[C320-list] A-B Cold Machine: power consumption

[Warren Updike]

The items below have a measurable affect on the duty cycle.

1. Outside Air Temperature; California water is about 66-70 degrees where we
sail and the port locker where the condenser is stays cool.  Our water in the Chesapeake can get over 80deg. I have a spacer that keeps the port locker open to vent heat from the compressor.
2. How full the refer is, the fuller the better. Agreed.
3. How tight a seal the top has, older boxes on the C-320 did not have a
good seal.  I replaced the seals last year.
4. Did you start with allot of frozen items.  We usually freeze orange juice
and water and place these at the bottom of the box, creates a heat sink. I usually place a 10lb ice block at the bottom and keep other frozen items in the same area.
5. Are you placing a cover on top of the food to cerate a seal between the
food and the cover; we use a camping ground cover. When no it use, we put one of our closed cell cushions on top over the freezer side (we only use half the cushions in the cockpit.)
6. Do you plan only to open the box a few times a day. Well, as little as possible.
7. Etc. We use one of those battery operated little fans.  I think that helps.

Given all of that we seem to use 40-50 amps a day for the refer but 
P.S. It was suggested to set the unit to max cold when you are motor
sailing, that is a great idea. When motoring or on shore power I set the thermostat at 4 which seems to be quite enough for our box.  Once underway and no motor, I dial the thermostat back to 2 which seems to keep everything cold and frozen.  After being out for 3 weeks, we still had about half of the 10lb ice block left. 

I would guess I'm using somewhat more than your 40-50 amps, say about 60 in a 24 hour period. That is a duty cycle of 36% which is in the area of what I thought it would be.

Warren & Pattie Updike
C320, #62, 1994, "Warr De Mar"
Frog Mortar Creek, Middle River
Chesapeake Bay