recharging an zanotti msp123t0305f

[jtq4u]

Hi all,
my father in law has just bought a zanotti msp123t0305f from a reclaim yard. It was all in bits and he has now remade all the pipework from the two parts of the unit. From looking through your forum I think it takes 404a gas.

Is this something we can get hold of and recharge it our selves (it's not like we have a problem discharging it as the system is empty because he has remade the pipes). could we just get the gas and squirt it in the inlet (like a large tyre valve). DOes one have to suck out the air from the system as the new gas goes in? Do We need to add oil to the system (as one does when regasing a car).

Thanks

James

[Crypton]

If it takes 404a ring up any refrigeration company near you and they will sell you the gas. Its a very common gas you will have no problem getting it. My question for you is how do you post a thread? My head is wrecked I cant find what way you go about it.

[Brian_UK]

Hi all,
my father in law has just bought a zanotti msp123t0305f from a reclaim yard. It was all in bits and he has now remade all the pipework from the two parts of the unit. From looking through your forum I think it takes 404a gas.

Is this something we can get hold of and recharge it our selves (it's not like we have a problem discharging it as the system is empty because he has remade the pipes). could we just get the gas and squirt it in the inlet (like a large tyre valve). DOes one have to suck out the air from the system as the new gas goes in? Do We need to add oil to the system (as one does when regasing a car).

Thanks

JamesAny advice given would encourage you to break the law so be careful with what you do with it.

Best bet is to locate your local refrigeration tech and get him to recharge it for you.

[Crypton]

The system has to be pressure tested and leak tested with nitrogen once you have achived this you have to let the nitrogen out and vac out any moisture in the system.using a torr gauage you can see the state of the vac when satisfied with manufacture spec charge the system using refrigeration gauges. You need the tools mate your probably better off paying some refrigeration eng to do it for you...

How do you post a thread on main page????

[Brian_UK]

:off topic:

How do you post a thread on main page????

Hi,


1, Click on "FORUMS" button on blue line under the site name, top left.

2. Scroll down and click on a forum section title that you want to start your thread in.

3. Click on "NEW THREAD" at the top of the section list.

[jtq4u]

thanks for the advice all. I have suggested he starts by getting a quote for a pro to do it, however if that turns out to be very expensive would one of the following work. Bear in mind that as I understand it r404a is not harmful to the environment (so I read on a data sheet - true?).

He has already pressure tested the system, as an experianced plumber this wasn't a problem.

1. I can modify another old fridge compressor to use as a vaccume pump to perform the vaccum task. We can obtain a vaccum gauge.

2. alternatively Could we not leave one of the valves open and waste some r404a gas by squirting it in the other valve for a while - thus expelling the existing air from the system. then close the other valve and pressurize the system (we can obtain a pressure gauge for it easily enough).

does either of those approaches work?

Cheers

James

[jtq4u]

thanks for the comments. Why would it be illegal, as I understand it r404a is not a cfc and so not detrimental to the enviornment.

I have suggested two approaches as an append to my post, which could be used to vaccum the water out of the system. Would they work do you think. If doing it myself is illegal - why?

Thanks

James

[nike123]

thanks for the comments. Why would it be illegal, as I understand it r404a is not a cfc and so not detrimental to the enviornment.

[/URL][url]http://www.acrib.org.uk/M6LEVN80958 (http://www.fluorocarbons.org/en/debate/regulatory_developments/f_gas_regulation.html#REG)


I have suggested two approaches as an append to my post, which could be used to vaccum the water out of the system. Would they work do you think.

No they wont work.
Compressor is not suitable for vacuum drying since it cannot achieve vacuum level needed to water in system boil and evacuate. It need purpose made vacuum pump (double stage rotary vane of at least 50 microns or lower end vacuum).

Purging is against the law and it cannot remove moisture and non-condensables, since gas you purging with, doesn't carrying magic screen in front of self. It mixes with contaminants in system.

[jtq4u]

thanks for the advice I am finding it very interesting and learning a lot. So It actually causes the water to boil by lowering the pressure (seen that done in the lab but didn't realise it was the approach used here). Very cool.
Anyhow looks like I can get a vaccum pump for about £150 new
item number 310118698626 on ebay (can paste it into the search field)
then just need to get pipes etc.
We always take the approach at the farm of comparing the cost of buying some equiptment to do something our self or calling someone in to do it.

So it will be interesting to see what people we call quote to fill this system with gas. If it's in excess of £200 + whatever the gas costs then we might as well give it a go ourselves. Hopefully we can get hold of the service manuels so as to get the right pressure settings (eg level of vaccum and pressure to gas it up to). Plus I wonder if it needs refigerant oil like car ones do!

Cheers for all the helpful advice so far

James

[nike123]

When you vacuum drying/evacuating system with vacuum pump you need instrument which will tell you what vacuum you achieved. It is called micrometer (it measures microns of Hg column) or vacuum meter.

http://farm4.static.flickr.com/3030/2817747757_0dc0d6b752_o_d.jpg

That is additional 100 pounds or more!
Then you need set of gauges and hoses to be able to evacuate/charge and measure suction and discharge pressure. That is additional expense.
Next you need accurate pipe thermometer (+-0,5K) to measure pipe temperatures to be able to calculate superheat and subcooling because pressures are meaningless (http://www.refrigeration-engineer.com/forums/showthread.php?t=11383&highlight=pressures+meaningless). Also you need WB and DB thermometers for measuring air temperature (or hygrometer) to be able to measure air temperatures and humidity.
And, you need to know how to charge system corectly without overcharging /undercharging and not to damage system with incorrect charging procedure.
Last, you need to evaluate performance to know is it working as it should work, or you stil have problem in system.

[jtq4u]

one other useful bit of info (even if i can't get it my self) is how much does r404a cost and does anyone know how much our unit will need??

Thanks!

[jtq4u]

thanks for the vaccum gage info. they do look expensive to go to that level of granularity.. cheap ones don't go to that range, even though some claim to go to -30 mercury they are rounding up and when you look at their details it's only really about 29.6 or 7500 microns. I am guessing you use digital ones.

[nike123]

thanks for the vaccum gage info. they do look expensive to go to that level of granularity.. cheap ones don't go to that range, even though some claim to go to -30 mercury they are rounding up and when you look at their details it's only really about 29.6 or 7500 microns. I am guessing you use digital ones.
http://www.ryanairconspares.com/vg64-refco-digital-gauge-p-543.html

[jtq4u]

looking like we will have to pay someone then, what a pity - you can do a 'good enough' job on a car system.
Wonder how much it will cost.

[Brian_UK]

One other comment....

Your plumber pressure tested it for you apparently.

How did he perform the strength test and pressure test?

[icecube51]

if there is something elegal going on, here's the place and time to be.my friend,you are like a bankrobber ho is exploring and fisching to heyst his next victim.you are messing whit gasses,playing whit oil,no nowledge, no tools........where is this going to end

ice

[Crypton]

Thanks Brian, Only seeing your reply now....

[Devsan]

One other comment....

Your plumber pressure tested it for you apparently.

How did he perform the strength test and pressure test?

probally used water to pressure test the system :eek:

dear god the sooner our trade clamps down on numpties like this the better.

JUST PAY A Company TO RECHARGE IT FOR YOU:rolleyes: