In the process of fixing my flare leak (see the end of
my other thread ) my tech did something I thought was
... not necessarily impossible, but made somewhat difficult
on the newer systems. He managed to pump down my
Daikin unit and store most of the refer in the outdoor
unit, so we could at least look at the flare and make
sure it was clean and not cracked. There's nothing about
how to do this in the Daikin docs, and of course with the
inverter systems no big old-skool contactor to punch and
make the compressor run. He had me simply ask for lots
of cool at the stat, closed off the liquid valve, and then
when the lineset pressure got down to about 30-40 psig
simply pulled the disconnect and then shut the vapor line.
He said you can't go to zero because the low-press sensor
will kick and cause shutdown and a bunch of solenoids
to open up and lose the pumpdown, so you have to catch
it just at the right moment and it's not perfect. Guess where
the rest of the remaining 410a went when we went to look
at the flare...
Do y'all think this is kosher on the newer style units?
If you believe all the manuals the only way to handle
repairs is recovering the full charge first. I'm still trying
to learn where by-the-book and real life don't agree.
Oh, and this time before letting refer back out of the unit he
actually bought his pump a new bottle of oil so it would
actually pull down, implying that on that first startup we
never got anywhere near enough vacuum on the lineset
to dry it properly. I'm kind of concerned that now there
might be a bunch of moisture throughout the whole
system from that. There *are* a bunch of little filter
dryers scattered around the unit as it comes from the
factory, but why abuse them right off the line?