 240 volt ranges and dryers will have the controls wired 120 volt only so the display panel will light and turn on but the burner elements will not work as they have the same voltage on both ends. Most will not have a problem with that. Bosch and Meili branded units the controls are 240 volts so they will not light up but some models of GE, RCA Whirlpool, Maytag and other will light up the control panel but motors and heater elements will not work......Some will throw an error code but will not be damaged by this. Clocks may well have to be reset but this is a minor inconvience compared to the poor texans who lost all power during power blackouts. The system left them in the dark for days. I have installed single phase inverter/chargers with batteries and no solar panels for this use in some installations for emergency backup use where solar is not appropiate, some HOA’a will not allow solar, so this will provide some backup capability, especially for those folks who rely on supplemental oxygen to survive.
 
Top