The "air temp" IS the transformer temperature.
Shutdown for the transformer is @ 38 counts (250.7 degrees F)
Shutdown for cap/fet boards is @ 79 counts (194.2 degrees F)
(see attached chart for temp counts to degree F/C conversion)
Selling 2.7 kW (75% loaded) on a hot summer day (ambient of 92F in the power building) before modifications I typically saw:
Trans = 43
Fet = 143
Cap = 147
Selling only 2.7 kW (75% loaded) on a hot summer day (ambient of 92F in the power building) after modifications I typically see:
Trans = 50 (still way too hot to touch the case above the xmfr)
Fet= 155
Cap = 169
Modifications included:
- Removing the "bug screens" above and below the fet/cap boards
- Adding another fan on top of the internal fan's air intake.
My typical efficiency (PV input wattage versus actual selling wattage) runs ~87%.
Hope this is helpful.
Todd
On Friday, February 26, 2010 9:59am, "Michael Welch" <[email protected]> said:
>
> >From: [email protected]
> >
> >toddcory at finestplanet.com writes:
> >> How high have the temp counts on your transformer gotten?
> >
> >I'd pay closer attention to the FET and CAP temperatures. The
> >transformer sensor measures air temperature
> >and the other two get hotter, faster.
> >
> >> > I have a test coming up for a client where I'm going to try and get
> a
> >> > pair of GVFX3648's to sell 7.2KW.
> >>
> >> My home system's GVFX3648 maxes out at around 2.8 to 2.9 kW @ 80 degrees
> F. If I push it harder, it
> >> overheats. While they are rated at "3600 watts", they cannot do this
> continuously with ambient temps
> >> above ~40 F.
> >
> >I'll be monitoring the FET, CAP and AIR temperatures while they are
> >selling. If the temperatures get
> >out of hand, the software will back off the amount of sell power.
> >--
> >Julie Haugh
> >Senior Design Engineer
> >greenHouse Computers, LLC // jfh at greenhousepc.com // greenHousePC on
> >Skype
>
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Air Temp, Cap Temp Values.pdf
Description: Adobe PDF document
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