I hope I did not screw this up Phocos PSW-H-5KW-120/48V

[Jmac786]

I'm also considering the Phocos PSW-H 5kw/120v for my off-grid build. The 250V current limit on the dual MPPTs was one of the attractive points for me, keeping panel set-up simple (two 5s strings).

One of my main questions is around generator compatibility. I've got a Honda EU2200i that I'd like to use for charging the batteries as necessary. Some of the product literature/videos give me the impression that operation is somewhat binary (ie, either in "Off-Grid" mode or "On-Grid" mode), which would mean that while charging with the EU2200i, the inverter/panels would not be functioning. I'm hoping that I have that wrong, as would want to maintain the full 5kw capacity of the inverter, even when I'm charging with the genset.

I've contacted Phocos several times in the past week with no response (not a great sign in itself...). Anyone have thoughts on my situation?

Jon

Yes, you can use your AC source (generator) while having your PV array as your primary energy source. I believe they answer this in video #2 of this series. Customer service does feel like a China chop shop right now though. For the record, I won’t be using a generator with mine since we have stable grid power. I will have a battery bank though.

 

[Tanter]

I'm also considering the Phocos PSW-H 5kw/120v for my off-grid build. The 250V current limit on the dual MPPTs was one of the attractive points for me, keeping panel set-up simple (two 5s strings).

One of my main questions is around generator compatibility. I've got a Honda EU2200i that I'd like to use for charging the batteries as necessary. Some of the product literature/videos give me the impression that operation is somewhat binary (ie, either in "Off-Grid" mode or "On-Grid" mode), which would mean that while charging with the EU2200i, the inverter/panels would not be functioning. I'm hoping that I have that wrong, as would want to maintain the full 5kw capacity of the inverter, even when I'm charging with the genset.

I've contacted Phocos several times in the past week with no response (not a great sign in itself...). Anyone have thoughts on my situation?

Jon

It has several modes of operation pv priority, grid priority etc. If i understand your question right you would use the no priority setting run the generator on the grid input, solar on the pv input and both would be charging the batteries while the inverter powers your load.

 

[Tanter]

we have stable grid power.

Wish I did. Power is out now starting up the generator to keep our food cold.

 

[Jmac786]

Wish I did. Power is out now starting up the generator to keep our food cold.

Funny thing... high winds knocked it out for about 2 hours after I posted that today. The wife was quick to respond that if I wasn’t so cheap we’d already have solar.

 

[Tanter]

Funny thing... high winds knocked it out for about 2 hours after I posted that today. The wife was quick to respond that if I wasn’t so cheap we’d already have solar.

North Ohio? Ours is still out with no estimate when it might be back. Told my wife we may have to go bigger. She was not into it... yet...

 

[Jmac786]

North Ohio? Ours is still out with no estimate when it might be back. Told my wife we may have to go bigger. She was not into it... yet...

Southern Ohio. I’m all the way at the bottom in Ironton. Most of the day was beautiful just windy. The outage was only for 12 houses here.

 

[schroederjd]

I just received the following response from Phocos regarding my 'undersized' generator. Based on this response, it looks like the inverter won't be able to pull current from the batteries when the Genset is running. If that's true, when there's no PV current coming from the panels, if I have the Genset running (to charge batteries), my AC loads would be limited to the capacity of the generator. Does that seem odd to anyone else?

My questions are in Blue, Phocos responses are in Red.

1. Is my Honda EU2200i compatible as an AC Input source with the PSW-H/5kw/120v inverter/charger?
2. In cases where my PV panels are not able to keep up with my energy use, I’d like to be able to use my EU2200i for charging the batteries while maintaining the full capacity of my 5kw inverter. Can you confirm that this is possible?
3. Does the PSW-H allow a generator to ‘assist’ the inverter with high loads? That is, will the system’s total AC output capacity be increased by running the generator?

"We don’t recommend such low gensets if your loads are 5KW or more. That’s the reason we specify 7.5KW in the webinar (1.5 times the rating of the inverter). The PSW cannot limit the AC input current delivered to the loads (there’s just a relay in between). A combination of solar and genset to power the loads is possible, but if the panels are not able to keep up with your energy use (cloud, night time) then the genset might be too small for your loads so you will not be getting the full capacity of the inverter 5KW (only the ~2kW of the genset will be used).

The overload bypass of the inverter (when enabled) can switch on the AC input to assist (say 5kW from solar and the excess required from the load can come from the AC input) but we have never tested this for gensets of this size (1.8kW I believe the EU2200i is)."

 

[Hedges]

Can't tell from the datasheet if it functions as grid-tie (backfeeding) or not.
A bit odd, but not unexpected. Easier to deliver 100% of PV to AC and get extra from grid than to regulate it.

Other inverters such as my Sunny Island can be programmed for maximum current from grid/generator and will produce additional power from battery as needed. Also programmed for backfeed or not (in case of generator, never backfeed.)

Software. It is the most difficult part.

Maybe get a separate battery charger and have generator power that.

 

[schroederjd]

I've got a Victron MultiPlus-based setup that I'm basing my experiences/expectations around. That system is extremely flexible when it comes to where power is coming from and how it's used. I probably need to re-calibrate my expectations if I'm going to move to an 'all-in-one' type system. And honestly, as long as I can charge the batteries with the genset on the rare occation that my PV isn't keeping the batteries charged, I can manage my AC loads during that period to make sure I'm not exceeding the generator's capacity.

Separate charger is not a bad idea though. Gives me a bit more redundancy as well.

 

[Jmac786]

I just received the following response from Phocos regarding my 'undersized' generator. Based on this response, it looks like the inverter won't be able to pull current from the batteries when the Genset is running. If that's true, when there's no PV current coming from the panels, if I have the Genset running (to charge batteries), my AC loads would be limited to the capacity of the generator. Does that seem odd to anyone else?

My questions are in Blue, Phocos responses are in Red.

1. Is my Honda EU2200i compatible as an AC Input source with the PSW-H/5kw/120v inverter/charger?
2. In cases where my PV panels are not able to keep up with my energy use, I’d like to be able to use my EU2200i for charging the batteries while maintaining the full capacity of my 5kw inverter. Can you confirm that this is possible?
3. Does the PSW-H allow a generator to ‘assist’ the inverter with high loads? That is, will the system’s total AC output capacity be increased by running the generator?

"We don’t recommend such low gensets if your loads are 5KW or more. That’s the reason we specify 7.5KW in the webinar (1.5 times the rating of the inverter). The PSW cannot limit the AC input current delivered to the loads (there’s just a relay in between). A combination of solar and genset to power the loads is possible, but if the panels are not able to keep up with your energy use (cloud, night time) then the genset might be too small for your loads so you will not be getting the full capacity of the inverter 5KW (only the ~2kW of the genset will be used).

The overload bypass of the inverter (when enabled) can switch on the AC input to assist (say 5kW from solar and the excess required from the load can come from the AC input) but we have never tested this for gensets of this size (1.8kW I believe the EU2200i is)."

Sounds like a “Yes, but..” answer. As in yes you can, but you’re not going to have the capacity for a 5 ton heat pump. You’ll be limited in what you can do in this situation, which is what tech support is trying to help you avoid. You’ll need to program the Phocos for SBU mode.
First: Solar
Second: Battery
Third: Utility (generator)

The problem I see here is the inefficiency of using the generator to backfill a battery that is simultaneously going to be feeding your loads. In the event of an outage, you might want to switch to SUB (solar-generator-battery). SBU would be your standard cost saving mode, whereas SUB would be activated after grid power loss. That seems wordy.. Does that make sense?

Edited Abbreviations (SUB/SBU)

 

[schroederjd]

Sounds like a “Yes, but..” answer. As in yes you can, but you’re not going to have the capacity for a 5 ton heat pump. You’ll be limited in what you can do in this situation, which is what tech support is trying to help you avoid. You’ll need to program the Phocos for SBU mode.
First: Solar
Second: Battery
Third: Utility (generator)

The problem I see here is the inefficiency of using the generator to backfill a battery that is simultaneously going to be feeding your loads. In the event of an outage, you might want to switch to SUB (solar-generator-battery). SBU would be your standard cost saving mode, whereas SUB would be activated after grid power loss. That seems wordy.. Does that make sense?

Edited Abbreviations (SUB/SB Jmac.

That makes perfect sense Jmac. Thanks.

Seems like the functionality of the Phocos PSW-H is pretty standard for an 'all-in-one' design. In the rare event that my PV hasn't been able to keep up with my charging needs (eg, periods of heavy snow), I'll be able to use the genset to charge the batteries using the SUB priority setting, but I'll need to manage my loads carefully during that period. Shouldn't be a problem.

Note that this is mainly a consideration for me because this system is going into an off-grid cabin that won't see much use in the winter. There will be some smaller loads on all the time (eg, pumps for in-floor heat, Wifi, etc.) that could draw down the batteries in the event that the panels get covered with snow. I just want to make sure i have some backup method for charging the batteries.

 

[Jmac786]

Seems like the functionality of the Phocos PSW-H is pretty standard for an 'all-in-one' design.

Someone else referred to it as a rebranded MPPT for $400 more. That’s a fair assessment. The biggest differences that I can see are:

1. Pin coded grid backfeed (MPPT can’t backfeed at all)
2. Ability to pass inspection
3. Expandable to 45KW (MPPT capped at 15kw)
4. Weighs 40 pounds (MPPT 72lbs)

Those features are definitely worth $400 in a true hybrid application. However, with off-grid you’ll never need the first three.

 

[schroederjd]

Someone else referred to it as a rebranded MPPT for $400 more. That’s a fair assessment. The biggest differences that I can see are:

1. Pin coded grid backfeed (MPPT can’t backfeed at all)
2. Ability to pass inspection
3. Expandable to 45KW (MPPT capped at 15kw)
4. Weighs 40 pounds (MPPT 72lbs)

Those features are definitely worth $400 in a true hybrid application. However, with off-grid you’ll never need the first three.

In terms of functionality, I agree. Not a lot of distance between those two devices. The biggest (ie, most relevant) differences for me are:

1. Max PV string voltage (250v for Phocos, 150v for MPP) - simplifies the wiring a bit
2. Idle consumption (14W for Phocos, 24w for MPP) - my system is likely to be sitting idle a lot in winter, when snow could be covering the panels
3. Inverter Efficiency, from PV (>96% for Phocos, >90% for MPP) - not sure why I care about this...but I do...

In the grand scheme, none of those factors are likely to be truely impactful, but I do get the sense that the Phocos unit is a bit higher on the quality scale. I suppose that's what's driving me away from MPP, more than anything.

 

[Tanter]

1. Max PV string voltage (250v for Phocos, 150v for MPP) - simplifies the wiring a bit
2. Idle consumption (14W for Phocos, 24w for MPP)

The 250v MPPT was the deciding factor for me but almost half the idle consumption sounds good too.

 

[Tanter]

North Ohio? Ours is still out with no estimate when it might be back. Told my wife we may have to go bigger. She was not into it... yet...

Finally got power back on last night. Sure wish I had the solar up and running. Dealing with a generator sucks but I guess I am glad I had it for now.

 

[Tanter]

just got my batteries ordered 16 cells 48v 280ah for $1600. I hope they show up and are new like promised. This sure is getting expensive but will be worth it when the power goes out.

 

[ArthurEld]

By the way, ever learn to use a slide rule?

I did. You must be old.
How about vernier calipers?

 

[Hedges]

I did. You must be old.
How about vernier calipers?

My mom just turned 100.
She was playing tennis at 98.
She was a school teacher when I was growing up and had a slide rule, probably left over from her college days. I learned to use it as a curiosity.
The electronic calculator was created after I was born. My mom got a "Bomar Brain", 4-function calculator which cost several hundred dollars (a week's pay).
I still use the HP 41-CV I bought with my employee discount.

Yea, but more often vernier micrometer. That reads to 0.0001"

I suppose if I was up to date I'd be using a laser interferometer.
Past employers used VISAR

Velocity interferometer system for any reflector - Wikipedia

en.wikipedia.org

 

[sunshine]

if I have the Genset running (to charge batteries), my AC loads would be limited to the capacity of the generator. Does that seem odd to anyone else?

In pt3 of the videos this is discussed #3 webinair from 18 minute mark.

Maybe someone more technically minded can view that section and confirm the reasons as per the reply you received from them-
"
"We don’t recommend such low gensets if your loads are 5KW or more. That’s the reason we specify 7.5KW in the webinar (1.5 times the rating of the inverter). The PSW cannot limit the AC input current delivered to the loads (there’s just a relay in between). A combination of solar and genset to power the loads is possible, but if the panels are not able to keep up with your energy use (cloud, night time) then the genset might be too small for your loads so you will not be getting the full capacity of the inverter 5KW (only the ~2kW of the genset will be used).

The overload bypass of the inverter (when enabled) can switch on the AC input to assist (say 5kW from solar and the excess required from the load can come from the AC input) but we have never tested this for gensets of this size (1.8kW I believe the EU2200i is).""

 

[JoeHam]

Found my slide rule today, pics attached.

Did anyone ever get a Phocos?