DIY Home Battery Backup System Question (EG4 6500EX + Transfer Switch

[Milli42]

Hi! I'm looking to create some backup power for our home. I'm planning on starting off with just backing up critical loads with the EG4 6500EX + EG4 PowerPro Battery (14.3kwh). My home is grid tied, but I want this system to power the main parts of my home when the power goes out (only 120V appliances/lights..etc)

My question is, I wanted to utilize a 10 circuit transfer switch to keep it easy to move from grid to battery, but the transfer switch I'm looking at: https://www.homedepot.com/p/Relianc...p-Manual-Transfer-Switch-Kit-310CRK/205793178 is meant for a generator input. Is there a safe way to have the EG4 6500EX inverter feed the power directly into this transfer switch?

 

[ojames600]

Hi! I'm looking to create some backup power for our home. I'm planning on starting off with just backing up critical loads with the EG4 6500EX + EG4 PowerPro Battery (14.3kwh). My home is grid tied, but I want this system to power the main parts of my home when the power goes out (only 120V appliances/lights..etc)

My question is, I wanted to utilize a 10 circuit transfer switch to keep it easy to move from grid to battery, but the transfer switch I'm looking at: https://www.homedepot.com/p/Relianc...p-Manual-Transfer-Switch-Kit-310CRK/205793178 is meant for a generator input. Is there a safe way to have the EG4 6500EX inverter feed the power directly into this transfer switch?

I have the same setup, I wired the EG4 directly to the Transfer switch, you will not need the generator connectors.

 

[Tripplett]

I want to do this as well - move half a dozen circuits to a transfer switch or critical load sub panel while still powering the other half of the house from the mains. I also want to connect the inverter to the mains for battery charging on back to back cloudy days ( “pass through”)

Do these transfer switches also transfer the neutral or just the hot? I thought I saw someone say it was just the hot legs with a neutral bus back to the main panel. So if you are actively powering half your house from the grid and the other half of the house from the inverter (through the transfer switch & still using the grid’s neutral) is that ok?

 

[Daddio7]

I read somewhere to make sure the transfer switch transfers the neutral also. I do not see anything good that can come from having a connection to grid power back feeding to your inverters.

 

[ojames600]

I read somewhere to make sure the transfer switch transfers the neutral also. I do not see anything good that can come from having a connection to grid power back feeding to your inverters.

The Transfer switch does connect to the neutral bar. Reason for connecting the inverters to grid is to charge battery during long clouds days and also for my time of use plan where I can charge for cheap at night.

 

[Tripplett]

The Transfer switch does connect to the neutral bar. Reason for connecting the inverters to grid is to charge battery during long clouds days and also for my time of use plan where I can charge for cheap at night. View attachment 175064

Right, so doesn’t that pose a problem if you have grid power AND generator/inverter power both on and connected to the same neutral?

 

[Milli42]

The Transfer switch does connect to the neutral bar. Reason for connecting the inverters to grid is to charge battery during long clouds days and also for my time of use plan where I can charge for cheap at night. View attachment 175064

Thanks for the reply and your diagram is exactly what I'm hoping to achieve. I'm curious on @Tripplett comment as well. Since I plan to have both the "generator" and grid power on and just have a few circuits on "gen" power only, is there an issue because of the shared neutral (I'm assuming it's shared because it connects to the main panel)?

 

[ojames600]

Thanks for the reply and your diagram is exactly what I'm hoping to achieve. I'm curious on @Tripplett comment as well. Since I plan to have both the "generator" and grid power on and just have a few circuits on "gen" power only, is there an issue because of the shared neutral?

I am awaiting an answer also on the Shared Neutral before I flip the switch ?

 

[Capt Bill]

Hi! I'm looking to create some backup power for our home. I'm planning on starting off with just backing up critical loads with the EG4 6500EX + EG4 PowerPro Battery (14.3kwh). My home is grid tied, but I want this system to power the main parts of my home when the power goes out (only 120V appliances/lights..etc)

My question is, I wanted to utilize a 10 circuit transfer switch to keep it easy to move from grid to battery, but the transfer switch I'm looking at: https://www.homedepot.com/p/Relianc...p-Manual-Transfer-Switch-Kit-310CRK/205793178 is meant for a generator input. Is there a safe way to have the EG4 6500EX inverter feed the power directly into this transfer switch?

1) I just wired up the smaller $310 Reliance 30 Amp Transfer switch at my girlfriend's house (an awesome option), and modified the IN plug and connected wiring for 120 vac Input, instead of its' designed 240 vac split phase IN. ... This will soon be powered a DIY 15.6 kWh of LiFePO4 Battery Powered Backup Wagon (I recently built) connected to a removable table top with an EG4- 3000 unit for power to the transfer switch plug. I have confirmed a 2000 watt inverter generator works for powering that Transfer Switch, and the essential home circuits I wired to it. That transfer switch box alone, when wired properly, will make huge difference when grid goes off. I also confirmed inverter generator to EG4 works for battery charging cycles from the EG4's internal battery charger. ... For Safety; I am making sure my AC plugs and extension cords ... in and out ... are all rated for 30 amps (that smaller extension cord in picture was just for initial testing). I also put a small breaker box with a 30 amp breaker in between the EG4- 3000 and transfer switch Input; & installed a 15 amp breaker for wires to the 120v outlet box (pictured); PLUS I have made sure all my DC Circuit Wiring is properly sized with proper Circuit Breaker; plus (for the project) I installed an additional Fast Fuse Protect.

I am excited to be hooking this up this power supply to that Transfer Switch Circuit Breaker Box this weekend. That will be followed by my thorough testing of its' abilities; initially without Solar input. I had some EG4 configuration challenges that revealed some EG4 Quirks (for lack of a better word); that required my experimenting with settings options, ... to find my work arounds. ... Glad to find this tread topic. I will write more about my experiences later. & ... here's a few pictures. ????

 

[Redflyer]

I did that very project last summer.

I used a solar subpanel, then power the 10 circuit Reliance panel thru a circuit breaker. The transfer switch just breaks the hot in the main house panel. There are alot wires to deal with, but it works really well.

The Home Depot link is a little pricey. I see the same unit on Amazon for $399. Just leave the generator cover on the front and you'll be good to go.

I love the flexiblity of powering a circuit off either solar or the grid. The only downside is.....it's not automatic in any way, so someone has to be there to adjust as needed.

I have the first two slots running 240v for my pool pump, the others are selected circuits from the house. Fridge on one, Chest freezer, etc. The system has worked flawlessly since I threw the switch in early June.

 

[Capt Bill]

I did that very project last summer.

I used a solar subpanel, then power the 10 circuit Reliance panel thru a circuit breaker. The transfer switch just breaks the hot in the main house panel. There are alot wires to deal with, but it works really well.

The Home Depot link is a little pricey. I see the same unit on Amazon for $399. Just leave the generator cover on the front and you'll be good to go.

I love the flexiblity of powering a circuit off either solar or the grid. The only downside is.....it's not automatic in any way, so someone has to be there to adjust as needed.

I have the first two slots running 240v for my pool pump, the others are selected circuits from the house. Fridge on one, Chest freezer, etc. The system has worked flawlessly since I threw the switch in early June.

I would get the Reliance 10 circuit breaker box transfer switch ... if for my house, ... and run 240 vac split phase. For my gal's house, I used the Reliance 6 Circuit Box & reconfigured the IN Plug and wiring for 30 Amps * 120Vac IN. I also changed the 240vac 20 amp double breaker to two separate breakers / one 120vac 30 amp, and one 20 amp breaker making for 6 x 120vac circuit breakers. Only those two circuits wired for the 240vac Double Breaker have 10 awg wire that can handle 30 amps/ & the other 4 breakers have 12 awg wire. The Supplied Directions were Good. I now understand more how all this works from my DIY install, and Like the Reliance brand. ... Learning More, including via my DIY projects, ... All The Time. :+)

 

[OffGridForGood]

If you connect an AIO inverter to a Reliance tied to a grid panel, and the AIO does a N-G bond during inverting mode, but the grid panel provides a N-G bond via the main panel you now have a ground loop.
Best to check the AIO and how it handles N-G bonding, especially if the AIO is also fed by the utility for battery recharging situation.

 

[Capt Bill]

I would get the 10 circuit breaker box transfer switch ... if for my house, ... and run 240 vac split phase. For this 6 Circuit Box on this project, I reconfigure IN Plug and wiring for 120Vac IN, plus changed the 240vac 20 amp double breaker to two separate breakers / one 120vac 30 amp, and one 20 amp breaker making for 6 x 120vac circuit breakers. Only those two circuits wired for the 240vac Double Breaker have 10 awg wire that can handle 30 amps/ & the other 4 breakers have 12 awg wire. The Supplied Directions were Good. I now understand more how all this works from my DIY install. ... The last 30 amp breaker circuit I will wire from that transfer box is for a GE motor powered 3/4 hp water booster pump that is currently wired for 240vac, with motor config option for 120Vac, at twice the amps, and even more for surge start up.

Re: Automatic: I believe when I get this Battery Wagon w EG4 ... hooked up to its' 30 Amp In and Out Plugs. ... It will function in Automatic Mode by my configuring for 120vac to pass through from grid to power the EG4's AC Out going to the essential home circuits; w the Transfer box switched from Grid IN to GEN IN; ... & left in this mode for automatic. ... Then when grid goes off, my inital testing shows the battery power take over to power the GEN IN to the Essential House Circuits; ... AND ALSO ... When Grid Returns ... The Grid Powers All the Circuits switched to GEN in Transfer Box; PLUS automatically initiates a Battery Charge Cycle (unless EG4 3000 is configured for power saving mode ... mine needed a work around ... more on that later). Configured Grid powered battery charge amps need to be low enough to allow EG4's 3000 Watt ByPass Capability with enough Watts left over for the Essential Circuits. My First Test Cycles after its' new home hook up ... soon .. will be powering all the essential circuits (currently 5/ without 30 Amp Breaker to water pump) that I have already wired to this Transfer box, Leave it switched to GEN IN ... watch Grid power the Home's Essential Circuits working properly; Then Switch The AC 30 Amp Breaker that goes in Main Panel, That is Powering the EG4 ... to OFF, and I will get to witness how long that 15.6 kWh of LiFePO4 Battery Power lasts. From kWh of last monthly utility bill when being frugal, I estimate the Battery could power All Essential Circuits for Two Plus Days. I look forward to what my next Testing Cycle Reveals.

Re Wiring an EG4 or any all in one "Directly" to a Transfer Box Switch, without In and Out plugs: ... I prefer a wheeled setup with 30 Amp Cord and Plugs for the obvious documentation that this is a Portable AC Power Backup Unit (with No Way I currently know about; for needing a Building Permit and Inspection. Being this is for a house I do not own, and I am becoming Tech Support for a friend who paid for the material costs only (which was about $3500 including transfer switch box); ... This Portable Option enhances my comfort level; ... and is Great for easy transport options (that might someday power a music concert at the park, ... for education attention about home power grid back up options). I will be billing for consultation and configuration on my next setup; with goal of help neighbors while staying in my easy going retired options mode.

Re my wiring of that Circuit Breaker Transfer Box: I told my friend I can Do All the Details Properly (even found a 12 awg wire on a 30 amp breaker I updated to 10 awg wire) ... AND if she ever wanted or needed to get a Permit for this Transfer Switch set up; like for possibly down the line, if selling the house?, ... she could hire a Licensed Electrician for an inspection and hoop jumping for that. I am confident of my details on 240 vac Circuit Breaker Panels with a history of doing all the AC Wiring on 3 DIY built Houses (two in Northern California via Building Plans I drew up myself for the Permits. My mechanic shop back in the 80s is also part of my electrical and diagnosis background. This is currently a fun and engaging hobby. I am currently retired. I like help friends. AND ... I Enjoy Learning More, including via my DIY projects, ... All The Time. :+)

Here's a Nov 7 UPDATE: I have the EG4 3000 EHV-48 hooked up to Essential Home Electrical Circuits ... functioning in Automatic Battery Home Backup Power mode. In my view, it is working great at routing 25 - 30 Amps AC bypassed through the EG4 to the essential circuit wired via that Transfer Switch Box "left in Generator IN mode" (w Transfer Switch above breakers switched to "GEN" input, ... vs clicked to OFF @ middle position; or to the Grid IN mode). When the Grid goes down or is switched off; the Battery to AC Power immediately takes over automatically supplying AC to the Essential Home Electrical Circuits; ... and When the Grid Returns, This Set Up Powers the AC Loads, PLUS initiates a Battery Charging Cycle, all AUTOMATICALLY. There is the Option to leave the Battery Wagon sitting with EG4 inverter & JK BMS in OFF mode, and then turn it all on for Grid Off Cycle, and switch all to Gen IN mode manually too. ... I believe the Battery Only Mode for Automatic AC Power that I put this EG4 unit in Without Solar PV Input, via my configurations, ... is not what this unit was intended for; BUT this is Definitely a Doable Option. I Do Notice "Power Saving Mode" must remain Disabled. I have some other info for ya later. Here's a picture of my install at my girlfriend's house. Building this and setting this up for somebody else who does not undertand what AC electrical amps are, and is still on a flip phone on purpose, ... engaged me in much more testing cycles, plus details for safety, ... than If I made this for my personal use. The JK BMS 4.3 LCD Screen was a must for the info it shows. ... I am gona write up more details about my learning experiences, including about some tech support dialogs I got in with Signature Solar ... in a thread of its own ... later. Best Wishes in your DIY and all other Endeavors from me ... Capt Bill

ADDED NOTE: My gal just asked me how much does it cost on her utility bill to leave the Battery Wagon ON in Automatic Mode, vs OFF and requiring manual switching. She wondered if auto mode (with EG4 fan, and JK BMS LCD lite up / configured always on: might add $10/ mo. I told her likely less than $1/mo. My later TEST to find out is running in Auto Mode with a Kilo Watt Meter on the AC IN route to EG4, and compare that to AC OUT reading (using two kill a watt meters) might be worth the time, and .. Be Interesting.

I Like this larger kWh Wagon on Auto Mode ... for non techy folks, PLUS ... for Frig and/or Freezer always powered on when gone on longer trips, plus for any security camera set ups, or lights on, and maybe off on cycles to look like somebody is home for security purposes, or for other automated circuits like Auto Lawn or Garden Watering Cycles etc. In Costa Rica I have music from a mp3 player going off at night, & on during day via computer speakers power through a timer (to barely hear at front door, keep the scanning theives away in that neighborhood). There my auto power supply is a 12v deep cycle lead acid based Tripplite 750APS. ... More Later ...

 

[Tripplett]

My gal just asked me how much does it cost on her utility bill to leave the Battery Wagon ON in Automatic Mode, vs OFF and requiring manual switching. She wondered if auto mode (with EG4 fan, and JK BMS LCD lite up / configured always on: might add $10/ mo. I told her likely less than $1/mo.

You can calculate it. The EG4 uses 50w (I believe) if the inverter is running. 50 X 24 hrs X 365 days is 438 kW. I pay 12 cents a kW so that’s $53 a year or $4.38 a month. Much less if the inverter is off or in power save mode - waiting for a load.

edit: I like the cart setup.

 

[Capt Bill]

You can calculate it. The EG4 uses 50w (I believe) if the inverter is running. 50 X 24 hrs X 365 days is 438 kW. I pay 12 cents a kW so that’s $53 a year or $4.38 a month. Much less if the inverter is off or in power save mode - waiting for a load.

edit: I like the cart setup.

Thanks, ...You did it before me ... I just looked up cost per kWh here in Northern California, and saw about $0.20 per kWh for my area. So I get 50 watts x 24 hrs x 30 days = 36 k/wh x $0.20 = $7.20 / month for where I live ( ... More reason to go Solar).