Re-gas AC 417a in Spain

[Paul_S123]

Re-gas AC 417a in Spain - Causes?

Hi, had someone look at my saloon ac units

They both need the gas re topped up.

He said the 417a gas is hard to get in Spain, any alternatives?

 

[jrudge]

Do bear in mind if the unit requires top up there must be a leak.

Brazed sealed systems ( fridges , boat air con) should not need top up. Cars should not but they tend to have a load of flexible pipes and slight leakage can occur - but even then there is usually a leak and they add dye to the gas to help find it.

Any time on a car ( twice) I have gone for regas there have been Leaks

 

[GSL]

Any time I have had anyone look at my boats aircon, the "go to" response is always "needs re-gassing".

I have investigated further and the system has yet to be re-gassed and is working fine, so do be sure it does need re-gassing before you let anyone proceed down this road.

Graham

 

[Paul_S123]

OK thanks

 

[superheat6k]

R417A is Du Pont / Chemours Isceon MO59. This was developed to replace R22 in direct air cooling systems. They also developed MO29 - R422D and MO99 - R438A, any of which should work fine.

Otherwise R424A was made by Elf Atochem so this could be worth a try.

Finally if the compressor is a rotary and NOT a piston compressor, R407C would be OK but ideally the oil should be changed for a Polyolester (POE) grade, e.g 32 or 68. Piston compressors in my experience do not fare well on R407C.

 

[Paul_S123]

Any time I have had anyone look at my boats aircon, the "go to" response is always "needs re-gassing".

I have investigated further and the system has yet to be re-gassed and is working fine, so do be sure it does need re-gassing before you let anyone proceed down this road.

Graham

Out of interest, and before he regasses, what were your causes.

Just to fully explain my ac woes

I have just bought the boat..so is new to me.

All the other ac units are working fine, the ones for the master cabin, guest cabins and the crew cabin blow out cold air and cool those areas down a treat. The 2 for the saloon however make zero difference at all to the temp in the saloon.

I checked the strainer and it's fine.

Water flow coming out the hull seems ok, but I have no benchmark.

All the systems share the same strainer and pump...but perhaps the smaller systems need less water than the 2 large saloon units ??

On the day of the survey a couple of months ago...the 2 saloon units threw up HPF faults (just those 2 units), but I have used them all quite intensively (albeit to no avail lol) since then and the fault has never reoccured. The HPF faults were shrugged off as having air go into the system when the boat was lifted without closing the seacock.

I checked the programming and they are in auto cool/heat mode.

They do heat the saloon if the temp is turned up on the thermostat.

What are the chances of 2 very lightly used but 12 year old units needing regassing?

 

[kashurst]

If the units will blow out warm air, if you put them into heat mode then I don't think they need re-gassing. The aircon system is a heat pump. It takes heat from one place and dumps it somewhere else. In doing so the heat extractor device gets cold. If you are running the unit to heat the saloon it's taking heat from the sea water and dumps it into the saloon. If you run the unit as air-con it takes heat from the saloon and dumps it into the sea water. So, if the heat pump can get heat from the sea and heat the saloon it must be gassed sufficiently. If the HPF fault has not returned then it was almost certainly just air in the system. Again as the saloon units will heat they must be getting seawater through the heat pump. Check the units again to just make sure the air coming out is properly warm not just circulating air in the room ( turn it up to max )

I had a problem with a Dometic aircon unit that would cool but not heat (possibly the opposite of your problem). The fault was in the aircon control module. The problem was with the temperature sensor going duff. If your control sensors are playing up they may well display that the room temp is already below the set temp so will blow air but not do any cooling. In effect the air-con thinks everything is OK. If you have an IR thermometer, measure the temperature of the air-con controller - the temp sensor is inside it close to the surface. The temp display should agree with actual measured temp.

Check what temperature the displays on the problematic thermostat/controller read as room temperature and what is the set temperature. Also over-ride the controller and put it into cooling mode only.
Also on the dometic system it was very easy to swap control panels from unit to unit - network style connector on the back of the controller just unplug it. I took a known good controller and fitted it to the system that was playing up and it then worked correctly. Solution was repair the duff controller. Check instruction manual before you start swapping bits and power it all down first. Hope this makes sense.

Edit -just had another idea to test -use a hairdryer to heat up the thermostat and see what room temp change it shows and if the aircon starts as the thermostat heats up - go easy with the hair dryer ;-)

 

[Paul_S123]

If the units will blow out warm air, if you put them into heat mode then I don't think they need re-gassing. The aircon system is a heat pump. It takes heat from one place and dumps it somewhere else. In doing so the heat extractor device gets cold. If you are running the unit to heat the saloon it's taking heat from the sea water and dumps it into the saloon. If you run the unit as air-con it takes heat from the saloon and dumps it into the sea water. So, if the heat pump can get heat from the sea and heat the saloon it must be gassed sufficiently. If the HPF fault has not returned then it was almost certainly just air in the system. Again as the saloon units will heat they must be getting seawater through the heat pump. Check the units again to just make sure the air coming out is properly warm not just circulating air in the room ( turn it up to max )

I had a problem with a Dometic aircon unit that would cool but not heat (possibly the opposite of your problem). The fault was in the aircon control module. The problem was with the temperature sensor going duff. If your control sensors are playing up they may well display that the room temp is already below the set temp so will blow air but not do any cooling. In effect the air-con thinks everything is OK. If you have an IR thermometer, measure the temperature of the air-con controller - the temp sensor is inside it close to the surface. The temp display should agree with actual measured temp.

Check what temperature the displays on the problematic thermostat/controller read as room temperature and what is the set temperature. Also over-ride the controller and put it into cooling mode only.
Also on the dometic system it was very easy to swap control panels from unit to unit - network style connector on the back of the controller just unplug it. I took a known good controller and fitted it to the system that was playing up and it then worked correctly. Solution was repair the duff controller. Check instruction manual before you start swapping bits and power it all down first. Hope this makes sense.

Edit -just had another idea to test -use a hairdryer to heat up the thermostat and see what room temp change it shows and if the aircon starts as the thermostat heats up - go easy with the hair dryer ;-)

It does..thanks. The only thing I will add is that there's 2 units in the saloon, 2 controls and they're both acting the same way.

Just checked turning them both up on the temp and they both started throwing out warm air.

Turn the temps down, the cool led lights up and they kick out room temp air.

 

[Paul_S123]

tried the hairdryer trick...set the temp to room temp, heated it up at the conttroller and it kicked on....set the module to cool only.

Neither produced cold air

 

[superheat6k]

Re: Re-gas AC 417a in Spain - Causes?

Have you identified the condensing unit that is powering the offending air handlers ?

When in cooling mode does the compressor run ?

Any oily patches anywhere on pipework joints or assemblies ?

You mention prior HPF faults - have you tried resetting a HP manual reset trip - these are a small round sensor with a reset button under a rubber cover. Something like this ...

https://www.americanhvacparts.com/p...eset-safety-switch-universal-replacement.aspx

It is also possible the reversing valve is stuck. This device changes the gas flow between the condenser (water cooled vessel) and evaporator (matrix within the indoor unit). The device has a group of pipes entering with a small solenoid on one side. There is a good explanation here ...

http://www.heatpump-reviews.com/Heat-Pump-Reversing-Valve.html

This sometimes free up with a firm jolt from a soft mallet. Check also that the solenoid coil is OK. Normally they default to cooling (solenoid off).

The fact the unit heats but doesn't cool suggest the unit is not out or even short of gas.

That said it could be a cooling only unit with electric heater elements.

Can you take some photos so I can study the equipment more closely - I can then suggest where to start looking.

 

[Paul_S123]

Re: Re-gas AC 417a in Spain - Causes?

I will start crawling about...

I have attached a schematic from the owners manual.

FYI the units are marine air vector compact circa 2006

Controlled bu Passport I/O controls

 

[Paul_S123]

Re: Re-gas AC 417a in Spain - Causes?





The pump

 

[superheat6k]

Re: Re-gas AC 417a in Spain - Causes?

View attachment 73267

View attachment 73268

The pump

View attachment 73269

You don't explain if the compressor actually runs. Therefore I am having to make some assumptions here to guide you.

If not this could be a control or fuse problem, or a low pressure switch has activated. This could happen if the system is severely short of gas.

Pic 1 The red labelled fitting marked discharge is the high pressure pipe out from the compressor. If you follow this pipe you may find a pressure sensor. But if the compressor runs then the HP trip isn't tripped.

So assuming the compressor runs does the discharge pipe get warm or very hot ?

If it doesn't run check the other pipe entering the compressor to see if it has a low pressure sensor or switch.

A quick check for pressure is to remove the cap on the red painted schraeder valve and briefly depress the tyre valve within, or better still buy yourself a basic manifold from EBay and measure the pressure. For R417A with at least some level of charge I would expect a standing pressure around 9 bar at 25C ambient around the unit. The pressure will vary up or down with the actual temperature. A good standing pressure does not mean it is fully charged but will at least mean it has some liquid refrigerant present.

eBay https://www.ebay.co.uk/itm/UK-Stock...m=232181794410&_trksid=p2045573.c100505.m3226

With a 2 gauge manifold you can check both suction and discharge as the compressor runs. I would expect the LP around 4-6 bar and HP around 15-20 bar. These pressures will vary according to the seawater temp and air temp through the evaporator (indoor coil). I suggest you only attach the hoses with the compressor off. When you are done you will lose some gas within the hoses, so avoid keep applying them.

Pic 2 is the reversing valve. The four pipes shown are the compressor discharge, compressor suction, return from evaporator, discharge to condenser. Trace out each pipe to identify where it goes. In heating mode the hot discharge routes to the evaporator (the coil passing air to the cabin or AHU). In cooling mode the hot discharge routes to the condenser (the coil being cooled by seawater).

So so assuming the compressor runs you can find out which mode the RV is in by seeing which pipe gets hot - to evaporator Heating mode, to Cond Cooling mode.

More pics showing the fine details of the pipe work from the compressor will help plus answers to the questions above.

Finally this little rotary compressor will likely work just fine on R407C, but it would be better if you could pull out at least some of the oil and replace it with a POE grade quantity for quantity, although on such a small fully piped system even a non miscible mineral based oil will still circulate sufficiently.

Do do not attempt to use R410A or R134a.

 

[Paul_S123]

Re: Re-gas AC 417a in Spain - Causes?

Hi, many thanks for everyones input. The compressor is running. I don't have a gauge, but can depress the valve.....should this be done with the compressor running or off?

The red discharge side is pretty hot, you can rest your hand on it for a few seconds.

The condenser fins and that line are cool but not really cold.

 

[Paul_S123]

Re: Re-gas AC 417a in Spain - Causes?

Just a note, I did depress the tire valve on the discharge side, with the ac off, it had what seemed a good pressure with gas plus some fluid flying out over my finger.

One point, not sure it's relevance, but would my spanish ac "engineer" have had to use this valve to determine it needed regassing. Reason I ask is was sealed with what looked like a factory seal...and didn't look like the cap had ever been removed.

 

[superheat6k]

Re: Re-gas AC 417a in Spain - Causes?

That the compressor runs rules out the possibility of an HP trip.

Is there a similar blue LP connection ? Has this been disturbed ?

What pipe from the RV is getting hot :- to Condenser or Evaporator ?

Being able to touch the pipe suggest the system might be short of gas. I would expect R417A to get the discharge at least >65oC.

What temperature is the suction pipe into the compressor. Tepid, coolish, cold and sweating or very cold perhaps forming ice ?

Better to know the suction pressure really.

 

[Paul_S123]

Re: Re-gas AC 417a in Spain - Causes?

The suction cap seal was removed.

The suction pipe is cold.

Attached photo.

 

[superheat6k]

Re: Re-gas AC 417a in Spain - Causes?

The cold pipe shown is the pipe from the evaporator, so the reversing valve must be in the cooling mode, which is what you desire, so we have now eliminated the RV as an issue. So is the pipe shown as 'Cold' forming dew or frost ?

Also what is the air temperature in and out of the cooler matrix where the pipe emerges ?

Is the fan on the cooler matrix running ?

To get further with this fault analysis I really need temperatures. Can you obtain a thermometer ?

An A/C guy may establish these temperatures with his hand, and often this appears that he is diagnosing things by magic, and some like you to think this.

However, I am coming to the conclusion his diagnosis is likely the correct one. That said gas doesn't just leave a system, it has to leak out. Putting it back in without finding where it has been lost is a short term fix, and is not in your interests as you will be back in a month or so (or at the start of next season perhaps) to repeat the regas.

I would get a powerful torch out and examine every pipe for signs of a leak - oiliness is the commonest sign of a leak.

Interesting that this unit was supplied new on R417A looking at its dataplate.

 

[Paul_S123]

Re: Re-gas AC 417a in Spain - Causes?

The cold pipe shown is the pipe from the evaporator, so the reversing valve must be in the cooling mode, which is what you desire, so we have now eliminated the RV as an issue. So is the pipe shown as 'Cold' forming dew or frost ?

Also what is the air temperature in and out of the cooler matrix where the pipe emerges ?

Is the fan on the cooler matrix running ?

To get further with this fault analysis I really need temperatures. Can you obtain a thermometer ?

An A/C guy may establish these temperatures with his hand, and often this appears that he is diagnosing things by magic, and some like you to think this.

However, I am coming to the conclusion his diagnosis is likely the correct one. That said gas doesn't just leave a system, it has to leak out. Putting it back in without finding where it has been lost is a short term fix, and is not in your interests as you will be back in a month or so (or at the start of next season perhaps) to repeat the regas.

I would get a powerful torch out and examine every pipe for signs of a leak - oiliness is the commonest sign of a leak.

Interesting that this unit was supplied new on R417A looking at its dataplate.

I am back in the UK, so will pick up a few of the items you mentioned.

Thanks again for the excellent advice. I have to admit I have learned quite a bit more about the boat generally by crawling around and looking at the suggestions made on this thread.

 

[Paul_S123]

Re: Re-gas AC 417a in Spain - Causes?

Just to update, ac still not working. AC guy finally (yesterday) came up with the right gas. Just to add, on my visit in October, the working ac units per my thermometer were reducing the air temp by around 12 degrees, but the 2 saloon units were only reducing the air temp by about 2 degrees (temp dif between inlet and outlet).

So he arrived with gas, checked both units and determined they were indeed full of gas and gas was not the issue which was odd...as he previously stated it was a lack of gas (but as I was out of the country during the initial assessment and he didn't know the location of the units...it looks like that was just a guess lol)...He looks like he is full of gas lol.

Anyhow he felt it was an airflow problem and wanted to cut in stainless steel grills (one in the cockpit) which seemed odd as it would then be drawing in hot air from outside...but I told him not too as I had ran it during previously with the whole cover off in the summer and it made no difference.

He then decided it was a water flow problem, checked and bled the pump which was working fine and packed his tools and left.

The heating aspect btw seems to be working fine...it's producing a temp difference between in and out of around 10 or 11 degrees.

Any suggestions