Carrier Packaged air conditioning unit circa 1950.
Open belt drive 5FD and one converted to 06D
View of Carrier water cooled packaged system circa 1950.
This system has been converted from R500 (Careen 7) to R22, by changing
the expansion valves and increasing the pulley size on the open belt drive
compressor to slow it down to accommodate the heavier R22.
The big cast iron pipe is a steam line for the heating
Front view of the system Carrier 5FD open belt drive
(left) and new Carrier 06D (right). Notice the two new oil pressure safety
controls added when the 06D was installed. Previous systems did not have
oil safeties and compressors would only last a few seasons. Notice the
great big suction line filter dryer in the liquid line. This system only
had a set of screen strainers (top image round objects near the expansion
valves), not very good for removing pieces of torn up compressor from years
Rear view of 06D compressor (left) and open belt drive
5F (right). Notice the crankcase heaters installed in both compressors
(the open belt drive unit has an immersion well). Previous compressors
didn't have heaters and would only last a few seasons (amazing that they
lasted that long). If these units had oil safety controls the system would
not run without tripping on low oil pressure, instead they just tore up
compressor after compressor.
May 1st 2001. After problems of the system
going off on "high head pressure" we convinced the owner to have us clean
the water cooled condensers. This was done by removing the heads on each
end on the tubes and running a brush through the tubes with a power drill.
There are 8 groups of 4 tubes each for a total of 32 per condenser. This
was a major job but paid off because we were able to remove years of calcium
build up. The final step is to run hydrochloric acid through the system
to remove the rest of the calcium carbonate (CaCo3).
In the process of cleaning we discovered
that the swimming pool pump that is used to move the water through the
condensers is connected backwards. Instead of the water being pushed
through the system it is arranged so the weight of the water from the cooling
tower on the roof is pushing the water through the condensers instead the
the pump doing the work.
Written By: Scott Meenen
N3SJH of: G&S MECHANICAL SERVICES. Specializing in Mechanical, Controls
and Electrical Modifications Of
Heating, Air conditioning, Refrigeration,
Ice Production and Food preservation.
Anything having to do with Heat and Energy.
Serving MD, DC, and Northern
VA. Contact us by pager: 1-877-467-2914 Page
us by e-mail firstname.lastname@example.org 240Chrs max.