Single- Phase Inverter for Commercial project

[inforaj]

One of the customers has two separate meters and will be required a 165 KW DC system for their warehouse. The available voltage on-site is 120/240 volts.

One of the distributors said FRONIUS FRIMO 15 KW, but many of the inverters will be required, and that will increase the project cost.

Could you please advise any other option or high-capacity inverter brands that will decrease the project cost?

I really appreciate any help you can provide.

 

[ggunn]

One of the customers has two separate meters and will be required a 165 KW DC system for their warehouse. The available voltage on-site is 120/240 volts.

One of the distributors said FRONIUS FRIMO 15 KW, but many of the inverters will be required, and that will increase the project cost.

Could you please advise any other option or high-capacity inverter brands that will decrease the project cost?

I really appreciate any help you can provide.

Unfortunately, for a 165kW PV system on a 240/120V service you are kinda screwed for inverters. All the high power PV inverters I know of are three phase, so even with transformers you cannot interconnect them with single phase services.

 

[pv_n00b]

I'm curious about the service rating. The PV system will put out almost 700A at 240V and a 700A 240/120V service is unusually large. The interconnection is going to use a 1,000A OCPD. That's going to be a difficult system at that voltage single phase.

 

[ggunn]

One of the customers has two separate meters and will be required a 165 KW DC system for their warehouse. The available voltage on-site is 120/240 volts.

One of the distributors said FRONIUS FRIMO 15 KW, but many of the inverters will be required, and that will increase the project cost.

Could you please advise any other option or high-capacity inverter brands that will decrease the project cost?

I really appreciate any help you can provide.

What size is the service? 125% of the maximum inverter current cannot exceed the ampacity of the service conductors.

 

[wwhitney]

What size is the service? 125% of the maximum inverter current cannot exceed the ampacity of the service conductors.

Unless you have a service OCPD that is 100% rated. And actually that's for service entrance conductors, other service conductors never need the 125% factor.

Cheers, Wayne

 

[inforaj]

I'm curious about the service rating. The PV system will put out almost 700A at 240V and a 700A 240/120V service is unusually large. The interconnection is going to use a 1,000A OCPD. That's going to be a difficult system at that voltage single phase.

The customer has two separate meters with two accounts. We are planning to divide the system into two units.
165 KV DC that will go down, but 400 A OCPD for each unit will be okay for this system. --- that's the plan. What do you say about this plan?

 

[inforaj]

What size is the service? 125% of the maximum inverter current cannot exceed the ampacity of the service conductors.

Available utility service is 1000 Amp busbar, 120/240 volts

 

[ggunn]

Unless you have a service OCPD that is 100% rated. And actually that's for service entrance conductors, other service conductors never need the 125% factor.

Well, OK, but it still doesn't make sense to me. Another thing, though, the OP needs to make sure that the total PV kW does not exceed the kVA rating of the transformer that is likely powering both services. Some POCOs have a further restrictive percentage of the kVA allowed, too.

Back when we first started doing commercial PV that one got us; there were two car dealerships on adjacent properties that we sold PV systems to; our systems were smaller than their respective services, but both services were on the same transformer and the total kW of the two PV systems exceeded its kVA rating. That was an expensive lesson for us; we had to eat the cost of a new larger transformer.

 

[inforaj]

Well, OK, but it still doesn't make sense to me. Another thing, though, the OP needs to make sure that the total PV kW does not exceed the kVA rating of the transformer that is likely powering both services. Some POCOs have a further restrictive percentage of the kVA allowed, too.

Back when we first started doing commercial PV that one got us; there were two car dealerships on adjacent properties that we sold PV systems to; our systems were smaller than their respective services, but both services were on the same transformer and the total kW of the two PV systems exceeded its kVA rating. That was an expensive lesson for us; we had to eat the cost of a new larger transformer.

That is an excellent point that needs to verify with the utility. Thanks, ggunn.

 

[pv_n00b]

That is an excellent point that needs to verify with the utility. Thanks, ggunn.

Never assume the service rating is based on the customer service equipment rating. I have seen time and time again that the POCO has provisioned a service that is sometimes much less than the customer service entrance equipment rating. I had one project where this happened and the POCO wanted to charge for installing a larger utility transformer and add a monthly fee to the customer's bill to charge for the excess size of the transformer over what they considered was needed for the service. We reduced the size of that PV system slightly.

 

[pv_n00b]

The customer has two separate meters with two accounts. We are planning to divide the system into two units.
165 KV DC that will go down, but 400 A OCPD for each unit will be okay for this system. --- that's the plan. What do you say about this plan?

You need at least a 430A CB to interconnect each 82.5kW system. Upsizing that to a common size means a 450A CB. You say the service equipment has a 1,000A bus so that means that you have a single service with two meters. That is not two services. On single-phase services, FERC has set a limit on how much the back feed from a PV system can be on a shared utility transformer. That will be a problem here if the transformer is shared between customers.
It looks like you are at the upper limit on this possible utility service. Make sure you get your utility approval before you turn a wrench. It would be a shame to get two systems installed only to have the utility tell you that you can't get PTO. I've seen systems installed without utility approval only to have the utility say they can't be turned on, no one is happy, and the installer loses a lot of money.