sola basic adjustment pot

Hi Almot,

Yes, but buck has never been an issue in Canada or USA.

1st layer of boost at 110 is 10% to 121 (no load)
2nd layer of boost at 100 is 20% to 121 (no load)
3rd layer of boost at 90 is still only 20% to 109 (no load)

I'm not sure why they bothered with the 3rd layer since it appears to do the same thing as the 2nd layer. It definitely does happen. i.e. the meter reading does rise at 90 volts of input.

I'm tempted to rent a variac and play all day long figuring out boost numbers from an input of 121 right down to 85.

The "load" when testing was a 300 watt incandescent bulb. Pure resistive load.

Thanks for the link, Don.

So, if this single pot is responsible for trigger voltage - and then relays direct it to +20%, +10% or -10% coil, - it means your buck point has also moved 2V up now, to 137V.

I came across a nice video that explains how boost/buck and autoformers work: https://www.youtube.com/watch?v=zKasA4HxaGY

The explanation comes in the first 3 minutes.

MrWizard has that right (as usual). The percentage of boost is not adjustable and is "hardwired" into the autotransformer. There are three "taps" for boost. And one tap for buck.

Almot,

The trigger set points were changed. They are now approximately 112, 102, and 92 volts. I don't have access to a variac or isolation transformer to double check the numbers. They may be higher than what is listed above--but they are certainly not lower.

The boost deferential, which a percentage, remains unchanged.

From the OEM literature 110-->121, or 10%. But that would be with no load.

In real life as load increases the input voltage sags more and more while the boosted voltage is based on that 10%. So, at 106 volts input volts, boost is 10% giving about 117 volts inside the RV.

Again in "real life" with the same load, boosted voltage works out to 117 with the autoformer, and 102 volts without the autoformer.

The real "power" difference is about 1950 watts with booster @ 117 volts, and about 1800 watts without boost at 102 volts.

The above numbers were take while plugged into a 30 amp service with 50 feet of #10 wire (two cords daisy chained).

i think the amount of boost is built in
it is set by the turns in the secondary winding, which is selected by the relay
the pot adjusts the set point where the relay (boost) comes into play

This humble box is looking better and better.

I am a little confused. Did you increase the boost at 100V to 17-23 depending on the load? Or did you change the trigger point from 100 to 102 while leaving the boost at 14-20 as before?

congrats.. you got it adjusted, all setup now

Hi all,

Well, there is exactly ONE pot. It has been tweaked and I'm using it to get full power from my electric heaters.

I'm running 2860 watts @ 117 volts. Without the autoformer that would have dropped to about 102 volts. I'm plugged into a 30 amp circuit at my brother's cottage which has chronically low voltage. It is just too far from the transformer.

The pot is a tiny blue one next to an led. It can be adjusted without any trouble at all.

Voltage with 354 watts of load was 114. After the tweak that was enough to boost voltage to 125. As I loaded it down voltage sagged to the 117 volt level. I'm pleased to say the least!

Input voltage testing was done with a variac for resetting the trigger voltage. The OEM numbers had not changed.

I found out that at 75 volts the Sola clicks out to protect itself.

I did not try the high voltage buck.

I do have the Magnum remote set at a maximum of 24 amps.

Thanks for all the suggestions.

I did not hear back from Sola.

There is........

Always the certainty of removing the cover and taking four or five images of the loaded circuit board, then bring the images here.

Can't hurt, right?