Johnson Controls RC Series Engineering Manual page 21

Application Notes cont.
Water Piping
Piping is usually design as 'reverse return' to equalize flow paths
through each unit. A short flexible pressure rated hose is used to
make connection to the fixed building piping system. This hose
is typically stainless steel braid and includes a swivel fitting on
one end for easy removal and is flexible to help isolate the unit
for quieter operation . Isolation valves for servicing, y-strainers for
filtering and memory-stop flow valve or a balancing valve can be
provided for consistent water flow through the unit.
All unit source water connections are fittings that accept a male
pipe thread (MPT). Insert the connectors by hand, then tighten
the fitting with a wrench to provide a leakproof joint. The open and
closed loop piping system should include pressure/temperature
ports for serviceability. The proper water flow must be provided to
each unit whenever the unit operates. To assure proper flow, use
pressure/temperature ports to determine the flow rate. These ports
should be located at the supply and return water connections on
the unit. The proper flow rate cannot be accurately set without
measuring the water pressure drop through the refrigerant-to-
water heat exchanger. Check carefully for water leaks.
Condensate Drain
On console units, the internal condensate drain assembly consists
of a drain tube which is connected to the drain pan. A condensate
tube is inside all cabinets as a trapping loop; therefore, an
external trap is not necessary.
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RC SERIES ENGINEERING GUIDE