daikin F3 high discharge temp

[r.bartlett]

chaps we have a system which keeps going on f3. we know the charge is correct but found that the oil return line is always red hot. we suspect the oil separator is not working correctly and acting as a hot gas injection line instead causing the high discharge temp.

attached is the picture of the unit. Can some one confirm the operation of the separator as we have an old unit being taken out soon so were going to swap the O.S out

TIA

10910

[nike123]

Is this refrigerant diagram applicable in your case?


http://hvactutorial.files.wordpress.com/2010/12/vrv-piping-diagram-cooling-cycle1.jpg?w=630&h=425

[r.bartlett]

It's the inverter compressor10911

[nike123]

Oil level in oil separator is probably controlled by float.

http://www.carly-sa.com/carlysoft/images/image/TURBOIL.jpg

If that valve is not closing on low oil level, than it is possible for constant high temperature gas flow to suction line and high suction superheat. It looks you need to change oil separator. Try to hit it hard few times with rubber hammer. Maybe that helps to unblock oil valve. Or maybe blowing nitrogen from high to low (and vice-versa) charging port.
I don't know any other possibility.

[RusBuka]

What is evap.pressure and SH in suction line. And whats the temperature of discharge pipe, DSH and condensing pressure. How quick system fall by error in full load?

p.s. lol, the second time I looked at the photo.))) nike123 was right. Try to hit oil separator) or change if its not help.

[r.bartlett]

What is evap.pressure and SH in suction line. And whats the temperature of discharge pipe, DSH and condensing pressure. How quick system fall by error in full load?

p.s. lol, the second time I looked at the photo.))) nike123 was right. Try to hit oil separator) or change if its not help.

thanks to both..


sat for 20 mins on Monday hitting OS in the hope that worked but sadly not :-/ unit is being removed in March but we are worried the high temps will take out the compressor...

[install monkey]

also solonoid e,b on rb's schematic will dump discharge gas back into the suction accumulator

[RusBuka]

Temperature rise right above oil return on suction line.

[r.bartlett]

discharge temp 80c +

[RusBuka]

whats model of outdoor unit?

80+C at full load? Whats the frequency of Inverter?
100C and higher very bad for PVE.

[r.bartlett]

whats model of outdoor unit?

80+C at full load? Whats the frequency of Inverter?
100C and higher very bad for PVE.
we have seen temps of 105c on the checker before F3 fault.

[install monkey]

best way to proove this is to pinch off the oil return pipe see if the pipe temp drops- if so,change the oil sep-if not ur gonna have to degas it to repair the oil line

Oil level in oil separator is probably controlled by float.

http://www.carly-sa.com/carlysoft/images/image/TURBOIL.jpg

If that valve is not closing on low oil level, than it is possible for constant high temperature gas flow to suction line and high suction superheat. It looks you need to change oil separator. Try to hit it hard few times with rubber hammer. Maybe that helps to unblock oil valve. Or maybe blowing nitrogen from high to low (and vice-versa) charging port.
I don't know any other possibility.

[r.bartlett]

best way to proove this is to pinch off the oil return pipe see if the pipe temp drops- if so,change the oil sep-if not ur gonna have to degas it to repair the oil line

will try that first once we get the spare OS out.:)