Mammoth V-Cube - Manual (Page 28)

Appendix A: Water Cooled Condenser (WCC) Piping Installation,
Maintenance and Troubleshooting
Units have the WCC supply and return line internally
coupled (manifold) and piped to the unit exterior. The
WCC connections shall have copper IPS connections. See
the submittal drawings for size, location, flow rate, type of
fluid, pressure drop information and components included
and factory installed for the supply and return connections.
Optional Water Piping Components
The following components may or may not be included
and factory installed depending on the water conditions
and/or options selected.
1. A two-way or three-way modulating 1. head pressure
control valve may be included in the compressor or
coil compartment to maintain stable operation of the
refrigeration systems when operated on ground loop
or cooler water systems when the design inlet water
temperature is below 70ºF in the cooling mode. A re-
frigerant pressure transducer is also included and fac-
tory installed in the compressor compartment on the
compressor discharge, which will modulate the water
flow to the condenser using a 2 to 10 VDC signal to
prevent the compressor discharge pressure from fall-
ing below the compressor operating limit. The regu-
lating valve may be factory installed or shipped loose
for field installation depending on the unit configura-
tion and/or options selected
2. A flow switch on the water return or leaving side of
the condenser is factory provided and installed in the
compressor or coil compartment to monitor the pres-
ence or absence of flow, which will shut down the
compressor operation if no flow is detected.
3. A water temperature sensor on the water supply or
entering side of the condenser is factory provided
and installed in the compressor or coil compartment
to monitor the water temperature, which will shut
down/disable the compressors if the entering water
temperature drops below 70ºF. For units with wa-
terside economizer coils (WiSE), the entering water
temperature sensor shall be utilized to compare the
unit entering water temperature to the unit entering
air temperature and enable WiSE operation when ap-
plicable.
4. A waterside economizer coil (WiSE) along with dual
two-way modulating water economizer valves and a
temperature sensor shall be supplied with the unit.
The water temperature sensor is input to the DDC
control system, which determines when to divert
water to the economizer coil for energy conservation
in cooling mode.
Water Piping Components Not Included
Water piping vibration eliminators, manual or automatic
shut-off valves, pressure and temperature gauges, water
strainer, vent valves or air vents, flow measuring and
balancing valves, pressure relief valves or other safety or
control piping requirements are not available and must be
field provided and installed outside of the unit.
Recommended Piping, Components and
Installation
Recommended and required WCC water line piping and
components with a detailed functional description are out-
lined below:
1. All WCC should be connected to supply and return
piping in a two-pipe reverse return configuration. A
reverse return system is inherently self-balancing and
requires only trim balancing where multiple quanti-
ties of heat pumps with different flow and pressure
drop characteristics exist in the same loop.
2. The water line piping may be steel, copper or PVC.
Avoid dissimilar metal fittings as they may corrode.
The piping should be installed with a minimum
number of bends and elevation changes for best per-
formances. Size piping to minimize system pressure
drop.
3. Water line piping should contain:
a. Short sections of high pressure flexible hose or vi-
bration eliminators to reduce vibration and noise
transmission .One end of the hose should have
a swivel fitting to facilitate removal for service.
Hard piping connections are not recommended
due to the possibility of vibration that could dam-
age piping connections, joints or transmit noise.
Where hard piping is used unions should be
provided in the supply and return lines for service
and removal.
b. Manual shut-off valves in supply and return
water lines for isolation and service.
c. Pressure and temperature gauge connections in
the supply and return water lines to aid in start-
up and service.
d. A water strainer (16–20 mesh minimum) or some
means of removing foreign matter from the
water.
e. Manual vent valves and/or automatic air vents at
the high points of the system in the supply and
return water lines to discharge non-condensable
IMPORTANT
WCC external water supply and return piping shall be in
accordance with National and Local Codes. Line sizing,
pressure limiting devices, backflow preventers, strainers,
valves, flow temperature and pressure measuring, freeze
protection, all other safety or control piping requirements
for system operation are the sole responsibility of the
Installing Contractor and/or Design Engineer. The water
supply must be sized for the maximum flow as indicated
on the submittals.
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