Specifications

3. The chiller shall be equipped with a refrigerant cooled
and integrated Variable Frequency Drive (VFD) to
automatically regulate compressor speed in response
to cooling load and the compressor pressure lift
requirement. If a condenser water-cooled VFD is
supplied, the manufacturer shall supply factory
installed dual water lters with a bypass valve and
pressure differential switch factory wired to the chiller
control panel to indicate that a lter has clogged and
requires service. The pressure differential switch
shall also provide a separate dry contact which can
be connected to the BAS system as a means of
notifying operating personnel of the need to service
the lters. If the condenser cooling circuit includes an
intermediate heat exchanger, it must be of the brush
cleanable shell and tube style. Brazed plate heat
exchangers which cannot be eld cleaned are not
acceptable. Movable inlet guide vanes and variable
compressor speed, shall provide unloading. The
chiller controls shall coordinate compressor speed
and guide vane position to optimize chiller efciency.
4. Each compressor circuit shall be equipped with a line
reactor to help protect against incoming power surges
and help reduce harmonic distortion.
5. [OPTIONAL] The chiller shall be equipped with a
factory-mounted and wired passive harmonic lter
guaranteed to meet the IEEE Standard 519 at an Isc/
IL ratio greater than 20.
B. Evaporator and Condenser:
1. The evaporator and condenser shall be separate
vessels of the shell-and-tube type, designed,
constructed, tested and stamped according to the
requirements of the ASME Code, Section VIII. The
tubes shall be individually replaceable and secured to
the intermediate supports without rolling.
2. The evaporator shall be ooded type with [0.025
in.] –OR– [0.028 in.] –OR– [0.035 in.] wall [copper]
–OR– [90/10 CuNi] tubes rolled into [carbon steel]
–OR– [ceramic-coated steel] tubesheets. The water
side shall be designed for a minimum of [150 psig]
–OR– [300 psig]. The heads shall be [carbon steel]
–OR– [epoxy-coated steel] OR [Monel-clad] –OR–
[Stainless Steel]. Water connections shall be grooved
suitable for [grooved couplings] –OR– [anged
connections]. The evaporator shall have [dished
heads with valved drain and vent connections] –
OR– [shall be equipped with marine waterboxes with
removable covers and vent and drain connections].
The evaporator shall have [right-hand] OR [left-hand]
connections when looking at the unit control panel.
3. The condenser shall have [0.025 in.] –OR– [0.028
in.] –OR– [0.035 in.] wall [copper] –OR– [90/10
CuNi] –OR– [70/30 CuNi] –OR– [stainless steel]
–OR– [titanium] tubes rolled into [carbon steel] –
OR– [Monel-clad] –OR– [stainless steel clad] –OR–
[titanium-clad] –OR– [ceramic-coated] tube sheets.
Water connections shall be [grooved suitable for
grooved couplings]—OR– [anged]. The water side
shall be designed for a minimum of [150 psig] –OR–
[300 psig]. The condenser shall have [dished heads
with valved drain and vent connections] –OR– [shall
be equipped with marine waterboxes with removable
covers and vent and drain connections]. The
condenser shall have [right-hand]
–OR– [left-hand] connections when looking at the
unit control panel.
4. An electronic expansion valve shall control refrigerant
ow to the evaporator. Fixed orice devices or oat
controls with hot gas bypass are not acceptable
because of inefcient control at low load conditions.
The liquid line shall have moisture indicating sight
glass.
5. Re-seating type spring loaded pressure relief valves
according to ASHRAE-15 safety code shall be
furnished. The evaporator shall be provided with
single or multiple valves. The condenser shall be
provided with dual relief valves equipped with a
transfer valve so one relief valve can be removed for
testing or replacement without loss of refrigerant or
removal of refrigerant from the condenser. Rupture
disks are not acceptable.
6. The evaporator, suction line, and any other
component or part of a component subject to
condensing moisture shall be insulated with UL
recognized 3/4 inch OR 1 ½ inch closed cell
insulation. All joints and seams shall be carefully
sealed to form a vapor barrier.
7. [OPTIONAL] The evaporator waterbox shall be
insulated with UL recognized 3/4 inch OR 1 ½ inch
closed cell insulation. All joints and seams shall be
carefully sealed to form a vapor barrier.
8. Provide factory-mounted and wired, thermal-
dispersion water ow switches on each vessel to
prevent unit operation with no or low water ow.
C. Vibration Isolation
1. Provide neoprene wafe-type vibration isolators for
each corner of the unit.
D. Power Connections
1. Power connection shall be single point to a factory-
mounted disconnect switch OR shall be multipoint to
each compressor power panel on two-compressor
units.
E. Chiller Control
1. The unit shall have a microprocessor-based control
www.DaikinApplied.com 19 CAT 602-4 • MAGNITUDE
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MODEL WMC CHILLERS
engIneerIng guIde speCIfICaTIons