AC 4 Ton Rudd Slow Leak..somewhere..

Athana

Hi..I have two 4 Ton Rudd Units in New Jersey but since installed 10 years ago we usually only used the one which covers the part of house we inhabit which actually is enough on most summer days even for the other areas except for the hottest days.
It took a while before I realized that the Unit we don't use doesn't cool cause we didn't use it.
So this year we got a guy who checked the Freon and it was low..he filled it..was cool for a couple of weeks then decreased..he came back 3-4 weeks later it was low. He took refrigerant out put high pressure on Condenser..and began checking carefully for leaks up at the unit in attic and connections with soap and water manner (he doesn't have that electronic leak detector thing) he went to lunch came back an hour later and there was no drop in pressure in the Condenser. So..he can't find leak next step check the lines going up out side of house within insulation inside a piece of gutter.
Being that Condenser seemed good and unit in attic seems good..and for the 10 years are just about unused I told him maybe best to change the lines.
So he changed the lines and my wife was with him handing him stuff he needed etc and she says he looks like a perfectionist doing the install. He cleaned Condensor which was very dirty oddly since we never used it and recharged unit. This time hardly cooled..the last time it was cool for quite a while this time little to nothing but somehow must be doing something as it is dripping water out of that drain line.
What can it be..could the leak be within a part that opens up during operation thus doesn't show up in pressure test ?? : (
What now ?
Thanks

HVACNUT

Did he section everything into 3 parts for the test? Evaporator, condenser, and line set?
Sectioning and charging each to minimum 450 psi nitrogen should show the source. We will do this and go back 2 or 3 days later to check pressures. 
Once the leak, or leaks are repaired, a triple vacuum to 500 microns is performed. You didn't mention that and is the only way to know the refrigerant circuit is free of non condensables. 
While putting everything back together, the liquid line drier should be replaced as well. 

EBEBRATT-Ed

What @HVACNUT said.

Usually we test with an electronic leak detector because it saves time. Pressurizing with Nitrogen is a 100% sure test letting it sit overnight.

Of the 3 place to have a leak it is usually in the condenser or evaporator, the line set is usually less of a problem but a leak can be anywhere

Athana

These two recommendations are very very appreciated and was about to call him to say lets do it
as you guys suggested..but my wife then notices that though the attic unit is running..with no cooling as we never shut it off for 4-5 days (but it was getting humidity out as drain was dripping water outside) the Fan of the Condenser outside is not working ?? I looked drain not dripping water..
So another step back.
There is power to the Condenser but but is not running..he changes a soda can looking thing with two connections on top..(I forgot what its called) still not working. He doesn't know..
Im guessing the fan motor from not shutting for 4 days maybe burned out ? So what ever it is has to be fixed before we get back to finding leak.. : (

mattmia2

The thing in the can is a capacitor for one or both motors. It is pretty easy to check for the common ways a motor fails with an ohmmeter.

If it has a low pressure switch and the pressure is low it won't turn on the compressor or fan until there is a minimum charge in it to keep the pressure up.

Athana

My wife says that he told her..he speaks Portuguese..
that a Fuse was blown and that the Motor works but the Fan is not moving ?
He doesn't know why ? He wants to replace the Fan..
She told him wait..that she wants to ask the Forum..
so Im asking please Help.. : (

EBEBRATT-Ed

@Athana

Sorry to say you need a new technician. This isn't rocket science. Finding and fixing leaks can be a challenge. but

Motor problems and weather the unit runs or not is pretty straight forward. If he can't figure that out you need someone else

Athana

"If it has a low pressure switch and the pressure is low it won't turn on the compressor or fan until there is a minimum charge in it to keep the pressure up."

Is it possible this Low Pressure Switch is why fan is not running ?

EBEBRATT-Ed

@Athana

It's possible but most units don't have a low pressure switch.