GBM wrote:
What is the best way of measuring the power drawn by a boat's refrigeration
unit?


What type is it? Danfoss or big DC compressor? AC? Holding plate?

Is there a way to do this without any expensive instruments?

I was thinking of installing an ammeter in the line to the compressor to
determine the current draw, but manufacturer does not recommend this.

Why? This seems odd.

Even
with that, I would need an hour meter or some such device to know how often
and for how long the compressor runs.

That's just what I do - I have a "2 bank" amp-hour meter, actually a
Link 2000, which I use in the normal way for the first bank, but I
measure the fridge usage with the second bank.

This is not a cheap solution, but if you have AH concerns, maybe you
want at least a simple amp-hour meter that you could use in either mode.




I would like to test existing installation, then add some "temporary"
insulation to the inside of the box and then test again to see what
improvement I might get if I added permanent insulation.