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Automatic UPS / Inverter Connection Diagram to the Home Panel Board

Automatic UPS System Wiring Circuit Diagram (One Live Wire & Ordinary Wiring)

Automatic UPS / Inverter Connections

In case of an emergency breakdown when utility power is unavailable from the power house, we may use an automatic inverter / UPS wiring circuit with batteries to maintain uninterrupted power.

We will show two basic methods of wiring and connection of UPS / Inverter with batteries to the home distribution and main panel board.

  • Auto UPS / Inverter with Two Wires
  • Automatic USP / Inverter Wiring with One Live Wire

Note: To be on safe side, use 6 AWG (7/064″ or 16mm2) cable and wire size to connect the UPS to the main panel board.

Automatic UPS / Inverter Wiring with two Wires.

No rocket science here. Just connect the outgoing Neutral and Live wires to the UPS. Now connect the two outgoing Neutral and Phase wires from UPS / Inverter (As output) to the appliances as shown in fig 1.

Automatic UPS Inverter System Wiring Diagram

UPS / Inverter Wiring with Single Additional Live Wire

As a basic, we know that each load points should be connected through Live (Phase) and Neutral wire to operate normally. In case below, we have already connected the Phase & Neutral (from Power house to the utility pole & Distribution board then) to each electrical appliance i.e. Fans, Light points etc. That’s what we do in our distribution board for home wiring.

Now, according to the UPS connection diagram below, connect an additional wire (Phase) to those appliances where we have already connected Phase and Neutral wires from the power house and distribution board (DB) (i.e., two wires as phase (Live), as shown in the figure below).

There is no need to connect an extra Neutral wire from the UPS since it is already installed and connected beforehand. In simple terms, you only need a live wire to connect to the appliances, as illustrated in Figure 2. Now, the question arises, “Why an extra Phase wire and not a Neutral?” Well, read the following explanation of the circuit’s working and operation to understand the idea.

You may also read:

Click image to enlarge

Automatic UPS Inverter System Wiring Diagram (One Live Wire)
Automatic UPS Inverter System Wiring Diagram (One Live Wire)

Working and Operation of UPS Connection

(1) When utility power is not available from power house

In this case, electric supply will continue through Phase wire (Output of UPS) which is connected to the batteries and UPS and then to electrical appliances (Note that Neutral is already connected). So the first one phase wire which has already connected before UPS installation (i.e. Live Wire from Main board to UPS) would be inactive because power supply is not available from power house. In this case, connected electrical appliances through the live wire from UPS / Inverter consume the stored electrical energy in the batteries without interruption.

Related Tutorials:

(2) When power supply restores from power grid

Then power supply will continue through the Phase wire (Note that Neutral is already connected) which is connected to the UPS from main board (it will charge your battery as well) and then from UPS to connected electrical appliances. So the second one (phase or live wire) which is connected after UPS installation (i.e. One Live Wire from UPS) would be inactive because power supply is not available from UPS and batteries (Because it is Automatic UPS System).

Related Posts:

How to Connect a UPS / Inverter to the Switch Board?

The below fig 3 shows that how to connect a UPS / Inverter with batteries to the Main Distribution Unit for continues power supply in case of the utility power failure.

Additional wiring connection with connected load and appliances for two rooms in home. How to Connect Automatic UPS / Inverter to the Home Supply System?

Click image to enlarge

How to Wire UPS Inverter to the Home Supply
How to connect UPS / inverter to the distribution board?

Wiring Color Code:

We have used Red for Live or Phase , Black for Neutral and Green for Earth Wire in single phase. You may use the specific area codes i.e. IEC – International Electrotechnical Commission (UK, EU etc) or NEC (National Electrical Code [US & Canada] where;


Single Phase 120V AC:

Black = Phase or Line, White = Neutral and Green/Yellow = Earth Conductor


Single Phase 230V AC:

Brown = Phase or Line, Blue = Neutral and Green = Earth Conductor.

General Precautions while playing with Electricity.

  • Disconnect the power source before servicing, repairing or installing electrical equipments.
  • Use the proper cable in size with this simple calculation method ( How to determine the suitable size of cable for Electrical Wiring Installation)
  • Never try to work on electricity without proper guidance and care.
  • Work with electricity only in presence of those persons who has good knowledge and practical work and experience who know how to deal with electricity.
  • Read all the instructions, user manuals, cautions and follow them strictly.
  • Doing your own electrical work is dangerous as well as illegal in some areas.Contact the licensed electrician or the power supply company before practicing any change in electrical wiring connection.
  • The author will not be liable for any losses, injuries, or damages from the display or use of this information or if you try any circuit in wrong format. So please! Be careful because it’s all about electricity and electricity is too dangerous.

Related Posts:

Now If you still facing difficulties or don’t understand the wiring diagram, don’t hesitate to leave a comment or  just check the other related step by step tutorials about UPS / Inverter Wiring Diagrams & Connections with description, and operation.

You may also read other Electrical Wiring Installation Tutorials.

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      1. Hello what could be the possible reason as ,my house light is not working when there is supply from power grid but it works only when we turn on invertor. And inventor also not getting charging with main supply line.

      2. hello,

        i have devices that i only want to turn on when there is no grid power and the inverter is “activated”. how to achieve this?

  1. Dear Wasim Khan<br />I am thankful to you for the UPS diagram on your blog. I have found it perfect for installation of my new UPS with the system.

  2. So as per your diagram we connect only the live wire from the ups output to the loads we want to connect. There is no need to connect the neutral from ups output to the load circuits. My ups was connected like this earlier. But now I have shifted and when i reconnected at new place as before and switch off the main switch to check the attached load doesnot work. I was wondering from where the

    1. Suman@<br />There are more UPS wiring diagrams under the &quot; Electrical Wiring &quot; Tab. ( You should Check)<br />in this case of above diagram, we have connected only live or Phase wire from UPS to the load, because Neutral wire already connected to the load ( from Distribution board) so no need to connect Neutral wire.<br />If you want to connect neutral wire, then Use this method.<br />

    2. I have a doubt on live wire from ups connected to loads.I have two flats on the same building. one flat has single phase supply and an inverter/ UPS connected. I had the second floor also connected with the same UPS with a live wire from UPS. This was done When i had no power supply to the fllat. Now I have separate 3 phase connection for the second floor. I have disconnected the UPS and the charger supply to the battery to avoid any untoward incident. pl suggest suitably

    1. Dear..It is not On-Line…It is One Line…I.e Only Phase or Live Wire..As shown in above circuit diagram

  3. Thanks for the Circuit. I Think, I can install my new UPS alone. But I have one doubt. If my House load is more than the capacity of the UPS means..? <br /><br />UPS will trip..? IF yes, After Electric board power comes, IT will not switch on right.? Then my house will not get power..?<br /><br />Please explain me.

  4. Dear Parthib@ <br />As we know that Inverter should be greater 25% than the total Load<br />Suppose your Load = 800 Watts, than, <br />800 x (25/100) = 200<br />800+200 = 1000 Watts<br />This is the Rating of the UPS (Inverter)<br />So, before installation , Try to calculate the rating of UPS according the load.<br />Secondly@ Can you operate a 500W Motor on 110 W???? So that is the answer.

    1. Thanks for the info,<br /><br />At present.<br /><br />I have 600VA mahindra Powerol Inverter and 150AH Amaron Battery.<br /><br />My full Home load is 4 light and 2 fans and 1 TV.<br /><br />So can i connect this type of wiring.?

  5. I have luminus sinwave invertor, i transfered to a new place , one elctrician came and connected it and it and not working , can u guide how i connect its out put and input in my mainswitch of my house.. shall bgr8ful<br />

    1. I think this is very simple wiring diagram….but you can find more wind diagrams about UPS wiring above in Electrical Wiring Section…

  6. sir i wan to ask that as i successfully installed ups as in your diagram. but can now iwant to use generator can we use same appliance wired for UPs on GENERATOR means live wire plug into generator is it works<br />

      1. Sir I have two type of wiring one for ups and other for Wapda if I plug generator switch in Wapda switch not connected with ups and ups can shutdown then is it all appliance work properly which is. No connection from ups .thanks reply me also on email

  7. Hello sir, i have an pure sine wave 850va inverter and i m using your circuit in which one live wire is connected from inverter/ups output.. my half home appliances runs from directly grid power and half are through inverter and i use the common nutral wire.. now my question is if i switch off the input it will go in backup mode but will it affect my inverter because we use only phase/live from

    1. ok i just saw it and the same thing i done at my home… now my questions are same as above… Pls answer it if you can Thank you for your kind Reply.

    2. Grid Current in inverter Out put socket viva Phase/Live???????? but Why??.. You can use only the above diagram… Or just check in &quot;Electrical Wiring…Home wiring…UPS Installation&quot; Section…

    3. (1). No. This circuit is designed for that specific operation.. So no need to worry. it will work and it will never damage your inverter.<br /><br />(2). Yes! you should do (for safety purpose)<br />

  8. UPS’s are not expensive compared to the rest of a VoIP system, but unless they are budgeted for during the planning process they tend to be overlooked. When the UPS planning is done for the access closets, it is also important to make sure there is enough electrical power to the closets.<br />

  9. i have a problem with the output socket of my inverter, it gives output through left Pin in the socket when connected to mains and then supply changes to right pin when mains off or runs with battery

  10. sir, when i switch off main breaker , my home neutral line getting power. why? we have installed inverter circuit same as above. <br /><br />note:all equipments working as usual for years with same inverter diagram. today simply checked neutral line, and got this problem.

  11. Harish:-sir as per u r diagram the load is more as fans,lights ,chichen ites and ac&#39;s etc…are connected together on only one line…if the incoming power is switched off or shut down the load will drawn the all power charged in battery with in a seconds……so that we hav to drawn another one line for load…..

  12. Respected sir,<br />i have complete UPS system in my house, UPS also charges the battery now i want to connect solar panels to charge the battery. one i/p from battery and other i/p from solar panels, Confused what should i do?<br /><br />Zubair Anwar

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  14. i wanna ask that if the plug attatched to ups is plugged out of ups and put in the socket in main circuit where the charging plug was attatched after removing it??

  15. Thank you very much for the simple connection diagram.<br /><br />But I have doubt. I think UPS is not connected to the Earth wire in this &#39;New Design With One Live Wire&#39;.<br /><br />Is there any way the UPS could be earthed? Does the absence of earthing affect the safety/life of the UPS? Is this important at all?<br /><br />Please reply as I am looking forward to instal a home UPS in the

    1. As you can see that Neutral wire is already connected to all appliances…so no need to connect another Neutral wire… <br />another thing …. That Neutral wire is not for safety purpose..just for completion the circuit..<br />Also you can connect Earth (grounding) wire only with UPS for safety purpose…

      1. Respected sir..
        If we disconnect the mains neutral for the circuit, then how can inverter completes its circuit? Actualy we did not taken the inverters neutral no…

    2. Sorry for irrelevance . Just I was curious with how pre paid electric meters work and specifically how do they know the token entered is the one; is there a connection made with the electricity supplier HQ or they are incorporated with formulas to decipher the tokens or there is another way and in addition how do the remotes work.

  16. Sir one more question, your diagram does not specify what to do with the main phase wire for e.g. if I connect a fan switch to the UPS, the UPS wire is connected to the switch, but what do I do with the existing WAPDA Phase wire that was connected to the fan switch before wiring the fan switch to the UPS? Do I jodo/twist the UPS and WAPDHA Phase together into that fan switch which I mentioned in

    1. Dear Azaan Kaul@<br /><br />As you know, in your case, we had already connected Phase &amp; Neutral (from WAPDA) to Electrical Appliances i.e. Fans, Light points etc… So according the above UPS Connection Diagram…connect an extra wire (phase) to those appliances where we have already connected phase and neutral from (wapda) (two wire as phase with same point). So no need to connect Neutral

    2. Thanks a lot Wasim Sir! Can you also provide a tutorial on how to install tube lights, exhaust fans etc.? Try to put some stuff related to Air conditioning too! Anyways really good website! Simplifies things!

    3. Dear Azaan Kaul<br /><br />We Will try our best,,Stay tune here….<br />And bundle of thanks for appreciation…

  17. sir, diagram is ok. we have 3 phase connection. living hall on phase 1 and bed room on phase 2 and kitchen on 3 phase. if i connect my invertor on one single line from invertor to tubes and fans it will work. when all 3 phase current (grid) fails no problem. my invertor was connected to phase 1` for charging. during night phase 2 (bedroom) power supply from grid fails, how my invertor will

  18. this is for ups but what about only 3 pin invetrer which contain 3 wire in a single cooted plastic cover which are responsible for input or output<br />

  19. Great web site you have got here.. It&#39;s difficult to find <br />excellent writing like yours nowadays. I seriously appreciate people <br />like you! Take care!!<br /><br />Feel free to surf to my weblog <a href="; rel="nofollow">poignées de portes</a>

  20. I hope you may continue to keep in posting new posts thank you for sharing your great experience among us. distribution boards

  21. can i use this diagram to power up an a/c small 200-400 watts refrigerator and a desktop computer?? your answer regarding this is much appreciated. thank you.

  22. can i use this circuit diagram to run a small a/c 200-400 watts refrigerator and a desktop computer? I have 850va pure sine wave inverter.

  23. In my inverter I am getting phase in output in one pin when current is available and it is getting changed to other pin when there is no power…i am confused now which one to use for single wire.. if i interchange the single wire pin my appliances are only working either in power on mode or in power off mode, please help me to correct this prob

    1. I am facing the exact same problem since yesterday after the inverter was taken off and reconnected again. Can someone help? One of the earlier comments suggested to swap the input phase with neutral. I tried that but it didn’t help – the inverter doesn’t recognize the input if done that way. Am I doing something wrong?

  24. Dear author….u said while supply available from grid the pwr comes from main to ups to charge battery….then after ups to appliances.. what u said at starting is 2nd phase wire i.e from ups is inactive if it is inactive how pwr reaches from main to appliances…i asked because there os no direct phase connection from main to appliances

  25. hello sir,
    you have a marvellous site here. I’ve learnt quite a bit, almost enough to attempt a diy installation of an inverter! I have planned for a 1500va system with 2 batteries. here comes the daft question. I’d like to make it whole house. I’ve no major power hungry equipment. lots of 10 watt LEDs, two laptops, a small set top box with LED TV. I do however plan to get a. induction stove at some point,though there will not be a need to run it off an inverter. almost forgot my question. could I just connect the ups to the fuse panel directly and call it a day, or am I being silly?
    thanks in advance!

  26. Hi my question is when wiring the light switch/point with the UPS and mains wire, in which terminal of the switch do I have to put the UPS wire, is it in the input MAINS PHASE terminal of the switch from where you get the MAINS or the output phase terminal of the switch which is connected directly with the load. Could you please show a diagram if you can?

    In simple words in the pin of the switch in which you put the MAINS phase, do I have to put the UPS wire on that very same MAINS phase pin of the switch, or do I connect the UPS wire to the Output of the Switch, which is directly connected to the load such as fan, light etc.

    Please show a diagram if you can:

    Can you make something like this as a diagram in detail please?

  27. Sir, if we gives input supply to the inverter which is charge the battry but same condition output wire also connected to same point that is live wire…… meanxe both have current supply……. So in that position can inverter will work or not?

  28. when power cuts how the power from inverter can’t go back to power grid i.e from service wire to electric poles and poles to transformer ….
    how inverter wiring prevents power to go back from house to electric poles and vice versa when no power supply from grid….
    other question brother how it take neutral when i unplug inverter from socket…
    how neutral will take as no need of neutral wiring when we connect only phase wiring to the output socket in inverter…..
    please explain me no need of neutral wiring and how power can’t pass from inverter to electric poles ,to the transformer……
    I am waiting for your reply…

  29. Hi Sir,

    could you please confirm whether my inverter (Microtec 850VA EB Model) is compatible with the above diagram.

    Thanks and awaiting reply.

  30. Thank you so much for the selfless service of providing such a perfect diagram, which can be understood and applied even by layman.

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  32. Very nice circuit diagram Wasim….it helped me in installation of inverter…please put provision of bypass also if we dont want to connect inverter circuit to heavy load appliances like AC, fridge…Just tell me for bypassing i m using direct live connection to appliances bypassing inverter but nonlive wire common…is it ok??

  33. output phase is getting change on my UPS. when main power will not cutoff then its gives phase from right side, after cutoff phase will change on left side pin. why this is happening??? please sir give me the reason and solution off it. thank you

  34. Hi,

    When power house goes off & my inverter is connected with common neutral (Single line wire) then how inverter supplies power to load as both phase & neutral from power house got disconnected & how circuit will complete in this case?

  35. AOA. I would like your help with a problem I have recently encountered with my UPS used at home. Yesterday, the UPS began to switch from AC Charging mode to Battery mode repeatedly and electricity started fluctuating with it. I thought there was something wrong with its input, so I changed the socket to which UPS is connected to, and installed a new one. As soon I connected my UPS to the AC input, immediately there was an electrical surge and then my UPS failed to function after that. Now after the replacement of MOSFETs I got my UPS working but when I connected to the input again my UPS stopped working immediately after that. Please any help me. I would be grateful!

      1. can we connect live wire from grid as well as ups to the same load… I want llights should be ON on both grid n ups…plz guid..

  36. Hi I have connected mu UPS to my lights circuit breaker and one plug circuit breaker. During load shedding it worked for an hour and half and then tripped. There was a red light with a continuous beep. When the power (load-shedding) was restored I was not able to put my lights on nor was there any power going to the on plug circuit. I have been told that I must unplug my three pin from the UPS and plug into any other plug point for my lights to work on Eskom power. Is there any other way.


  37. Our UPS is exact with this diagram at our home.
    when we switch on electric water pump motor, ups behaves as WAPDA main light is off. and starts showing to dischargin (i.e. there is no light incoming to ups )

    Same case for complete discharging and suddenly light comes, we on fans connected with UPS. UPS then again showing offline (even main WAPDA light is present)

  38. Please let me know a dealer in Chennai who will undertake to carry out the installation of an automatic UPS System for my home use, as per the diagram that you have published.
    thanks and regards.

  39. Hi thanks allot, i have a question if we want to connect invertor in a home which has three phase connection, then what will the automatic circuit diagram

  40. How to connect a switch board to both inverter and main line .when power is not available then inverter use and power is available then power use.

  41. This is some what useful but still don.t understand.
    I have inverter connection in my home ,when raw power goes down,inverter come up automatically.
    When raw power is there it will show charging.
    I want to know below
    When i remove power plug to inverter from raw power,all the power is going down.

    after battery fully charges ,i want to remove charging to battery.
    How can i do this,need immediate help

  42. I have APC bx600ci-in ups (600v-300w) & it is old while changing battery I got electric shock from battery wire, even I have tested with Tester itcis showing current in battery wires when it is charging…itvis suppose to be DC vote then why I am getting shock while it problem with ups or itvis normal & I’m trying to connect external battery what max amp of battery I can connect to UPS..

    thaks in advance…

  43. I have APC bx600ci-in ups (600v-300w) & it is 3year old , while changing battery I got electric shock from battery wire, even I have tested with Tester it is showing current in battery wires, when it is charging…it is suppose to be DC volt then why I am getting shock while it problem with ups or is it normal & I’m trying to connect external battery what max amp of battery I can connect to UPS..

    thaks in advance…

  44. UPS not working during load shading. I’ using neutral directly from main supply and controlling phase from UPS. It works efficiently when main supply is available but when main supply breakdown, UPS also get off.

    Please advise your precious opinion.

    1. It looks like your Phase is not connected to the UPS as well. When Supply is off, Make sure the Phase from UPS is connected to the load as shown in the fig above.

  45. Sir,
    I am asking some of the electrians in my area, most of them are not recommend the Method as they said it will be not safe because of common neutral line as it will produce inverter neutral feedback which can cause severe damage.
    Is it true?

  46. very informative and helpfull . but i have a question here
    for two out put wiring for UPS .
    can the neutral will be common…. i mean if i use a single point for neutral IN for UPS and the neutral Out from UPS also attach to that point . will it cause any problem or not ?

  47. In the one live wire connection, I understand that we’re not taking the neutral from the inverter output(because the neutral is connected to supply neutral). But if there’s a power failure, the devices won’t get neutral connection, right? Then how will this work?

      1. But there is only one wire running from the output of the inverter to the appliances, right? And one end of the appliances is connected to the neutral,(which is open , in case of a fault). The appliance needs phase and neutral, right?

  48. Very nice information. Its highly appreciated.
    BUT i need a guideline that i have one load output wire from UPS. My electrician has made a change now that he joined two wires (Red and Black) with that UPS load output wire. He attached one wire (Red) with MCB breaker (for home load) and other wire (black) with Neutral main wire. Now currently, my single UPS output wire has both Neutral and phase joined with each other.
    Is it fine?
    Previously, there was only one wire as home load.

    1. It seems like that he made a change to UPS by extracting neutral output wire as well . so currently your UPS have load(red) out put and neutral(black) out put . am i right ?
      if i am right then load (red) wire from ups goes in to breaker and neutral (black) goes to the neutral wire , which is totally fine.
      or it will be easy if you upload any pic of the wiring …..

  49. Aoa
    Dear how are you??
    I want to know about solar system installation of 2000watt load capacity with 24v battery charging.. how can I do it

  50. Please I would like to in the one live common neutral connection, when the utility power is back is the load using utility while the battery is charging

  51. I want to know
    is it possible to connect 2 or more inverters in parallel? In order to supply differents loads sharing the neutral cable.

  52. Why is the black wire connected before RCD in the last diagram. I think it should be connected after the RCD? I also think the power Line from the utility pole i.e. the live wire must be connected to the common busbar segment? let me know if i am wrong? Thank You for the awesome post…

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