EG4 Mini split problem

[jfharper]

My mini split got a leak, stain on concrete, oil/sticky service ports, almost no cooling. So I tried to recover the refrigerant to a recovery tank using a recovery machine but only got 142g. I was expecting more considering the unit holds 1100g total...maybe like around half.

When I first put my manifold gauge on it showed 123 PSI when the unit was off. Someone mentioned there maybe gas stuck between the 3-way valve and check valve and to run it in heat mode then cool mode with one of the service valves closed to free up the gas for recovery, but this didn't produce anymore recovery. Another mentioned see if there are jumpers to set to put the unit in recovery mode in order to pull out all the refrigerant, or get a service manual. I sent a message to EG4 via there website but have not gotten a reply...wasn't expecting to given their and SS track record.

Anyone have an idea I can try? My concern is, if after I fix the leak, N2 pressure test, vacuum down and refill weighing in the 1100g R410A, if I didn't get all the R410A out to begin with, I could overfill the system and ruin the unit.

 

[Supervstech]

My mini split got a leak, stain on concrete, oil/sticky service ports, almost no cooling. So I tried to recover the refrigerant to a recovery tank using a recovery machine but only got 142g. I was expecting more considering the unit holds 1100g total...maybe like around half.

When I first put my manifold gauge on it showed 123 PSI when the unit was off. Someone mentioned there maybe gas stuck between the 3-way valve and check valve and to run it in heat mode then cool mode with one of the service valves closed to free up the gas for recovery, but this didn't produce anymore recovery. Another mentioned see if there are jumpers to set to put the unit in recovery mode in order to pull out all the refrigerant, or get a service manual. I sent a message to EG4 via there website but have not gotten a reply...wasn't expecting to given their and SS track record.

Anyone have an idea I can try? My concern is, if after I fix the leak, N2 pressure test, vacuum down and refill weighing in the 1100g R410A, if I didn't get all the R410A out to begin with, I could overfill the system and ruin the unit.

Yeah, if you have an oil stain around the unit, you have lost nearly all the refrigerant.

125psi is meaningless. Refrigerant is a liquid and a gas, so, the pressure is just whatever the vapor point at the mean temperature of the system. If the pressure was 125, then it would need to be below 45 degrees to have liquid present… unless the system was running.

At a static temp of say 90F, a system hat is NEARLY empty, or completely full will read approximately 274psi… and could just as easily be nearly empty, as full…

Charging a minisplit requires an accurate scale, and a precise measurement of the lineset length.

He total system charge will be marked on the data plate of the unit, and a chart factor to be added for lines longer than specified will be in the installation manual.

If you pulled a recovery on the unit, and achieved a vacuum of at least 10” You are empty, and further evacuation will only serve to pull moisture and air into the system.

Pressurize the system with a minimum of 300psi of dry gas, (nitrogen, co2, helium, argon, etc…) and find the leak.
I find it helpful to close the king valves on the lineset and pressurize he sections separately, so you know if the leak is in the outdoor or indoor unit…

 

[jfharper]

Yeah, if you have an oil stain around the unit, you have lost nearly all the refrigerant.

125psi is meaningless. Refrigerant is a liquid and a gas, so, the pressure is just whatever the vapor point at the mean temperature of the system. If the pressure was 125, then it would need to be below 45 degrees to have liquid present… unless the system was running.

At a static temp of say 90F, a system hat is NEARLY empty, or completely full will read approximately 274psi… and could just as easily be nearly empty, as full…

Charging a minisplit requires an accurate scale, and a precise measurement of the lineset length.

He total system charge will be marked on the data plate of the unit, and a chart factor to be added for lines longer than specified will be in the installation manual.

If you pulled a recovery on the unit, and achieved a vacuum of at least 10” You are empty, and further evacuation will only serve to pull moisture and air into the system.

Pressurize the system with a minimum of 300psi of dry gas, (nitrogen, co2, helium, argon, etc…) and find the leak.
I find it helpful to close the king valves on the lineset and pressurize he sections separately, so you know if the leak is in the outdoor or indoor unit…

OK, thanks. Then I'll proceed with fixing the leak.

I should clarify, the stain is just under the service port and is only about 4" in diameter. If that doesn't change your advise, I'll proceed...I just didn't know if I made it seem like a stain was around the entire unit as you mentioned.

 

[jfharper]

If you pulled a recovery on the unit, and achieved a vacuum of at least 10” You are empty, and further evacuation will only serve to pull moisture and air into the system.

Had a quick question on this, since I suspected a leak I had stopped the recovery machine when my manifold gauge read about 2-3 PSI to avoid pulling in contaminants. After I find/fix the leak, then N2 pressure test individually as you advised, do you think it wise to run a recovery again to try and achieve the 10" of vacuum you mentioned (is 10" = 500 microns?), attempting to empty the system of refrigerant so I can weigh in the proper amount.

I'll be weighing in 1100g (which covers 5m of pipe stated in manual, mine is 9.8ft each pipe of line set (3/8" and 1/4"), not sure if the 5m (16ft) covers both pipes in 1 direction (20ft) or round trip (9.8ft)).

 

[Supervstech]

Had a quick question on this, since I suspected a leak I had stopped the recovery machine when my manifold gauge read about 2-3 PSI to avoid pulling in contaminants. After I find/fix the leak, then N2 pressure test individually as you advised, do you think it wise to run a recovery again to try and achieve the 10" of vacuum you mentioned (is 10" = 500 microns?), attempting to empty the system of refrigerant so I can weigh in the proper amount.

I'll be weighing in 1100g (which covers 5m of pipe stated in manual, mine is 9.8ft each pipe of line set (3/8" and 1/4"), not sure if the 5m (16ft) covers both pipes in 1 direction (20ft) or round trip (9.8ft)).

No. Recovery machines are not designed to pull a vacuum.
You will need a vacuum pump to pull a vacuum on the unit… and you should be pulling a strong, below 500microns vacuum, then pressurizing with dry nitrogen, then repeat 2 more times. It is called a triple vacuum with nitrogen purge.

After the third evacuation, the refrigerant can then be weighed in.

 

[jfharper]

No. Recovery machines are not designed to pull a vacuum.
You will need a vacuum pump to pull a vacuum on the unit… and you should be pulling a strong, below 500microns vacuum, then pressurizing with dry nitrogen, then repeat 2 more times. It is called a triple vacuum with nitrogen purge.

After the third evacuation, the refrigerant can then be weighed in.

Is it possible to do a triple evac on a mini-split with R410A? So, after leak repair, N2 pressure/bubble test, both kings open, vacuum entire system to max vacuum (evac #1). R410A upside down into service port (schrader removed) using KwikCharge to about 0 PSI. CLOSE low side king, vacuum again hoping open high king will pull R410A through...at -30mmHG open low side king and vac to max acheivable (evac #2). Repeat (last sentence) (evac #3). Is this possible or make sense to do? After which weigh in factory charge.

 

[Supervstech]

Is it possible to do a triple evac on a mini-split with R410A? So, after leak repair, N2 pressure/bubble test, both kings open, vacuum entire system to max vacuum (evac #1). R410A upside down into service port (schrader removed) using KwikCharge to about 0 PSI. CLOSE low side king, vacuum again hoping open high king will pull R410A through...at -30mmHG open low side king and vac to max acheivable (evac #2). Repeat (last sentence) (evac #3). Is this possible or make sense to do? After which weigh in factory charge.

That would be an EPA violation… intentionally venting a greenhouse gas…
Nitrogen or other dry gas not classified against venting.

 

[jfharper]

OK, Ill stick to N2

 

[prince_a]

by the way, try to add N2 and check the shredder valve core, you said the oil is on the service port, sounds to me like the shredder core is leaking out, I will check that first under N2 pressure first , get a sniffer if you can or mega bubble