Two EG4 inverters and combiner box to Reliance 10 Circuit transfer switch

[Little Birch Mike]

RE Will's video on combining two EG4 6000xp inverters into a combiner box -
I have an ancient 200 amp breaker box to which I am adding the Reliance 10 Circuit transfer switch. The switch has a 30 amp inlet that can be powered by the output of a 30 amp generator (mine is a Champion 100520, 8750 surge/7000 continuous, < 3% harmonic distortion).
I may, or may not, need to combine two EG4 6000XP inverters. My intent is emergency backup for a full size refrigerator rated at 877 watts, 1000 watt microwave, router, LCD tv, several LED bulbs, and a 40 gallon AO electric hot water heater. From what I've been able to gather, the water heater may draw up to 4500 watts.
I'd like to use the Eg4 6000xp with a 30 amp cord as the AC out directly to the transfer switch.
Question #1- if only powering the refrigerator and the hot water heater, will one EG4 6000xp unit have enough capacity to do so, using two 48v server rack batteries?
Question #2- If two EG4 6000xp inverters are necessary, would their combined output exceed the 30 amp limit of the transfer switch? I understand that the combiner box has two separate 240 volt inputs. But what is coming OUT of the combiner box, especially the amps? Would they exceed the 30 amp limit of the transfer switch?
Sorry if these questions have been answered elsewhere. I'm a newbie at all of this, and would appreciate any advice before I blow up my house. Many thanks!

 

[TM48]

Have you considered one 12000xp? Same power as two 6000s and you wouldn't overload the inverter. Plus less wiring and less expensive than two 6000s.

Your refrigerator will only draw 877w when in defrost. Even a 25 cf refrig runs at ~145w. Your loads will however exceed at times what one 6000 can produce.

What are you trying to accomplish with the transfer switch? Do you intend to switch between inverter and grid power? Or is this between your generator and the inverter? Do you intend to use the gen port or use it as a smart port? Drawing out what you have in mind would be helpful.

 

[Little Birch Mike]

All excellent questions. The transfer switch is immediately adjacent to the breaker box. It's sole purpose is to allow critical circuits to be used when the grid is down. Our home is very rural and we're often the last folks to get power restored after a storm.
The transfer switch includes a 30 amp double pole breaker in its first two circuits and the rest are 15 or 20 amp breakers. I'm going to use the 30 amp double pole breaker for my hot water heater. The rest of the circuits will be single pole. Kitchen is all on one breaker - frig, microwave, dishwasher. That seems a little sketchy to me, but I didn't wire the place. I can definitely omit the dishwasher and probably the microwave in a grid down situation.
To further complicate matters, almost every breaker in my panel is 30 amps! Why the wiring hasn't already melted is beyond me. I'm assuming 12 gauge wiring, but I'm going to check all outlets as well as the wiring entering the breaker box to confirm this, then replace the 30 amp breakers with 20 amp. We bought the house from a relative, who never changed the breakers, so it's been this way for many years. Still, a dangerous situation, I think, and one I'm going to fix with several 20 amp breakers.
When breakers are properly sized and transfer switch installed, I'll use a 30 amp power cord directly from the generator (through a window - tiny notch for the wire cut out from a pool noodle to keep cold and CO out) to the inlet receptacle on the transfer switch to power critical circuits when the grid is down. (I could mount the inlet receptacle on the outside of the house, and not need the window at all, but then I wouldn't be able to hook up the 6000xp, which will be inside the house.) I think, with careful management of what is switched on, as well as what ISN'T switched on, the generator's 7000 continuous watts will be sufficient. But that's a noisy generator running 24 hours a day. Noise isn't really an issue - only one close neighbor, whose generator runs constantly during an outage.
What I'd like is to use the 6000xp (or 12000xp) to run all loads mentioned (again, not all used at the same time) for about 24 hours or so, then recharge the server rack batteries during the day with the generator. Probably use an external 48v charger to accomplish this.
Solar panels, maybe, but later. Right now, just trying to achieve 24 hours of backup that can be recharged each day.
Sorry this is so long. I do appreciate your assistance!

 

[Little Birch Mike]

Link to the transfer switch - 310C Pro/Tran2 30-Amp 10-Circuit 2 Manual Transfer Switch https://a.co/d/fAQ9t7D

 

[TM48]

It makes more sense now. A small load center (~$50) could be used as a transfer switch to allow permanent wiring to the transfer switch instead of a loose wire plug arrangement. Two breakers and a generator interlock would control the source.
As far as the recharging of the batteries it would be cheaper to let grid recharge the batts than the generator unless of course the grid is down. Noise is the main reason I elected to install a solar system. I HATE listening to a droning generator plus in my case in the aftermath of a hurricane fuel rapidly becomes an issue.

Your electrical system is a little odd with the 30a breakers but it may be wired with 10 ga. Of course a typical duplex outlet is only good for 15a. Most of your loads are discretionary so you could probably could squeeze by with one 6000. I'd recommend you get a kill-a-watt and record your actual usage. This is really important for battery sizing. I retrofitted 3500 watt elements to my WH to reduce peak loads but ultimately choose to go with two 6000s because the loads would have maxed one out. In my case it was the right decision as I added much more later.

 

[Little Birch Mike]

It makes more sense now. A small load center (~$50) could be used as a transfer switch to allow permanent wiring to the transfer switch instead of a loose wire plug arrangement. Two breakers and a generator interlock would control the source.
As far as the recharging of the batteries it would be cheaper to let grid recharge the batts than the generator unless of course the grid is down. Noise is the main reason I elected to install a solar system. I HATE listening to a droning generator plus in my case in the aftermath of a hurricane fuel rapidly becomes an issue.

Your electrical system is a little odd with the 30a breakers but it may be wired with 10 ga. Of course a typical duplex outlet is only good for 15a. Most of your loads are discretionary so you could probably could squeeze by with one 6000. I'd recommend you get a kill-a-watt and record your actual usage. This is really important for battery sizing. I retrofitted 3500 watt elements to my WH to reduce peak loads but ultimately choose to go with two 6000s because the loads would have maxed one out. In my case it was the right decision as I added much more later.

Thank you so much. I'll definitely use the kill-a-watt meter to determine my loads. But if I combine two 6000xps or use a 12000xp, one question remains -
Question #2- If two EG4 6000xp inverters are necessary, would their combined output exceed the 30 amp limit of the transfer switch? I understand that the combiner box has two separate 240 volt inputs. But what is coming OUT of the combiner box, especially the amps? Would they exceed the 30 amp limit of the transfer switch?

 

[TM48]

Yes potentially the output could exceed the ratings of the transfer switch. Reliance Controls does sell a 15k watt model however which should allow full power operation. Their A500 series is 50 amp.

 

[Little Birch Mike]

Thanks again. I really appreciate your help!