Charge R134 without a scale
Hi
I know that a scale can delivery a precise refrigerant charge.
However many of my students cannot afford for a scale.
I would like to improve a technique that I learnt years ago still in R12 times.
How can I charge R134 in a domestic fridge without a scale using only the manometer as a reference ?
Could anybody describe it step by step right after the vacuum step ?
Moises
Re: Charge R134 without a scale
Acrisoft, If u can mesure subcooling 5...8K I suppose it is correct. Sorry, I'm not domestic frige specialist...
Re: Charge R134 without a scale
easier ways i find is sweating of suction pipe with a clampmeter testing comp run amps but on a domestic you could charge on a standing pressure or and dont laugh during my junior years mothers bathroom scales they lasted bloody years but not so good on a small difference my lastest set of scales is 1 gram acuracy i think the bathroom scales depended on time of day and no battery to change
Re: Charge R134 without a scale
use 1kg bottles and baking scales- rated for 2kg,small,cheap,and light too.
Re: Charge R134 without a scale
Re: Charge R134 without a scale
Re: Charge R134 without a scale
Quote:
Originally Posted by
Acrisoft
Hi
I would like to improve a technique that I learnt years ago still in R12 times.
How can I charge R134 in a domestic fridge without a scale using only the manometer as a reference ?
Could anybody describe it step by step right after the vacuum step ?
Moises
That is wrong technique and you cannot improve it.
You cannot correctly charge with manometers only. You need thermometers.
According to Danfoss service literature, you should charge to 4-7K of evaporator superheat.
http://i42.tinypic.com/34hvsph.jpg
Re: Charge R134 without a scale
Quote:
Originally Posted by
AlexG
Acrisoft, If u can mesure subcooling 5...8K I suppose it is correct. Sorry, I'm not domestic frige specialist...
Charging to subcooling is only with TXV systems. Domestics are 99% cappilary tube and charging is done by superheat or by weight.
Re: Charge R134 without a scale
Can you afford recovery machines,do you have them ?