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UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
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#1
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R600a in Freezer
Hello!
I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? Is it to do with the pressure on the suction side when the compressor is running? (It is working fine now by the way) Thanks for any pointers :-) -- Toby... Remove pants to reply |
#2
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R600a in Freezer
"Toby" wrote in message ... Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? Is it to do with the pressure on the suction side when the compressor is running? (It is working fine now by the way) Thanks for any pointers :-) How did you recharge it? |
#3
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R600a in Freezer
On 07/04/2013 18:24, Mr Pounder wrote:
"Toby" wrote in message ... How did you recharge it? I bought the following things Manifold gauge set http://www.ebay.co.uk/itm/290496320732 Small cylinder of R600a refrigerant http://www.ebay.co.uk/itm/380597193357 Valve for the cylinder http://www.ebay.co.uk/itm/110982392239 I already had a 0-500g set of scales like this http://www.ebay.co.uk/itm/181112007479 The freezer already had two service valves fitted, so I didn't need to fit any - if they were not there, I would have bought a line tap like this http://www.ebay.co.uk/itm/130577043065 and fitted it to the suction line (that is marked on the compressor usually, if not, it is the thicker pipe that comes from inside the freezer, not the one that goes to the condenser on the back). I connected the blue hose to the blue side of the manifold, and the other end of the blue hose to the the suction side of the compressor in the freezer. I then connected the red hose to the the second tap of the middle connection on the manifold (not the red side of the manifold), and the other end to free air (R600a is flammable, so it needs to vent outside) The yellow hose to the bottom connector of the middle port of the manifold, and the other end the the valve on top of the R600a cylinder with the cylinder valve off. I then opened the blue tap to let out the gas that was in the freezer (out of the red hose), when it stopped hissing I let a small amount of R600a out of the cylinder to purge the yellow hose, then connected the free blue hose to the vacuum pump. Then I turned on the vacuum pump (old compressor) and opened the blue valve, and left it sucking for about 30 minutes. With the vacuum pump still running I turned off the blue valve and then disconnected the red hose (it connects to a self closing valve on the manifold) This then left me with all the connected hoses and the freezer pipework under vacuum. I left it like this for about 30 minutes, and it was still showing the same vacuum, so if there is a leak, it isn't a big one! I placed the R600a cylinder on the scales, and hung the manifold in a way so the cylinder wasn't wanting to tip over, and the weight of the hose was constant With the cylinder on the scales, I then opened the valve on the cylinder and zeroed the scales. I then turned the freezer on, and when I heard the compressor kick in, I opened the blue valve to let the compressor pump the gas into the freezer. The data plate states it takes 54g of R600a, so I watched as the scales slowly climbed up - when it got to about 32g, the damn scales auto-powered off, so I quickly turned the blue valve off, (I also connected the red hose to the red side of the manifold and the other end to the high side of the compressor - this wasn't really necessary, I just wanted to see what the pressure was showing on the high side when the compressor was running, I also warmed the cylinder up a bit, as the rate of flow had been trailing off because the cylinder was getting really cold) I then reset the scales, and carried on. When I had put 54g in, I shut the blue valve. I then put a bit more in (5g), to allow for some refrigerant in the hoses, and I had read about the suction side should read around 0 when it is full, and as it was still pulling a vacuum, I put some more in. I am not sure about this part, hence the question, and figured I could just let some out, plus I suspect it has a very slow leak. Total that left the cylinder was 60g. I am obviously not a refrigeration engineer (hence the original question!) so I may not have done this correctly, but after reading up on it for quite a bit, I think I did a fair job, a proper vac pump would have been ideal, but I figured the system should be pretty clean as it was still under some pressure, and I figured the old freezer compressor I had would do in this case. Ideally the filter/dryer should be replaced, but I don't have any brazing or lokring tools to do this (yet!) - The Lokring stuff looks really easy to use, but damn expensive compared to brazing rods and a mapp gas torch. And I would want to purge the lot with nitrogen if I welded anything on it too, and I don't have any nitrogen either... If you use an old compressor as a vac pump, the output tends to spit oil, I found this out when I fired it up on my desk inside, which wasn't the best place to do spray oil everywhere in hindsight (the fact I had moved the compressor 5 minutes before probably increased the amount it spat out too), so to overcome this, I connected a few meters of clear pipe to the output, and scrunched up a tissue and tied it to the end this seems to have done the trick The oil sprays up the pipe to start with (I kept almost all of it vertical), but as the other end is then under vacuum, quite quickly the oil just ran back down into the compressor as there isn't any air blowing out the port. -- Toby... Remove pants to reply |
#4
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R600a in Freezer
Toby wrote:
Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? It's obvious, just weigh the whole freezer. ;-) Seriously, with a refrigerant that's probably part liquid, part gas, a pressure reading will be of no use to you. That's why you put a weighed quantity in rather than filling to a pressure. Tim |
#5
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R600a in Freezer
On 07/04/2013 20:52, Tim+ wrote:
Toby wrote: Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? It's obvious, just weigh the whole freezer. ;-) Seriously, with a refrigerant that's probably part liquid, part gas, a pressure reading will be of no use to you. That's why you put a weighed quantity in rather than filling to a pressure. Tim I could weigh the whole freezer, but would then have to either track the weight of the contents too, and also take into consideration the weight of any frost build-up too :-) I can see the pressure readings while off will be of no use, as the pressure will be the same no matter how much refrigerant is in there (assuming there is some in liquid state), but when running, the high and low sides should behave in a particular way depending on the type of refrigerant and how much there is in there - I think it has something to do with a pressure temperature chart like this http://refspecs.co.nz/cms/uploads/fi...PT%20Chart.pdf But I am not sure... As the freezer appears to be working fine with the suction side at 0 when running, maybe that is the answer... -- Toby... Remove pants to reply |
#6
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R600a in Freezer
Toby wrote:
On 07/04/2013 20:52, Tim+ wrote: Toby wrote: Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? It's obvious, just weigh the whole freezer. ;-) Seriously, with a refrigerant that's probably part liquid, part gas, a pressure reading will be of no use to you. That's why you put a weighed quantity in rather than filling to a pressure. Tim I could weigh the whole freezer, but would then have to either track the weight of the contents too, and also take into consideration the weight of any frost build-up too :-) Well, I did say "obvious", not "easy". ;-) I can see the pressure readings while off will be of no use, as the pressure will be the same no matter how much refrigerant is in there (assuming there is some in liquid state), but when running, the high and low sides should behave in a particular way depending on the type of refrigerant and how much there is in there - I think it has something to do with a pressure temperature chart like this http://refspecs.co.nz/cms/uploads/fi...PT%20Chart.pdf But I am not sure... As the freezer appears to be working fine with the suction side at 0 when running, maybe that is the answer... Your seem to be well on your way to becoming a refrigeration expert anyway so I suspect you know more about the subject than 99% of the folk here (me included). ;-) Tim |
#7
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R600a in Freezer
Tim+ wrote:
Toby wrote: On 07/04/2013 20:52, Tim+ wrote: Toby wrote: Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? It's obvious, just weigh the whole freezer. ;-) Seriously, with a refrigerant that's probably part liquid, part gas, a pressure reading will be of no use to you. That's why you put a weighed quantity in rather than filling to a pressure. Tim I could weigh the whole freezer, but would then have to either track the weight of the contents too, and also take into consideration the weight of any frost build-up too :-) Well, I did say "obvious", not "easy". ;-) I can see the pressure readings while off will be of no use, as the pressure will be the same no matter how much refrigerant is in there (assuming there is some in liquid state), but when running, the high and low sides should behave in a particular way depending on the type of refrigerant and how much there is in there - I think it has something to do with a pressure temperature chart like this http://refspecs.co.nz/cms/uploads/fi...PT%20Chart.pdf But I am not sure... As the freezer appears to be working fine with the suction side at 0 when running, maybe that is the answer... Your seem to be well on your way to becoming a refrigeration expert anyway so I suspect you know more about the subject than 99% of the folk here (me included). ;-) Tim :-) been doing my homework! I was hoping there may be a proper refrigeration expert lurking to fill in the gaps :-) Also interested in a cheap leak detector for R600a and if it works on R410a then that would be great too... -- Toby... remove pants to reply |
#8
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R600a in Freezer
Toby wrote:
Tim+ wrote: Toby wrote: On 07/04/2013 20:52, Tim+ wrote: Toby wrote: Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? It's obvious, just weigh the whole freezer. ;-) Seriously, with a refrigerant that's probably part liquid, part gas, a pressure reading will be of no use to you. That's why you put a weighed quantity in rather than filling to a pressure. Tim I could weigh the whole freezer, but would then have to either track the weight of the contents too, and also take into consideration the weight of any frost build-up too :-) Well, I did say "obvious", not "easy". ;-) I can see the pressure readings while off will be of no use, as the pressure will be the same no matter how much refrigerant is in there (assuming there is some in liquid state), but when running, the high and low sides should behave in a particular way depending on the type of refrigerant and how much there is in there - I think it has something to do with a pressure temperature chart like this http://refspecs.co.nz/cms/uploads/fi...PT%20Chart.pdf But I am not sure... As the freezer appears to be working fine with the suction side at 0 when running, maybe that is the answer... Your seem to be well on your way to becoming a refrigeration expert anyway so I suspect you know more about the subject than 99% of the folk here (me included). ;-) Tim :-) been doing my homework! I was hoping there may be a proper refrigeration expert lurking to fill in the gaps :-) Also interested in a cheap leak detector for R600a and if it works on R410a then that would be great too... You can stick a bit of uv dye in the middle hose before you connect the fill bottle.You will be able to find leaks with a uv light. |
#9
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R600a in Freezer
On Apr 7, 6:11*pm, Toby wrote:
Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? Is it to do with the pressure on the suction side when the compressor is running? (It is working fine now by the way) Thanks for any pointers :-) -- Toby... Remove pants to reply It's down to the pressure readings. I don't know the values for these newer refrigerants. |
#10
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R600a in Freezer
On Apr 7, 11:40*pm, Toby wrote:
Tim+ wrote: Toby wrote: On 07/04/2013 20:52, Tim+ wrote: Toby wrote: Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? It's obvious, just weigh the whole freezer. ;-) Seriously, with a refrigerant that's probably part liquid, part gas, a pressure reading will be of no use to you. *That's why you put a weighed quantity in rather than filling to a pressure. Tim I could weigh the whole freezer, but would then have to either track the weight of the contents too, and also take into consideration the weight of any frost build-up too :-) Well, I did say "obvious", not "easy". ;-) I can see the pressure readings while off will be of no use, as the pressure will be the same no matter how much refrigerant is in there (assuming there is some in liquid state), but when running, the high and low sides should behave in a particular way depending on the type of refrigerant and how much there is in there - I think it has something to do with a pressure temperature chart like this http://refspecs.co.nz/cms/uploads/fi...PT%20Chart.pdf But I am not sure... As the freezer appears to be working fine with the suction side at 0 when running, maybe that is the answer... Your seem to be well on your way to becoming a refrigeration expert anyway so I suspect you know more about the subject than 99% of the folk here (me included). ;-) Tim :-) been doing my homework! I was hoping there may be a proper refrigeration expert lurking to fill in the gaps :-) Also interested in a cheap leak detector for R600a and if it works on R410a then that would be great too... -- Toby... remove pants to reply In domestic refrigerators a small surplus of liquid gas remains in the bottom of the compressor housing during operation. When this has all leaked out there is a radical change in the gas pressures in the system Commercial freezers/fridges usually have a "condensing unit" that incorporates a reservoir for liquid gas, as well as the compressor and condenser. They sometimes have a sight glass incorporated. So it takes longer for leaks to have any effect. http://en.wikipedia.org/wiki/Economizer#Refrigeration |
#11
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R600a in Freezer
On Apr 7, 11:40*pm, Toby wrote:
Tim+ wrote: Toby wrote: On 07/04/2013 20:52, Tim+ wrote: Toby wrote: Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? It's obvious, just weigh the whole freezer. ;-) Seriously, with a refrigerant that's probably part liquid, part gas, a pressure reading will be of no use to you. *That's why you put a weighed quantity in rather than filling to a pressure. Tim I could weigh the whole freezer, but would then have to either track the weight of the contents too, and also take into consideration the weight of any frost build-up too :-) Well, I did say "obvious", not "easy". ;-) I can see the pressure readings while off will be of no use, as the pressure will be the same no matter how much refrigerant is in there (assuming there is some in liquid state), but when running, the high and low sides should behave in a particular way depending on the type of refrigerant and how much there is in there - I think it has something to do with a pressure temperature chart like this http://refspecs.co.nz/cms/uploads/fi...PT%20Chart.pdf But I am not sure... As the freezer appears to be working fine with the suction side at 0 when running, maybe that is the answer... Your seem to be well on your way to becoming a refrigeration expert anyway so I suspect you know more about the subject than 99% of the folk here (me included). ;-) Tim :-) been doing my homework! I was hoping there may be a proper refrigeration expert lurking to fill in the gaps :-) Also interested in a cheap leak detector for R600a and if it works on R410a then that would be great too... -- Toby... remove pants to reply In days of yore when freon gas was used, there were special blowlamps for detecting leaks that had a rubber pipe attached. The end of the pipe was used to detect leaks, the flame changed to a green colour. But that wouldn't work on butane. |
#12
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R600a in Freezer
"Toby" wrote in message ... On 07/04/2013 18:24, Mr Pounder wrote: "Toby" wrote in message ... How did you recharge it? I bought the following things Manifold gauge set http://www.ebay.co.uk/itm/290496320732 Small cylinder of R600a refrigerant http://www.ebay.co.uk/itm/380597193357 Valve for the cylinder http://www.ebay.co.uk/itm/110982392239 I already had a 0-500g set of scales like this http://www.ebay.co.uk/itm/181112007479 The freezer already had two service valves fitted, so I didn't need to fit any - if they were not there, I would have bought a line tap like this http://www.ebay.co.uk/itm/130577043065 and fitted it to the suction line (that is marked on the compressor usually, if not, it is the thicker pipe that comes from inside the freezer, not the one that goes to the condenser on the back). I connected the blue hose to the blue side of the manifold, and the other end of the blue hose to the the suction side of the compressor in the freezer. I then connected the red hose to the the second tap of the middle connection on the manifold (not the red side of the manifold), and the other end to free air (R600a is flammable, so it needs to vent outside) The yellow hose to the bottom connector of the middle port of the manifold, and the other end the the valve on top of the R600a cylinder with the cylinder valve off. I then opened the blue tap to let out the gas that was in the freezer (out of the red hose), when it stopped hissing I let a small amount of R600a out of the cylinder to purge the yellow hose, then connected the free blue hose to the vacuum pump. Then I turned on the vacuum pump (old compressor) and opened the blue valve, and left it sucking for about 30 minutes. With the vacuum pump still running I turned off the blue valve and then disconnected the red hose (it connects to a self closing valve on the manifold) This then left me with all the connected hoses and the freezer pipework under vacuum. I left it like this for about 30 minutes, and it was still showing the same vacuum, so if there is a leak, it isn't a big one! I placed the R600a cylinder on the scales, and hung the manifold in a way so the cylinder wasn't wanting to tip over, and the weight of the hose was constant With the cylinder on the scales, I then opened the valve on the cylinder and zeroed the scales. I then turned the freezer on, and when I heard the compressor kick in, I opened the blue valve to let the compressor pump the gas into the freezer. The data plate states it takes 54g of R600a, so I watched as the scales slowly climbed up - when it got to about 32g, the damn scales auto-powered off, so I quickly turned the blue valve off, (I also connected the red hose to the red side of the manifold and the other end to the high side of the compressor - this wasn't really necessary, I just wanted to see what the pressure was showing on the high side when the compressor was running, I also warmed the cylinder up a bit, as the rate of flow had been trailing off because the cylinder was getting really cold) I then reset the scales, and carried on. When I had put 54g in, I shut the blue valve. I then put a bit more in (5g), to allow for some refrigerant in the hoses, and I had read about the suction side should read around 0 when it is full, and as it was still pulling a vacuum, I put some more in. I am not sure about this part, hence the question, and figured I could just let some out, plus I suspect it has a very slow leak. Total that left the cylinder was 60g. I am obviously not a refrigeration engineer (hence the original question!) so I may not have done this correctly, but after reading up on it for quite a bit, I think I did a fair job, a proper vac pump would have been ideal, but I figured the system should be pretty clean as it was still under some pressure, and I figured the old freezer compressor I had would do in this case. Ideally the filter/dryer should be replaced, but I don't have any brazing or lokring tools to do this (yet!) - The Lokring stuff looks really easy to use, but damn expensive compared to brazing rods and a mapp gas torch. And I would want to purge the lot with nitrogen if I welded anything on it too, and I don't have any nitrogen either... If you use an old compressor as a vac pump, the output tends to spit oil, I found this out when I fired it up on my desk inside, which wasn't the best place to do spray oil everywhere in hindsight (the fact I had moved the compressor 5 minutes before probably increased the amount it spat out too), so to overcome this, I connected a few meters of clear pipe to the output, and scrunched up a tissue and tied it to the end this seems to have done the trick The oil sprays up the pipe to start with (I kept almost all of it vertical), but as the other end is then under vacuum, quite quickly the oil just ran back down into the compressor as there isn't any air blowing out the port. All I can say is VERY well done. |
#13
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R600a in Freezer
On Sunday, April 7, 2013 6:11:34 PM UTC+1, Toby wrote:
Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? Is it to do with the pressure on the suction side when the compressor is running? (It is working fine now by the way) Thanks for any pointers :-) I guess you could put a how-to on the wiki if you like NT |
#15
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R600a in Freezer
On Monday, April 8, 2013 10:24:21 PM UTC+1, Toby wrote:
On 08/04/2013 11:57, wrote: I guess you could put a how-to on the wiki if you like Good idea - Done! http://wiki.diyfaq.org.uk/index.php?..._%28R600a%2 9 nice one NT |
#16
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R600a in Freezer
On 08/04/2013 23:02, wrote:
On Monday, April 8, 2013 10:24:21 PM UTC+1, Toby wrote: On 08/04/2013 11:57, wrote: I guess you could put a how-to on the wiki if you like Good idea - Done! http://wiki.diyfaq.org.uk/index.php?..._%28R600a%2 9 nice one NT Can I link to a file but use a custom word, rather than it showing as Media:FILENAME.PNG ? -- Toby... Remove pants to reply |
#17
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R600a in Freezer
Toby wrote:
On 08/04/2013 11:57, wrote: On Sunday, April 7, 2013 6:11:34 PM UTC+1, Toby wrote: Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? Is it to do with the pressure on the suction side when the compressor is running? (It is working fine now by the way) Thanks for any pointers :-) I guess you could put a how-to on the wiki if you like NT Good idea - Done! http://wiki.diyfaq.org.uk/index.php?..._%28R600a%2 9 hydrocarbons are a bit more forgiving of moisture than other refrigerants (although better to not have any) I connect both red and blue hoses and leave them connected through the whole operation and just do every thing else through the yellow hose. ie vent gas, connect to vac pump,connect to charge cylinder etc. I usually put a bit of uhf dye in yellow hose just before connecting charge cyl (saves having to buy expensive equipment to inject dye under pressure). This allowes you to look for leaks with uv light later. |
#18
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R600a in Freezer
On Mon, 08 Apr 2013 23:08:37 +0100, Toby wrote:
Can I link to a file but use a custom word, rather than it showing as Media:FILENAME.PNG ? http://www.mediawiki.org/wiki/Help:Images -- Cheers Dave. |
#19
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R600a in Freezer
On Monday, April 8, 2013 11:08:37 PM UTC+1, Toby wrote:
On 08/04/2013 23:02, wrote: On Monday, April 8, 2013 10:24:21 PM UTC+1, Toby wrote: On 08/04/2013 11:57, wrote: I guess you could put a how-to on the wiki if you like Good idea - Done! http://wiki.diyfaq.org.uk/index.php?..._%28R600a%2 9 nice one NT Can I link to a file but use a custom word, rather than it showing as Media:FILENAME.PNG ? Yes, but its unclear what you mean. Please explain If you mean words that show up when you mouse them, see http://wiki.diyfaq.org.uk/index.php?title=Spanner for picture coding If you mean linking to a pic file, you can create a webpage with just that pic on it and call it whatever you want. Also what the webpage shows and what it links to can be different, eg [[con job|get rich]] PS its recommended to only capitalise the first word of page titles, otherwise searches cause problems and linking is slower. NT |
#20
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R600a in Freezer
On 07/04/2013 18:11, Toby wrote:
Hello! I have been given a freezer (Hotpoint FZ150) that wasn't working properly, (after being turned on for a while, it would lock out and alarm because it was not getting cold enough) - it had the signs of low refrigerant, so I bought a set of gauges, and that confirmed it was indeed extremely low, pulling down to about 18inHg on the suction side when running. So, I bought some R600a refrigerant and then used an old freezer compressor to vacuum the system out (after venting what little R600a there was outside (As it is just butane, this is OK, apparently) The old compressor got it down to just over 20inHg, which I was happy with for a DIY job :-) My question is, how do I know if there is enough refrigerant in the system if I check it at a later date without having to wait for it to be so low it stops cooling and alarms? I weighed in the amount it stated I needed on the data plate, but if it does need topping up at a later date (which I assume is likely if there is a small leak somewhere (which I will try to find)) then how do I tell how much is in there at any given time? Is it to do with the pressure on the suction side when the compressor is running? (It is working fine now by the way) Thanks for any pointers :-) Just as an update to this, the freezer ran put of gas again after about a week, and after much searching, I found a leak on the pipe joint between the capillary tube, and the evaporator (inside the freezer) The evaporator is aluminium, so when I tired to braze the connection, I melted the aluminium pipe a bit :-( (Original was crimped, with some glue type stuff too.) I have now jointed it with J-B Weld, as the pressures are not very high with R600a, so once that has fully set, I will see if it still leaks! -- Toby... Remove pants to reply |
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