Fronius Symo 480V

[gporter85]

I installed 3 Fronius Symo 480V inverters specifically, because they list the grid type as 480V Delta + N. I connected them to a 480 delta system. Along with a neutral and ground coming from the service disconnect. A and B phase read 240 phase to neutral and C phase reads 415 ground to neutral. Fronius is telling me the inverter wont turn on, because it sees the high leg out of voltage range. I am confused, because when i think of a delta system it generally has a high leg. Anyone every installed a Fronius Symo before? I know they are relatively new. On the phone a tech told me the legs should all read 277 which is a Wye configuration. Their grid specialist was supposed to call me back Friday afternoon and didn't.

http://www.fronius.com/cps/rde/xchg...ronius_usa/hs.xsl/2714_11153.htm#.Vq59HoU4GUk

I saw nothing about no high leg delta systems.

 

[electrofelon]

I installed 3 Fronius Symo 480V inverters specifically, because they list the grid type as 480V Delta + N. I connected them to a 480 delta system. Along with a neutral and ground coming from the service disconnect. A and B phase read 240 phase to neutral and C phase reads 415 ground to neutral. Fronius is telling me the inverter wont turn on, because it sees the high leg out of voltage range. I am confused, because when i think of a delta system it generally has a high leg. Anyone every installed a Fronius Symo before? I know they are relatively new. On the phone a tech told me the legs should all read 277 which is a Wye configuration. Their grid specialist was supposed to call me back Friday afternoon and didn't.

http://www.fronius.com/cps/rde/xchg...ronius_usa/hs.xsl/2714_11153.htm#.Vq59HoU4GUk

I saw nothing about no high leg delta systems.

Hmmm, I am not familiar with that inverter. I agree with you, "480V delta + N" to me implies a 480V high leg system. That is an odd system, I cant imagine them designing an inverter around such an oddball system. I suspect they are using bad/different terminology - perhaps by "delta" they mean a wye but are trying to say the inverter neutral doesn't carry current?? Thats the best Ive got, maybe someone else will chime in.

 

[GoldDigger]

I agree. They should only be saying that the inverter does not generate line to neutral current, not that the source can be wired as delta.
With the possible exception of high leg delta, there is no such thing as a delta with a neutral.

 

[Smart $]

I agree. They should only be saying that the inverter does not generate line to neutral current, not that the source can be wired as delta.
With the possible exception of high leg delta, there is no such thing as a delta with a neutral.

None which are considered common in the US.

A rare system is a 480V delta high leg with a "true" neutral created via a zig zag transformer.

 

[electrofelon]

I looked at the fronius site and they use that "delta + N" jargon for all of their commercial inverters. Maybe that is common jargon in Austria, but they should really correct that...

 

[jaggedben]

I installed 3 Fronius Symo 480V inverters specifically, because they list the grid type as 480V Delta + N. I connected them to a 480 delta system. Along with a neutral and ground coming from the service disconnect. A and B phase read 240 phase to neutral and C phase reads 415 ground to neutral. Fronius is telling me the inverter wont turn on, because it sees the high leg out of voltage range. I am confused, because when i think of a delta system it generally has a high leg. Anyone every installed a Fronius Symo before? I know they are relatively new. On the phone a tech told me the legs should all read 277 which is a Wye configuration. Their grid specialist was supposed to call me back Friday afternoon and didn't.

http://www.fronius.com/cps/rde/xchg...ronius_usa/hs.xsl/2714_11153.htm#.Vq59HoU4GUk

I saw nothing about no high leg delta systems.

I have no familiarity with that specific inverter, but my understanding with previous Fronuis inverters is they can be programmed to ignore the neutral. You probably need a higher level tech to help you, so keep trying. If it's possible that is. It may not be possible with this inverter.

Very few inverters can handle a high-leg delta so it's always a good idea to double-check with the manufacturer before installing. And BTW, there are deltas with and without high-legs.

 

[BillK-AZ]

The Fronius Installation manual does not show the 480V Delta with N as an acceptable grid:

 

[ggunn]

Strange that they would allow 208V and 240V 3P with no neutral but not 480V 3P without neutral.

 

[electrofelon]

Strange that they would allow 208V and 240V 3P with no neutral but not 480V 3P without neutral.

I was thinking the same thing. Ive always been unclear on why inverter manufactures seem to have a strong preference for having a neutral. I would love to not have to pull a neutral to 13 inverters - and it always seem to be a full sized too....

 

[GoldDigger]

Strange that they would allow 208V and 240V 3P with no neutral but not 480V 3P without neutral.

Also note that they specifically support 120/240 three phase high leg, but not 240/480 high leg. So they probably do not really consider that "with neutral".

 

[gporter85]

I have no familiarity with that specific inverter, but my understanding with previous Fronuis inverters is they can be programmed to ignore the neutral. You probably need a higher level tech to help you, so keep trying. If it's possible that is. It may not be possible with this inverter.

Very few inverters can handle a high-leg delta so it's always a good idea to double-check with the manufacturer before installing. And BTW, there are deltas with and without high-legs.

I checked with my sales rep at my supplier and he said we needed the Fronius for the 480 delta.

I also called Fronius tech support and asked if phase rotation or the Position of the high leg mattered. And they told me it did not. I also asked about the neutral and they said I needed to run a separate neutral from ground for voltage sensing. I really though nothing strange of it. Residential systems use a separate ground beyond the service disconnect. And a Pump doesn't require a neutral so that is why one is not ran. This a 4 wire system from the POCO.

Then a few months later at the moment of truth I get a couple of error messages.

There grid specialist was supposed to call me back Friday and did not call me back today either. I am pretty sure i know why.

It sound like I will probably need a delta wye transformer. Which really P's me O.

480 delta is a common configuration in my area. I live in the central valley and I would be willing to bet over 50% of the Ag pumps over 50hp are on 480 Delta. Unless you ask fronius then 100% are.

 

[gporter85]

The Fronius Installation manual does not show the 480V Delta with N as an acceptable grid:

Like a dumb*** I did not look at the instructions until after i bought it. The inverter listed 480 delta right on the side of it. I feel like i was swindled.

 

[GoldDigger]

Like a dumb*** I did not look at the instructions until after i bought it. The inverter listed 480 delta right on the side of it. I feel like i was swindled.

It can happen with otherwise reputable companies.

I bought a particular HP printer because it was listed in all of their literature as compatible with Windows NT.
It turned out that the drivers would only work on NT Workstation OS, not NT Server OS. And they had no intention to change that.

 

[ggunn]

I checked with my sales rep at my supplier and he said we needed the Fronius for the 480 delta.

I also called Fronius tech support and asked if phase rotation or the Position of the high leg mattered. And they told me it did not. I also asked about the neutral and they said I needed to run a separate neutral from ground for voltage sensing.

Hmmm. Separate "neutral" from ground? If the 480 service is not referenced to ground or if a center tap between two phases is grounded, that's a problem. I think you'll need a delta to wye transformer with the neutral grounded on the wye side.

 

[GoldDigger]

Hmmm. Separate "neutral" from ground? If the 480 service is not referenced to ground or if a center tap between two phases is grounded, that's a problem. I think you'll need a delta to wye transformer with the neutral grounded on the wye side.

I think that a small zig-zag transformer just to create an ungrounded neutral reference point might work too, but much more information is needed as I do not trust the sequence of partially contradictory information the OP has been given.

 

[gporter85]

I think that a small zig-zag transformer just to create an ungrounded neutral reference point might work too, but much more information is needed as I do not trust the sequence of partially contradictory information the OP has been given.

I called Fronius yesterday and their grid guy that was supposed to call me is out of town this week. The tech i talked to was very adamant that they need a delta with a Neutral, not necessarily a WYE. I asked why the 240 stinger works, but not the 480. It seems to me it would be as simple as changing the acceptable voltage range in the inverter's programming. That is easy for me to say as I am a contractor, not an engineer or a computer programmer.

But the guy was really stressing on the Neutral part which makes me think a zig zag transformer might be an option. What would the voltage phase to neutral show on the ungrounded neutral reference??? If I get a Delta to WYE 480 transformer i would need one 15KVA for each small system and one 30KVA for the large system. But if this N is only used as a reference. Could i use a very small zig zag transformer at each service and just grab the nuetral that is a non current carrying conductor.

This is a 3 phase 4 wire system. There is a Ground/neutral coming from the pole.

Fronius is being very unhelpful in the tech support department. They are barely willing to accept 480 center tapped delta as a grid. And apparently I am the only person to hook this inverter up wrong.