VRV oil level

[r.bartlett]

Gents

Today we (or rather ''they'') suffered a pipe failure of the oil balance line between two compressors on an old K-Plus VRV

Now we have no real way of knowing exactly how much oil has been lost.Don't mind the orange effect one previous maintenance company were addicted to UV dye!

What should we do past from adding new oil with the old "one Mississippi, two Mississippi, three Mississippi" method?

Plus:

Can anyone confrim which oil is suitable for an old Daikin R22 VRV system?

[install monkey]

daikin do an oil kit-where u suck the oil from both compressors and refill with sunisol-daikin would have to advise of the ammount.costs about 150 quid with oil.and u get a tin can some hose and some japanese playdoh!!

[DTLarca]

Gents

Today we (or rather ''they'') suffered a pipe failure of the oil balance line between two compressors on an old K-Plus VRV

Now we have no real way of knowing exactly how much oil has been lost.Don't mind the orange effect one previous maintenance company were addicted to UV dye!

What should we do past from adding new oil with the old "one Mississippi, two Mississippi, three Mississippi" method?

Plus:

Can anyone confrim which oil is suitable for an old Daikin R22 VRV system?

After full load operation or better an oil harvest cycle you could join two hoses with a sight-glass then connect one end to the lowest point in the shared oil circuit (add shrader if necessary) and the other to the highest point in the coil circuit (shrader at compressor suction). Then ask how the seen level compares to preferences.

[puddleboy3]

I would drain any remaining oil in the compressors on all the outdoor units, check the manual and compare to the amount drained. Its anybody's guess as to how much is in the pipework but, I would re-charge as per the manual and replace the equalising line between all compressors with a flexi refrigerant line to prevent further problems. With previous contractors adding UV dye you can imagine there has been a few refrigerant leaks on the system and you can put money on that they have not always topped up the oil after every leak. K series VRV plus must be R22 approx ten year old! Time to change the outdoor units over to the VRV Q units.

[VRVIII]

Gents

Today we (or rather ''they'') suffered a pipe failure of the oil balance line between two compressors on an old K-Plus VRV

Now we have no real way of knowing exactly how much oil has been lost.Don't mind the orange effect one previous maintenance company were addicted to UV dye!

What should we do past from adding new oil with the old "one Mississippi, two Mississippi, three Mississippi" method?

Plus:

Can anyone confrim which oil is suitable for an old Daikin R22 VRV system?

Hi Mr.Bartlett,

After closely inspecting your attached photo I would say you require 2.47L in total :D

Why not just drain the oil from module with fractured oil line and refill as per below details.


Inverter modules

RXY8K7W1
Inv comp = 2.7L
Std Comp = 2.6L

RXY10K7W1
Inv comp = 2.7L
Std Comp = 2.9L

Standard Modules

RNY8K7W1
Std comp 1 = 2.9L
Std comp 2 = 2.9L

RNY10K7W1
Std comp 1 = 2.9L
Std comp 2 = 3.3L

The oil specified by Daikin is Suniso 4GSDID-K
P.S. The UV dye will cause EEV’s problems:eek:

[puddleboy3]

Hi Mr.Bartlett,

After closely inspecting your attached photo I would say you require 2.47L in total :D

Why not just drain the oil from module with fractured oil line and refill as per below details.


Inverter modules

RXY8K7W1
Inv comp = 2.7L
Std Comp = 2.6L

RXY10K7W1
Inv comp = 2.7L
Std Comp = 2.9L

Standard Modules

RNY8K7W1
Std comp 1 = 2.9L
Std comp 2 = 2.9L

RNY10K7W1
Std comp 1 = 2.9L
Std comp 2 = 3.3L

The oil specified by Daikin is Suniso 4GSDID-K
P.S. The UV dye will cause EEV’s problems:eek:

So how do you tell how much oil is left in the other modules?

[r.bartlett]

I would drain any remaining oil in the compressors on all the outdoor units, check the manual and compare to the amount drained. Its anybody's guess as to how much is in the pipework but, I would re-charge as per the manual and replace the equalising line between all compressors with a flexi refrigerant line to prevent further problems. With previous contractors adding UV dye you can imagine there has been a few refrigerant leaks on the system and you can put money on that they have not always topped up the oil after every leak. K series VRV plus must be R22 approx ten year old! Time to change the outdoor units over to the VRV Q units.

This system has had a mninimum of 10 compressors over it's life (see below) so there has been additional oil added with each new compressor..

As regards changing, this road has been travelled several times and the Q was investigated and rejected. Part of this investigation revealed this (+ 4 other K-Plus systems) were incorrectly installed way outside design parameters. So much so that the install now subject to an impending court case under UK latent defect laws.

[r.bartlett]

So how do you tell how much oil is left in the other modules?

Or in the pipework? or would you add the total from the compressors and 'assume' the rest is in the pipe? (although there is still the unknown amount on the floor to be included...)

Can you have 'too much' oil and if so how much is too much??

[DTLarca]

Or in the pipework? or would you add the total from the compressors and 'assume' the rest is in the pipe? (although there is still the unknown amount on the floor to be included...)

Can you have 'too much' oil and if so how much is too much??

If the installation manual does not request any oil be added after first start-up in the same way that it asks for a refrigerant top-up based on piping dimensions and lengths then the permissible oil level fluctuation in the compressors will be quite broad.

If the piping is already oil charged from years of operation plus years of additional oil added with additional compressors then simply draining the compressors to recharge them with a volume equivalent to the original factory charge would be something of a risk.

I would use the sight-glass and two-hose level-indication method after both a fully loaded run and the 1hr-after-start-up oil harvest cycle.

[VRVIII]

So how do you tell how much oil is left in the other modules?

After the oil line fractured it wouldn’t take long to loose the oil and refrigerant charge, this in turn would trip the system on low pressure or high discharge temp. Why would you think this would affect the oil level in the other modules?

These systems do not have an independent oil equalising line between the units, oil equalisation between modules is activated based on time and number of operating modules, the oil level is not taken into account (2hr operation with only 2 modules operating).
The oil return function takes place every 8hrs, however If an oil return was activated after the oil line fractured, the refrigerant shortage would result in lower suction pressure and reduced velocity to bring the oil back.

I would be far more likely to have a large quantity of oil within the field piping/indoors especially when considering the system has exceptionally long pipe run lengths.

[puddleboy3]

After the oil line fractured it wouldn’t take long to loose the oil and refrigerant charge, this in turn would trip the system on low pressure or high discharge temp. Why would you think this would affect the oil level in the other modules?

These systems do not have an independent oil equalising line between the units, oil equalisation between modules is activated based on time and number of operating modules, the oil level is not taken into account (2hr operation with only 2 modules operating).
The oil return function takes place every 8hrs, however If an oil return was activated after the oil line fractured, the refrigerant shortage would result in lower suction pressure and reduced velocity to bring the oil back.

I would be far more likely to have a large quantity of oil within the field piping/indoors especially when considering the system has exceptionally long pipe run lengths.

My question still stands how do you know how much oil is left in the other modules?I don't think the customer would be happy with an if and but answer. Your explanation of the oil equalising and oil return mode's are spot on but we all know that if you have a refrigerant leak there is no sure way of calculating the oil left in the system. As in the previous posts the sight glass idea is probably the best way to guage it. Maybe Mr Bartlet can update us on the outcome?

[r.bartlett]

Well we were in a quandary. Not helped by the fact that the system HAD to be up and running by midday yesterday. What we did know was that the balance pipe flare failed catastrophically and blew off at the L/H compressor oil connection.
the force of the refrigerant would have emptied both compressors of oil in that module.

Draining out the remaining oil from the others would not have proved much as we have no idea of where the system was in relation to it's oil harvest cycle.
Plus this system is over piped by some 60M (first refnet to last indoor 100m+) and with the condensers being on the 4th floor roof and pipes snaking along the building to the 1st calculating the total amount of oil would be impossible.

Whatever, the compressors need oil to run. we decided to add 4L of oil to the module and let it run till we can get back during a quieter spell to take stock. Till then, I am led to believe these compressors have a line from the sump to the top to remove any overfill directly into the discharge pipe. thus we should be reasonably protected.