John
I assume you have an engine-driven system such as mine. I suggest that you invest in the kollman marine book. It has everything in there that you need to know.

http://www.kollmann-marine.com/book.html

The schrader valves are are described in the book. As I remember, they are full counter-clockwise for normal operation, full clockwise for closed, and half-way in-between for service. You can use a box wrench to adjust them, but there’s a special ratcheting tool that is used for these valves that makes service easier. I don’t remember where I got mine. I did a web search and came up with this.
http://www.tooltopia.com/index.asp?PageAction=VIEWPROD&ProdID=5237&CAWELAID=81311982

If you properly connect your gauges and open the service valves part-way, you should see high pressure on the high side and partial vacuum on the low side. The exact pressure settings are temperature dependent and are described in the book as are failure symptoms. The pressure gauges should move slightly over time, but should not cycle on and off unless the box is very cold. If they cycle with a warm box, you have water in your system. If you see bubbles in your sight-glass and the gauges both show pressure and vacuum yet the system doesn’t run cold, you are probably low on refrigerant. This is very common on engine-driven systems. Over the winter, the seals on the compressor may leak. I sometimes close my schrader valves over the winter to keep the charge from leaking out. You must remember to open them all the way before running your system however.

If you have R-134, add a can of refrigerant. This can be purchased at Walmart. You may need a tap-a-can and hose to connect to your gauges. Take a look at the hose fittings on your gauges to see what kind of hose adapter you need for a can. Most automotive stores will have what you need if you can’t find it at Walmart.

Keep an eye on the sight glass as you add refrigerant. If it starts running without bubbles, stop adding refrigerant. I haven’t been able to figure out precisely how much refrigerant to add. I find that if the system is low, a can or two will fix it. There’s a reservoir in the condenser that can hold a few pounds. When properly charged, the plates will start to freeze in about 30 minutes. After an hour or so, the box is cold. It may take a couple of hours or more to completely freeze the plates if the box is warm, but I usually don’t bother to run the engine that long unless I’m headed somewhere.

Feel free to call me if you have questions.

—
Rich Carter
603-493-3330

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Original message

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Does the unit have a low pressure cut off switch. IF there isn't enough pressure the system won't activate. When you hook up your guages you should get a reading of about 70 on the high and low side when the system is idle. You got that to start with?

Chuck

On 5/27/08, Indulgence < ([email][/email])> wrote:

Hello,

The boat is in the water and I am almost done! After spending the weekend refinishing teak, I decided to test out my fridge…lots of hissing, bubbles in the view glass but no cold! I ran the engine at idle for 30+ minutes but still no cold.

I suspect that I have a small leak and need to recharge the unit (I had it recharged last year when I couldn't figure out how to do it). I must be missing something…I have the gauges and 134a…I connect the high and low pressure lines to the schrader valves…and nothing.

How long does it take? Do I close off the valves so it is only pulling from the can of refrigerant? Do I leave it open so it is pulling from both the low pressure line and can?

Suggestions on to recharge an engine drivent refrigeration system would be appreciated. Thanks.

John Sommer
Indulgence #179
Portland, ME

Post generated from Pearson424 Forum using Mail2Forum

Slow down and get a good booker like one of Calders before you get
yourself in trouble. Also don’t forget that someone can turn you in for
a $25,000+ fine if you are mishandling refrigerants. (Getting an EPA
certification is an easy thing to do by the way). Older Pearson refrig
systems don’t run 134a. Mixing the refrigerants will create a real
problem. Over charging can really damage your compressor. Take care.

Pete

Indulgence wrote:

Hello,

The boat is in the water and I am almost done! After spending the
weekend refinishing teak, I decided to test out my fridge…lots of
hissing, bubbles in the view glass but no cold! I ran the engine at
idle for 30+ minutes but still no cold.

I suspect that I have a small leak and need to recharge the unit (I
had it recharged last year when I couldn’t figure out how to do it). I
must be missing something…I have the gauges and 134a…I connect the
high and low pressure lines to the schrader valves…and nothing.

How long does it take? Do I close off the valves so it is only pulling
from the can of refrigerant? Do I leave it open so it is pulling from
both the low pressure line and can?

Suggestions on to recharge an engine drivent refrigeration system
would be appreciated. Thanks.

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John Sommer
Indulgence #179
Portland, ME

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