Outback inverter actual ratings [RE-wrenches]

[Todd Cory, Mt. Shasta Energy Services]

You might just be able to get away with 3500 STC watts of PV because the 
inverter will likely only be selling around 2400 watts (67% of rated 
power). Pushing it much beyond that (like I am doing) and you basically 
end up with LOTS of additional heat.

Watch the "air (transformer) temp" reading. If it gets to around "45" 
you are close to shutting down, and really even running it at "70" I 
feel is to hot for the components to last very long. Contact me off list 
for the conversion of temp counts in the mate to actual degrees C & F.

What I do not understand is that if it is called a 3600 watt inverter 
(and the specifications say 3600 watts continuous) why does it max out 
selling around 2800 watts before overheating at 25 degrees C?

The limitation is with the GVFX not the MX60. Mine is trying to sell 
2900 watts and IMO gets really too hot to last very long. Yes, I am 
pushing this stuff hard, but only to 80% of its rating. This is well 
below what the manufacturer says:

Vented Models
VFX3648
48 VDC
Continuous Power Rating at 25 ° C 3600 VA/

How are we to design our systems if we cannot trust the manufacturer 
specifications? If I was stating the specifications I would call it a 
2800 watt inverter (GVFX2848). Is it typical for inverters to be 
overrated like this?

Todd 



Allan Sindelar wrote:
> 
> Todd,
> Now I'm suddenly concerned: We have several Outback PS1 systems in
> operation, including one with 3,500 W of PV on the roof. This was 
> checked
> out with Outback tech support, as the MX-60 is rated to max 3,200 W of 
> PV.
> We haven't been through summer yet with this one: are we in for serious
> inverter overheating with this system?
> 
> I could sure use some reassurance from C. Freitas about now, after 
> reading
> your post.
> Allan at PosE
> 
>  ----- Original Message ----- 
> From: "Todd Cory, Mt. Shasta Energy Services" 
> <toddcory at finestplanet.com>
> 
> I just discovered the GVFX3648's continuous at 25º C wattage rating is a
> bit... ahhh shall we say "embellished". I recently added more PV to my
> home system and now am selling ~2900 watts to the grid. The unit running
> with 70º F ambient air was (according to the mate AIR temp readout)
> running at 238º F (114º C). According to Outback, the unit was just
> about to shutdown from over temperature it was so hot. This is at only
> about 80% of the stated load capability!
> 
> So I removed the "valve cover", and about half of the bottom plastic
> "bug screens" installed in the air exhaust ports. Today the unit was
> operating in 88º F ambient temps but was running at 208º F, so assisting
> the air flow dropped the internal air temp 30º F with the ambient temp
> 18º F hotter. This means that improving the air flow greatly improved
> the inverters ability to sell at 80% of rated "continuous" loading.
> 
> Still running the unit at 208º F does not bode well for the longevity of
> the electronics. The next "hack" is to add an air inlet booster fan. If
> the internal fan is getting air from an upstream fan the air volume will
> be turbocharged. Yes, the ultimate solution is a second inverter, but
> why do they sell something that will only make 80% of rated power? I
> know this standard practice from the PV manufactures, but I did not know
> the inverter manufactures were also doing this. Has anyone else
> experienced the rating of other inverters to be a bit more than they
> will actually do?
> 
> Todd
> 


- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read

List rules & how to change your email address: www.mrsharkey.com/wrenches/etiquette.php

Check out participant bios: www.mrsharkey.com/wrenches/

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------