PV enphase microinverter

[hhsting]

Does IQ7-60-2-US micro inverter 240V single phase require neutral brought to them? Anyone have manufacturer datasheet or instruction that says neutral is not required?

 

[Carultch]

The trunk cable (Q-cable) that is sold with the Enphase system doesn't even have a neutral in it. If you brought the neutral to either the Q-aggregator or transition box where you transition from Q-Cable to building wire, you would have nowhere to connect it. The neutral is not needed on most applications where it would be applied in the US market. In the international market, they have phase-to-neutral connections of similar 220-240V inverters, where the neutral is active as a current-carrying-conductor, rather than connecting phase-to-phase as we do with 208V and 240V grids.

https://enphase.com/sites/default/files/downloads/support/Q-Cable-Accessories-DS-EN-US.pdf

 

[jaggedben]

There is no general requirement for a neutral in any circuit beyond the service equipment. You do not need any documentation to tell you it's not needed. Unless there's documentation that says that it is needed, then it's not needed.

 

[GoldDigger]

Some earlier 120-0-120 inverters for the US market included a phase-to-phase voltage balance in their conditions for qualifying the grid connection. They definitely required either a wired neutral or a synthesized neutral derived from a (low power) transformer.
The manufacturers specifications for such models included the neutral requirement.

Sent from my Pixel 4a using Tapatalk

 

[ramsy]

Enphase Micro inverters have a control system IQ Envoy that "must be connected to two lines and a neutral for power and for production and consumption monitoring."

Where do the 60A cables fit in that Q aggregator.

https://www.solarelectricsupply.com/fileuploader/download/download/?d=0&file=custom%2Fupload%2FTechBrief-Planning-for-IQ-System.pdf

 

[Carultch]

Enphase Micro inverters have a control system IQ Envoy that "must be connected to two lines and a neutral for power and for production and consumption monitoring."

Where do the 60A cables fit in that Q aggregator.

https://www.solarelectricsupply.com/fileuploader/download/download/?d=0&file=custom%2Fupload%2FTechBrief-Planning-for-IQ-System.pdf

See page 8 for the Q-aggregator product image. There are two lever-operated terminals, where you can terminate up to #4 wire, which is your "60A cables" in question, and a lay-in-lug on the interior of the device for the EGC. It wouldn't necessarily be a cable, as you'd most likely use conduit and separately-installed wire to connect the output wires from the Q-aggregator.

The IQ Envoy is part of a separate product from the Q-aggregator. It is part of the IQ Combiner, which is a brand-specific device for parallelling either branch circuits, or Q-aggregator output circuits, and contains the Envoy for monitoring. It can also be separately-installed to a third-party load center or panelboard, if needed. Once you are on the inverter-side of the IQ combiner or third party panelboard with the Envoy device connected, you no longer need to bring the neutral to Enphase products. The Envoy uses the neutral for running its power supply and instrumentation purposes, but no inverter has the ability to produce neutral currents directly.

 

[mjriz]

Does IQ7-60-2-US micro inverter 240V single phase require neutral brought to them? Anyone have manufacturer datasheet or instruction that says neutral is not required?

Ive designed alot of these systems and never show neutral at least on those components but always show it from the monitoring to point of connected equipment and from combiner panel to service. Also this is on page 10 of their install manual for the IQ7 " Grounding Considerations The Enphase Microinverter models listed in this guide do not require grounding electrode conductors (GEC), equipment grounding conductors (EGC), or grounded conductor (neutral). Your Authority Having Jurisdiction (AHJ) may require you to bond the mounting bracket to the racking. If so, use UL2703 hardware or star washers. The microinverter itself has a Class II double-insulated rating, which includes ground fault protection (GFP). To support GFP, use only PV modules equipped with DC cables labeled PV Wire or PV Cable. "

 

[Steve16]

You only need a neutral to the enphase Combiner box. 2 hots per circuit and a ground up to the roof.

The enphase iq cable only has 2 conductors in it and uses the rails/panel frames as a ground. Not the best grounding methods but what can you do?

 

[Carultch]

The enphase iq cable only has 2 conductors in it and uses the rails/panel frames as a ground. Not the best grounding methods but what can you do?

In terms of construction mechanics, it's a great grounding method. It's makes it a lot easier to install, when your structural fasteners double for electrical continuity.

 

[MikeMakesWhiskey]

You only need a neutral to the enphase Combiner box. 2 hots per circuit and a ground up to the roof.

Ive designed alot of these systems and never show neutral at least on those components but always show it from the monitoring to point of connected equipment and from combiner panel to service. Also this is on page 10 of their install manual for the IQ7 " Grounding Considerations The Enphase Microinverter models listed in this guide do not require grounding electrode conductors (GEC), equipment grounding conductors (EGC), or grounded conductor (neutral). Your Authority Having Jurisdiction (AHJ) may require you to bond the mounting bracket to the racking. If so, use UL2703 hardware or star washers. The microinverter itself has a Class II double-insulated rating, which includes ground fault protection (GFP). To support GFP, use only PV modules equipped with DC cables labeled PV Wire or PV Cable. "

If the Enphase IQ(2-wire) microinverters do not require a GEC or EGC, what is this 'ground up to the roof'?

I have searched for a few days, and the conclusion I have is that the metal on the mounts an panels composing the array is just allowed to be 'free floating' as far as electrical potential since it is double insulated.

To confuse it more, IronRidge refers to the old 4-wire 'engage' cable in their current Flush Mount Installation manual when they exempt the enphase micros from grounding. " Grounding Lugs and wire are not required in systems using certain Enphase microinverters or certain Sunpower modules. Equipment grounding is achieved with the Engage cable for Enphase or the AC module cable system for Sunpower via their integrated EGC. "

I assume it is still *permissable* to run a solid #6 wire from the ground rod near the service to the array, but will it actually help, or will it make a lightning rod. If you were to run this wire still, would best practice be keep it all exterior and go over gutter and under soffit, or run it in/alongside the conduit that enters the attic and exits the soffit?

 

[jaggedben]

If the Enphase IQ(2-wire) microinverters do not require a GEC or EGC, what is this 'ground up to the roof'?

I have searched for a few days, and the conclusion I have is that the metal on the mounts an panels composing the array is just allowed to be 'free floating' as far as electrical potential since it is double insulated.

To confuse it more, IronRidge refers to the old 4-wire 'engage' cable in their current Flush Mount Installation manual when they exempt the enphase micros from grounding. " Grounding Lugs and wire are not required in systems using certain Enphase microinverters or certain Sunpower modules. Equipment grounding is achieved with the Engage cable for Enphase or the AC module cable system for Sunpower via their integrated EGC. "

I assume it is still *permissable* to run a solid #6 wire from the ground rod near the service to the array, but will it actually help, or will it make a lightning rod. If you were to run this wire still, would best practice be keep it all exterior and go over gutter and under soffit, or run it in/alongside the conduit that enters the attic and exits the soffit?

Metal racking requires bonding one way or another. So does any metallic conduit. So there's always going to be a 'ground up to the roof' (EGC), practically speaking. Nothing is allowed to be 'free floating' if that means unbonded.

What the Ironridge manual is referring to is that in some cases you could use the ground provided in an Enphase or similar cable to bond the racking. In this case the inverters metal mounting bracket should have been bonded to the racking using a WEEB or such. These systems are mostly out of production, meaning these days you have to bond the racking using your own provided EGC on the rack.

Ten years ago Enphase inverters also required a GEC (which could be the same wire), but that is very out of date at this point.

Your array EGC should go (ultimately) to the service neutral like all EGCs. Notwithstanding the wrong-headed and subsequently removed 690.47(D) in the 2014 code, running a GEC directly from an array to a ground rod is pointless and possibly dangerous. But I suppose you're correct that it's still permissable.

 

[Carultch]

In this case the inverters metal mounting bracket should have been bonded to the racking using a WEEB or such. These systems are mostly out of production, meaning these days you have to bond the racking using your own provided EGC on the rack.

It is still common that equipment can be directly bonded to the racking without a jumper, just not necessarily with WEEBs. In Ironridge's case, they have a T-bolt and flange nut that accomplishes both mechanical and electrical continuity. Some equipment allows you to use a star washer for electrical continuity, so that you can use it in combination with standard fasteners for mechanical continuity.

 

[MikeMakesWhiskey]

Metal racking requires bonding one way or another. So does any metallic conduit. So there's always going to be a 'ground up to the roof' (EGC), practically speaking. Nothing is allowed to be 'free floating' if that means unbonded.

What the Ironridge manual is referring to is that in some cases you could use the ground provided in an Enphase or similar cable to bond the racking. In this case the inverters metal mounting bracket should have been bonded to the racking using a WEEB or such. These systems are mostly out of production, meaning these days you have to bond the racking using your own provided EGC on the rack.

Ten years ago Enphase inverters also required a GEC (which could be the same wire), but that is very out of date at this point.

Your array EGC should go (ultimately) to the service neutral like all EGCs. Notwithstanding the wrong-headed and subsequently removed 690.47(D) in the 2014 code, running a GEC directly from an array to a ground rod is pointless and possibly dangerous. But I suppose you're correct that it's still permissable.

I appreciate you taking the time to answer. I thought it was how a double insulated appliance could get away without a EGC and be 2-conductor... the wording from enphase really makes it seem that way...
" Grounding Considerations The Enphase Microinverter models listed in this guide do not require grounding electrode conductors (GEC), equipment grounding conductors (EGC), or grounded conductor (neutral). "

So, following your explanation, and you install the EGC, would it be a 'good practice' to go solid #6 from the racking to the j-box above the roof penetration, convert to a #10 green THHN where you are protected, and continue to the AC combiner (lower left of the enphase combiner 3 pictured) that has a ground bus that is in turn connected to the main load center ground bus?

 

[jaggedben]

So, following your explanation, and you install the EGC, would it be a 'good practice' to go solid #6 from the racking to the j-box above the roof penetration, convert to a #10 green THHN where you are protected, and continue to the AC combiner (lower left of the enphase combiner 3 pictured) that has a ground bus that is in turn connected to the main load center ground bus?

What you describe is essentially required, although you have some leeway with wire sizes and such. I'm not of the opinion that #6 is really needed on the array, for example, although that is actually required by code (but rarely enforced in my area). On the other hand, code would allow you to use EMT as your EGC and just jumper to bonding bushings at each end. But a wire EGC is good practice and I've never not done it.

 

[MikeMakesWhiskey]

What you describe is essentially required, although you have some leeway with wire sizes and such. I'm not of the opinion that #6 is really needed on the array, for example, although that is actually required by code (but rarely enforced in my area). On the other hand, code would allow you to use EMT as your EGC and just jumper to bonding bushings at each end. But a wire EGC is good practice and I've never not done it.

Thank again!