high humidity need advice

[Guest 18340]

Is the unit showing any "fault codes"?
Theirs a few little green lights on the lower right side of the indoor unit. Are any of them blinking? Or blinking when you change the temp with the remote?

 

[Yes4Prop215]

i run a 165 pint santa fe dehuey for my 10x10 room.....it does raise temps by a few degrees so on hot days i turn her off....but for the most part my room is around 47% humidity.....and at night she doubles as a heater because she keeps the night temps pretty stable and warm...

did you try aircooling the lights to bring temps down? 10x10 temps raise up pretty fast thats why i rock a 10in exhaust that clears the air pretty quick....on hot days i dim my ballasts and even turn a light or two off...


and if you have a res in the room keep a lid on it..

 

[black_thumb]

there are no blinking lights. would there be one if it where low on freon or if the expansion valve was blocked?

the condenser will run for 5 mins and shut off for 5 mins. when the small line gets ice on it that's when the condenser stops running.

does any know what the pressure for the low and high service ports should be?

 

[Guest 18340]

Off hand I don't know what the pressures should be but do a thorough google search and you'll find it.
No, it won't throw a fault code for low freon, but may for a faulty expansion valve. Not 100% sure on that.
Let me do some research for ya...See if I can find the service manual.

 

[eyes]

Hey black thumb, heres some stuff i found-


I work with Mr Slim day in and day out, having been trained and approved by Mitsubishi.

P8 could mean 2 different things, depending on the control system in use. There are 2 types, A and K. The easiest way to decide in on the gas. If it's on R22, then you have a K control, if it's R410A (I don't know if you use R407C) then it's an A control. The very last letter on the model number will be either A or K.

If it's a K control P8 means that there is an outdoor unit malfunction
If it's an A control P8 means that there's an abnormality in pipe temperature.

P6 means that the coil on the indoor unit is running either too cold-less than -15 F or over 70F. In cooling mode, which I assume is the case at this time of year it will possibly be icing up. Most common cause is dirty filters, or if not then check suction pressure and convert to evaporating temp on your gages. It may be a loss of freon due to a leak. If you want the codes, give me an e-mail address and I'll e-mail them to you. Let me know how you get on. I'd be happy to guide you through if you give me an idea of symptoms.

The 2 fault codes you are getting are related to each other. The P6 code is generated because of a freezing or overheat protection in the pipe or on the evaporator or condenser coil. If the temerature is abnormal as detected by the thermistor, the unit will shut down to protect itself. The causes of this could be a number of things. The most obvious would be bad airflow-I don't think from what you say that the filters would be blocked, if the fan on the indoor ubit is not running properly, the same effect would be had. Make certain that the fan on the outdoor ubit is operating correctly(although this would really only affect the system in heating mode if it is a heat pump). The frosting back on the discharge line could be a result of an overcharge of refrigerant, or a restriction in the liquid line as well as a problem with the reversing valve if fitted-so check that as well to make sure it is operating OK. What I would do is to follow the frosting on the liquid line to see how far back it goes and whether it leads to a blockage somewhere. This will be easy to spot as if there is a blockage, there would be a quite large temperature difference in the line across it. I notice that the unit has been moved to another office. If this office is smaller or has a much lower heat load than the area where the unit was previously installed the fault codes would be generated, due to either the operation at a temperature lower than the units tolerance range, or short cycling of air.
P8 code is generated because of an abnormality in the pipe temperature, the frost on the line would explain why you have this code, as the pipe temperature must be within a set range(which is the lower temperature between the evaporator temp and the liquid line temp-intake temperature-the thermistor needs to detect a temperature within 3 degrees C of this range, but thats not really important). It takes a minimum of 9 minutes to detect the fault Causes could be either a disconnected thermistor, or a shortage of refrigerant, defective reversing valve or even a piping fault (quite rare)make sure the maximum pipe run is not exceeded. Have you checked the liquid line temp where it leaves the condenser?.
There are numerous explanations and if you could give me air temps and suction pressures for this I could probably help yu to pinpoint the exact cause, but from what you have said already it is strange that the problem only occurs once the unit is moved so I suspect there is either a large reduction in cooling load, or perhaps the space to be air conditioned is much smaller causing the unit to short cycle cooled air back over the coil, giving the characteristics of an overcharged unit (assuming that the charge is completely correct)
Sorry for such a long winded reply, but if you could give me a bit more info, then I'm certain we would be able to nail it.