LG heat pump condensor fans slow running

[Mickvee]

Has anyone come across a problem with the condensor fans running slow, then speeding up momentary then slow again. The unit overheats and the compressor shuts down. I was told this could be due to lack of refrigerant, as the unit has a thermostat which checks the condensor temp.

[Abe]

Mickvee

Is this a 407C system. I think I had a similar problem last year . It was glide related. Please offer further details.

[Mickvee]

The unit uses R22 ,model LT-B3660HL, looking at the condensor clean condition it seems the fan have not run at full speed for a long time. There is a identical unit next to it which fan run full speed.

[frank]

This sounds like a sensor problem.

Why don't you swap the sensors, pcb etc with the good one to eliminate the faulty part.

[chemi-cool]

Well, you know,the temp differences between day and night in the UK are "so" large that it makes me wonder why on earth do you need the fan speed control.

Just connect the fan to the compressor AC supply and I can assure you that it will work just fine, Summer and winter.

You have to understand the reason for the fan speed control,

it need to keep the evaporating temp, more or less constant.
if the out door temp doe's not change much, so is the evaporator temp and so, the fan should run in a more or less the same speed.

Another thing to bear in mind, is the competition between the manufacturers about the amount of useless gimmicks that a mini split > vrv can do.

Can i get a cup of Turkish coffee out of a mini split? That will be the day

Chemi

[Mickvee]

Thanks for the help, I was planning to wire them to run full time at full speed, but I was not sure of the reason for the twin speed. I was told by LG that lack of refrigerant can cause this problem ?

[chillin out]

I would reclaim all the gas and vac and recharge.
It could be overcharged.

[Servicefrigo]

Yes!
Recharge it ,you will make some money in +.(Dont you want that?),and the units will go much better.The customer also will be much satisfy.

[chilly]

Im just worried about sending something outside its manufacturers design, There may be good reason for the thing to have fan speed control and i would keep pluging at the problem.
Probably more out of stubborness than anything else. But for instance if the system is cooling a comms room we definatly need the fan speed control for winter cooling. Other wise you will freeze the coil.

If the system is a heat pump:
In the warmer wether if the unit is set to heating at a high temp but the indoor fan speed is set on a low setting the unit needs to ba able to slow down the outdoor fan speen to decrease the amount of heat being sucked into the system and hence decrease head pressure, With the fan speed control wired out the compressor can overheat.

If it is a cooling only unit and is not going to be used bellow a ambiant of 17 degrees, then i totaly agree the fan speed is not needed.
But if other i would not leave the system without fan speed control. Sorry to be abit pedantic

[sean1]

Why Not Wire Fan Into The Compressor. If The System Operates Ok Then You Know It The Condenser Sensor.it Will Save You Changing All Parts And Take Five Minutes.

[frank]

Other wise you will freeze the coil.

Only true if using a cap tube.

[marco70]

l hadthe same problem and found the cap was blown on one side because it has two caps in one

[esmailji]

its very easy for sensor to fall out from its copper pocket located 3/4 way down on condenser near the pipe entry of unit. this normaly happens on installation when your interlink cables or pipework hits it.