EG4 6000XP PV hook up

[johnbrutovsky@hotmail.]

Excuse me if this has been asked before. I did a quick search of the forums and did not find anything. My question is this. My previous inverter was a EG4 6000EX with a single PV input. That unit failed last week. ( that's a separate post ). I may be replacing it with a EG4 6000XP. In the past I have seen the EG4 6000EX top out during the summer between 6500 and 7000 watts of PV input ( high noon ). My set up is that I have three strings on the roof all connected to a roof top mounted combiner box that has a single output to the garage where it was connected to the former EG4 6000EX. I have read and understand that the EG4 6000XP only handles 4000 watts per PV input. My question is this. In the garage, near the maybe future EG4 6000XP, can I split my singe PV input into two parallel PV inputs, and then run them to PV1 and PV2 on the EG4 6000XP?

 

[sollap]

Yes. The parallel MPPT input on the XP allows for a higher current capability. Just make sure your VOC doesn't exceed the XP's limits.

 

[sunshine_eggo]

Excuse me if this has been asked before. I did a quick search of the forums and did not find anything. My question is this. My previous inverter was a EG4 6000EX with a single PV input. That unit failed last week. ( that's a separate post ). I may be replacing it with a EG4 6000XP. In the past I have seen the EG4 6000EX top out during the summer between 6500 and 7000 watts of PV input ( high noon ). My set up is that I have three strings on the roof all connected to a roof top mounted combiner box that has a single output to the garage where it was connected to the former EG4 6000EX. I have read and understand that the EG4 6000XP only handles 4000 watts per PV input. My question is this. In the garage, near the maybe future EG4 6000XP, can I split my singe PV input into two parallel PV inputs, and then run them to PV1 and PV2 on the EG4 6000XP?

No. You can't put the same array on two MPPT. They will fight over it, and your performance will be horrible.

Concept of how it works (poorly):

MPPT 1 pulls a load
MPPT 2 pulls a load
:LOOP
MPPT 1 sees the power decrease, MPPT 1 reduces the load
MPPT 2 sees more power available, MPPT 2 increases the load
MPPT 1 restarts algorithm and pulls a load
MPPT 2 sees the power decrease, MPPT 2 reduces the load
MPPT 1 sees more power available, MPPT 1 increases the load
MPPT 2 restarts algorithm and pulls a load
Goto LOOP

 

[sollap]

The 6000XP has a parallel MPPT mode - they work together, not against each other.

 

[johnbrutovsky@hotmail.]

No. You can't put the same array on two MPPT. They will fight over it, and your performance will be horrible.

Concept of how it works (poorly):

MPPT 1 pulls a load
MPPT 2 pulls a load
:LOOP
MPPT 1 sees the power decrease, MPPT 1 reduces the load
MPPT 2 sees more power available, MPPT 2 increases the load
MPPT 1 restarts algorithm and pulls a load
MPPT 2 sees the power decrease, MPPT 2 reduces the load
MPPT 1 sees more power available, MPPT 1 increases the load
MPPT 2 restarts algorithm and pulls a load
Goto LOOP

No. You can't put the same array on two MPPT. They will fight over it, and your performance will be horrible.

Concept of how it works (poorly):

MPPT 1 pulls a load
MPPT 2 pulls a load
:LOOP
MPPT 1 sees the power decrease, MPPT 1 reduces the load
MPPT 2 sees more power available, MPPT 2 increases the load
MPPT 1 restarts algorithm and pulls a load
MPPT 2 sees the power decrease, MPPT 2 reduces the load
MPPT 1 sees more power available, MPPT 1 increases the load
MPPT 2 restarts algorithm and pulls a load
Goto LOOP

Question to your response, I see on page 25 of the owner's manual that under PV input mode there is a setting "3: Two MPPT connects to same string. Wouldn't that make my idea work, or no?

 

[sunshine_eggo]

Question to your response, I see on page 25 of the owner's manual that under PV input mode there is a setting "3: Two MPPT connects to same string. Wouldn't that make my idea work, or no?

I wasn't aware of that setting. If it works, it appears you can. It may instruct the MPPT to work together rather than independently.

Now the question becomes are the current limits additive as well, i.e., the two together can use 17A+17A = 34A Imp with a 25A+25A = 50A Isc limit.