Danfoss NL11F

[xt0m]

Mornings

Um, I'm gettin a refill on my NL11F (originally a Mach II Std., now modded by tim-)
How much r404 should be put on there?

I dont mind overcharging a bit and finding the proper "noise-free" level myself.

Thanks

[killermiller]

Was there a leak or something? PM Tim, he may have kept a record or may remember.

[xt0m]

Tried asking him via WLM a while back, the numbers I got were "16/0,3bar"
(16bar highside, 0,3suction during load)

[xt0m]

How much r404 is usually filled onto an NL11F?

[Jack]

Until the superheat and subcooling is right.

[Xeon th MG Pony]

Until the superheat and subcooling is right.

I am proud to see that statement!

That is the correct way!

with a cap tube, you charge untill superheat is around 20 degrees F

With a TXV you charge to about 6 degrees F subcooling.

[tim-]

xtom:
yes you asked me and i told you an honest answer, I don't know how much in weight. I have a refrigerant scale but it's only graded with 50grams interval, not accurate for this size of systems.. i informed you that i had 16/0.3 bar(g) during load.

killermiller:
no it's just that xtom did laborate by letting gas out and took a little to much out.

[killermiller]

I wasn't implying anything, my friend.

I was worried that he was wanting to top it off like a cup of soda.

[xt0m]

with a cap tube, you charge untill superheat is around 20 degrees F
With a TXV you charge to about 6 degrees F subcooling.

[star882]

Look up subcooling and superheat.

[PhilippF]

I usually fill a unit by measuring subcooling under load and also watching HP under load.

You mount a Thermocoupler to the lower exit of the condenser. Then you look up the scale on your gauge that reads the LP temps of 404a. The difference between the two is your subcooling which should be between 2 and 5 degrees C. Also HP should stay below 15.8 barg for the NL11.

The you apply a load tester and start up the unit. Then you start adding refrigerant until the temp drops rapidly and if it has reached -40C or so, you start the load tester. First at 100W, adding more refrigerant until it can hold the temps, then at 150W, adding refrigerant until it can hold the temps, then 200 and 240W, always adding refrigerant until the temp can be held.

At every step you let the unit run for 5-10 min and have a look at subcooling and HP. If the subcooling exceeds 5 Kelvin or HP exceeds 15.8 barg, you have to shorten the captube or use less load.

As the unit was already tuned by tim, ask him for which load, apply exact this load and fill up 404a until it can hold the temp at this load, you wont have to shorten the captube.

Regards,

Philipp

[xt0m]

Ah well, might have been too unspecific there.

I'm not doing the refill myself..