Post edited 3:13 pm – August 28, 2010 by Steve Pooler

Pascal said:

i was there for angela when the tech came.

he replaced the control board as a precaution to troubleshoot a separate issue...What was the seperate issue ?
when he tried to start the system, it woudn't start at all and he coudlnt' get any reading on the suction side, pressure was high on the other.…That's not really possible unless it was running (was the board the separate issue ?)

If he could get no reading on the suction side with the system off, he either did not have his hose connected correctly, he didn't have the service valve stem in the proper position, or there is a blockage in the refrigerant system as I mentioned earlier.

he cleaned the coil, which wasn't really necessary needed since it had been done recently and they turned out to be pretty clean anyway…Are we talking about the water coil, or the new evaporator coil/s they put in ?

after the cleaning, he got it running and actaully had to add gas to the system. He had it running fine with pressures at 60 and 250. water temp is around 85 to 90 deg here in teh marina, air temp inside when started was in the 90s. it was working fine,…That's not working fine at those pressures with those temps…That 60 psi suction is about 2-3 degrees from icing the evaps, thus blocking the air flow…When the cabin temp comes down just a bit, so will that suction pressure, then the system will ice…This may be why he overcharged it before…to keep the suction above 58 psi (32 degrees)…OR…It could be that DeWayne's new air handler/s (did he do 2 on that system, or just one ?) don't match well which is causing the low suction, then when icing up, the evaps pick up less heat thus allowing the cold flood back to the compressor as you were experiencing…

Anyway…With a room temp, to warm compressor (as we have already discussed)…The cabin at 90 & seawater the same temp…Pressures should be somewhere between 85-90 psi on the low side & up close or over 300 psi on the High side…As the cabin temp lowers, so will those pressures…But you can see from my pressures…He didn't give you much room….The cabin needs to lower at least 15 degrees to say 75 for comfort…but the suction can only drop a few degrees/psi before the system starts icing…We turned it off a couple of times and it restarted fine after a couple of minutes, I looked at the amp during the restart, it jumped up to abut 60 for a very brief time which is normal. voltage never dropped.

i cant' say that i understand how the mostly uneeded acid cleaned solved the issue…I can't either & I'm sure it didn't solve the issue as described to me earlier…

one question for you though… any time i've had issues with dirty coil or a complete water pump failure/blockage, the compressor woudl run for a short time before the high pressure switch woudl cut off. at least 10 or 15 seconds i believe…Yes, on first start with no flow it will take some time for the water (what there is) in the coil, and the coil to warm enough…subsequent re-starts will trip the switch sooner because the coil is now already warm…can it trip the high pressure switch instantly?…No…The switch would have had to fail in the open position for the control to instantly see Hi Ps…if that was the case, why wouldnt' the controller show an HPF error? controler brand is aqua air, with blue digital readouts and lights...That could depend on if the installer wired the high pressure switch to the control, or if he just left the original line voltage protection intact…

If it is wired to the control…I'm not sure about the Saphire control they are using, but Crusair's SMX will allow 4 tries before showing Hi/Ps…this can allow water time to get there from the pump on long runs, or allow a bag to float away from the intake with no pump suction since the pump cycles with the compressor…

it works, which is the good news, but i hate not understanding when teh exact issue was, and teh tech wasn't' sure he could explain it either.…If the tech can't explain it…He doesn't know it himself…

I would say that…There is something he dosen't know (Likely) or something he's not telling (could be both) and he had to justify his time so he changed a board & washed a coil….

I can say from the pressures you quoted at those temps…He didn't fix the Real issue…By the Way…What is the compressor temp when running now ???

To be honest…I still wouldn't recommend running that system…

Not until you can get an "experienced" non biased tech out to find out what the actual problem is…

And it could be as simple as the guy you had really does not know how to charge a system…much less one with two evaporators…

I know I said to give DeWayne a chance…But he sent a guy that obviously dosen't know what the problem is (or knows but is not telling)

Did the guy call DeWayne for guidance while he was there ?

I would want to know & get it right…With A/C…Just because it cools does not mean it will not self destruct….

Gee Honey…It was working just fine yesterday…

Steve~ 

Thanks for the complete description Ang…That really helps….I also think you should be fine with that setup…

We know you are running low suction pressure from Pascal's report…What likely happened back in June with the fan…

Ice built up inside the coil & got up against the squirrel cage, which stopped the motor, the motor then overheated & tripped it's internal overload which is auto reset…That's why they found nothing wrong back at the factory…The ice had melted & the overload had reset itself.

At Re-install the tech overcharged the system to try to get the low pressure higher & prevent icing…60 psi is not where you want it with a hot cabin…I would expect that 60 psi pressure when the cabin is down around 68 or 70 degrees…but not at 90 degrees as Pascal noted when he was there…As I have said before…With refrigerants…Pressure & Temperature Correspond…So lower cabin temp means lower pressure.

97 degrees is OK for your compressor…Not too hot (low freon) and not slugging liquid (cold compressor)

As to why one would ice without the other…Couple of possibilities…

One is not picking up it's designed amount of heat due to improper refrigerant flow thru the coil (capillary tube partially blocked, or too small)

Or the easier answer/fix would be it's leaking it's own cold air discharge back into it's own return, making it think the room is colder than it is as there is little heat in that air to pick up….

You can check for the second problem yourself just by feeling for cold air at the units return (at the coil)

Either problem should be Aqua Air's warranty since they supplied & installed the air handlers… 

BTW…The only real difference between Split systems & Self Contained units is the copper tubing in-between the air handler & the condensing unit…They can have all the same problems (except at least the factory is matching the coil to the compressor)

Steve~

Post edited 10:56 am – August 31, 2010 by Steve Pooler

Angela said:

"What likely happened back in June with the fan…Ice built up inside the coil & got up against the squirrel cage, which stopped the motor, the motor then overheated & tripped it's internal overload which is auto reset…That's why they found nothing wrong back at the factory…The ice had melted & the overload had reset itself."

Maybe, but maybe not…I let that unit sit for a whole day, off, and tried to start it the next day, in "fan only" mode. It would not turn, but the motor hummed – it was stil hung up on something. Of note, about three weeks prior to that, the unit had begun "ticking" that increased in tempo when the fan speed increased. They said it was nothing and not to worry about it. Well, it was very annoying, at a minimum! Then came the burning smell and smoke – the smell was that of an empty skillet sitting on a stove eye that was on high, or a hot griddle – definitely "very hot metal" smell. Anyway, at the time of the blower incident, I did not check for ice; the squirrel cage would not turn, but the motor hummed. I shut it down. The factory came and got it. While the unit was out, I tried to turn the squirrel cage by hand. It turned, but was stiff. On my old stuff, when you flick it with your finger, it spins for a while after that. This unit wouldn't even go a full revolution on its own.…Gosh Ang…Now again you're not being quite fair…Had I had that info about the hard to turn motor I wouldn't have wasted my typing skills (which suck) going where I did with the ice & squirrel cage thing…Someone else is not being honest if they told you nothing was wrong…Remember…There is nothing in this for me, and all I'm trying to do is help here…Having ALL the Info, does help me help. 

A week after the reinstall, the blower hung up again and that burning smell came back. The ticking was gone by then, by the way. That time, I did check for ice – NONE. I got the blower moving again by pushing the fan speed to high. The day after that is when they replaced the Sapphire control box. So far, the fan has not hung up since. No one can explain it. So, I'm not sure that ice was the culprit. I just don't know.…So my GUESS IS they must have replaced the motor and didn't want you to know….However, The ticking was likely ice touching the squirrel cage..It can come & go with the compressor cycling on the T-stat…The longer the compressor runs, the better the chance it is there…Then when the compressor cycles off it melts…

"You can check for the second problem yourself just by feeling for cold air at the units return (at the coil)"

I did that yesterday. The air coming back into coils was not cold. In fact, because I didn't feel much cold at all with my hand on the "fins", I touched the sides where the coils loop to make sure they were cold. They were cold and sweating like they should be. The air output is nice and cold. In fact, the room gets so cool that I usually leave the thermostat on 81°, otherwise it does get a little chilly in there.…STILL…."You Cannot Change the Laws of Physics Jim" (Scottie to Capt Kirk)…The suction pressures you have are going to cause ice up…It's not a questionable debate…It's FACT….

"BTW…The only real difference between Split systems & Self Contained units is the copper tubing in-between the air handler & the condensing unit…They can have all the same problems (except at least the factory is matching the coil to the compressor)" Yeah, but there are fewer places for leaks to sprout, Not really (a split system may have 4 to 6 more flare joints, and up to 4 of those can be cut out & soldered back together)…but there are many more places for barnacles to grow in the long seawater runs to & from the remote locations of SC units…and I understand they come already properly charged.…They do, but after 30 years ???…I'm thinking I don't see many 30 year old self contained units…Most are done well before that…Well, that's how I understand it anyway. And that awful modulating system I have in the lower level – there are countless flaws and potential failure points all through that system. Even the guys at Hatteras (and the guys who were there she she was built are still around!) admit that that wasn't Hatteras's greatest idea. They often tell me "it worked better on paper than it did in the field." I have to agree.

I can agree…And agree to disagree…The people that designed & developed that system are no longer around…(Jere Crews is no longer with the company & his main engineer on that system John Cox, passed a few years back) Wait a minute…Hatteras didn't have much to do with it and at that time the system had only been installed on…What 13 boats ???

Hatteras also made mistakes in a/c choices by using…actually specifying…Bi-Metal Honeywell cabin controls that couldn't keep a setpoint within 5-6 degrees of where it was set…But they installed many many more of those than just on the Modulating systems….

The Modulating system is not the subject of this thread & I'm not going to take it there now…I will in another thread if wanted though because I still am one of the few guys that knew the original designer's & believers of that system…It worked well when setup properly, and like any system, the leaks were fixed…Thing was there were not many guys that saw enough of them to know how to make them perform as they should….

It's like if you only ever saw one of anything…And didn't understand it…Well unless you stuck with it enough to get to know it…It's shit ???

Steve~

All info is important Ang…Don't forget I'm not there to see, feel, or read a thing, and my crystal ball can only see so much 

A blower/airflow problem can directly affect Compressor floodback and my answers/questions about it.

Make sure you get some pressure readings yourself before he disconnects his gauges & leaves..

Let us know how it goes…

Steve~