Techumseh, direct suction compressor
Rick Allgeier
Does anyone know about the Tecu. Direct suction compressors. I have
seem as many as 4 replacements in one unit. These seem to be very
suceptable to damage during low load conditions. The compressors in
question are in Carrier 20 ton rtu and Lennox 20 ton rtu. They are ten
ton compressors. I know that Lennox has since changed the replacemenbt
to a different compressor with a re-pipe kit and suction filter drier.
I should think that any compressor that is a direct suction design(the
returning gas goes directly to the valves) should have an accumulator
installed. Can anyone give me information on this compressor or share
your experiences with this problem.
Thanks, Rick
John Tan
Hello Rick...
My guess is that you are referring to Tecumseh SFA5612 quadroflex
compressors
which seems to replace the AN5612 (obsolete) reciprocating type
compressors.
We seldom have problems with the AN series when accumulators were not
installed
though we are aware of danger of possible floodback.
However, I did previously posted similar question before about the SFA
series of compressors.
My feedback is that due to the different internal construction of the
pistons
of the SFA series, floodback prevention is more critical during
replacement.
Beside, the instruction from Tecumseh is that a suction accumulator is
necessary
despite some OEM equipments I saw did not have one installed.
IMO, where space allows in the condensing unit, an accumulator installed
will be
necessary.
Regards,
John Tan
Al
Its spelled "TECUMSEH", Mi., its also my home town and the world
headquarters of the Tecumseh Products Company of small engine and
compressor fame.
Just some history.
Best Wishes
Al
John Tan
Hi Al...
I know, and there is also a Tecumseh University, Tecumseh Library(I
think),
somebody who is(or was) famous with name of Tecumseh.
Well, the Tecumseh famous brand name has spread worldwide including Asia
Pacific.
So, are we deviating from the subject.... :-)
Regards,
John Tan
CGN36
I have experienced the same problems on both Lennox and Carrier units,
replaced 6 of 8 compressors on a Lennox installation within 4 months of
startup. This was about 2 1/2 years ago, replacements had design change which
shifted discharge pipe height. Carrier units use a different compressor for
each of the 2 stages; replacement involves installing discharge check valves on
both compressor circuits (even though you are likely changing only one
compressor), and insulating the freeze protection switch on the first stage
evaporator. Your point about an accumulator is well taken; probably 90 % of
first time failures on the Carriers are first stage compressors. The
economizers used are notoriously crappy, mixed air runs about 66F, 1st stage
mechanical fires up with both condenser fans running .
Rick Allgeier
Has Tecumseh (for those concerned, please note that I spelled it
correctly this time) Carrier or Lennox acknoleged this problem. I,ve
talked to the local Carrier Tech Rep and have not received any decisive
information, short of that the charge is critical and do not try to
flash liquid into the suc line service port under any circumstances.
However it has been over 1 year since I last replaced a tec. compressor
in a Carrier unit. Lennox merely shiped me a normal Recip tin can with
the repipe kit and filter drier.
John Tan
Hi...
Just want to make sure, are you referring to the Tecumseh quadroflex
type of
compressor rather than the Tecumseh reciprocating or scroll compressor.
I share the same experience and I had just spoken to the Asia
representative(I'm in
Asia) today.I asked if the quadroflex compressor more sensitive to
floodback situation
than the reciprocating type.
However, their indirect reply was something like "it is not necessary to
install an accumulator but it will be better to install one" (which
doesn't make sense to me what they are talking about).
So to safeguard myself, I normally recommend the tech to install an
acummulator if they are replacing with the quadroflex compressor. (note,
in our country, replacement compressors are generally not warranted for
defect.)
Regards,
John Tan
Rick Allgeier
part of the oem rtu.
John Tan
Hi Rick..
> I,m not familiar with the name "Quadroflex" but these compressors were
> part of the oem rtu.
View http://members.tripod.com/~teckhoe/index.html
Note that I am not advertising anything, just to show you the pics.
since I
can't pose them here since this is non-binary NG.
It's not scroll or rotary, more compact than the conventional
reciprocating compressor.
Supposed to be able to digest liquid and accordingly use for
airconditioning and
heat-pump.
Any comments...
Regards,
John Tan