Specifications

6 Cat 604-5
Features and Benefits
Open Choices™ BAS Flexibility
The exclusive Open Choices feature provides seamless
integration and comprehensive monitoring, control, and two-
way data exchange using industry standard protocols
LonTalk®, BACnet™ or Modbus™. Open Choices offers
simple and inexpensive flexibility to use the Building
Automation System of your choice without an expensive
gateway panel. Open Choice Benefits include:
• Easy to integrate into your BAS of choice
• Factory- or field-installed communications module
• Integrated control logic for factory options
• Easy-to-use local user interface
• Comprehensive data exchange
Compliance with ASHRAE Std. 90.1
According to ASHRAE, chillers usually spend 99% of their
operating hours at off-design conditions and most of this time
at less than 60% of design capacity. Thus, the off-design
efficiency of chillers is all-important.
ASHRAE Standard 90.1 was developed to assist owners and
designers make informed choices on a buildings design,
systems and equipment selection. Magnitude chillers can
significantly exceed ASHRAE 90.1 minimum efficiency
requirements.
Integrated Variable Frequency Drives
A Variable Frequency Drive (VFD) modulates compressor
speed in response to load and evaporator/condenser pressure.
VFD technology significantly reduces power input at part load
operation and at lower than design ambient temperatures.
When minimum speed is reached, moveable inlet guide vanes
redirect the gas flow into the impeller.
The VFD can dramatically reduce annual energy costs when
there are long periods of part load operation and/or low
compressor lift (lower condenser water temperatures). The
attributes of VFD drives produce one of the industry's most
efficient single-compressor chillers based on the all-important
IPLV value. See IPLV/NPLV Defined inset for details on the
AHRI IPLV efficiency rating.
An additional benefit of a VFD is improved power factors that
may help reduce power costs.
The use of a VFD on centrifugal chillers also provides an
excellent method of reducing motor starting inrush-even better
than “solid state” starters. Starting current can be closely
controlled since both the frequency and voltage are regulated.
This can be an important benefit to a building's electrical
distribution system. Low inrush current at startup is also ideal
for operation with backup or emergency power systems and
can reduce the size of backup generators.
VFD Harmonic Considerations
The Institute of Electrical and Electronics Engineers (IEEE)
has developed a standard (IEEE519) that defines acceptable
limits of site specific system current and voltage distortion.
The designer may wish to consult this standard to ensure
acceptable levels of harmonic distortion are maintained. The
harmonic characteristics of the standard VFD drive (WME500
Motor Code M2) will be acceptable in the vast majority of
applications without the use of additional costly harmonic
filters or low harmonic drives.
WME Reduced Harmonic Options
The low harmonic drives (Motor Codes M3 for WME500 &
M4 for WME0700) are guaranteed to meet the IEEE519 Total
Demand Distortion limits if the Isc/IL ratio is greater than 20.*
An optional harmonic filter for the WME500 M2 VFD drive is
available as a factory mounted option or as an accessory to be
field mounting and wired. This harmonic filter is guaranteed
to meet the IEEE519 Total Demand Distortion limits.*
If there are any question about drive harmonics consult your
loca
l Daikin Sales Representative.
*
Daikin cannot take respon
sibility for electrical
system imbalances or for other harmonic distortion sources
within the chiller's electrical supply system.
Onboard Refrigerant Containment System
Pumpout systems are required on many jobs to collect and
contain the refrigerant charge when access to internal chiller
components is required for service. Magnitude condensers are
designed to hold the entire unit refrigerant charge (<90% full
IPLV/NPLV Defined
Part load performance can be presented in terms of
Integrated Part Load Value (IPLV), which is based on
AHRI standard rating conditions (listed above), or Non-
Standard Part Load Values (NPLV), which is based on
specified or job site conditions. IPLV and NPLV are based
on the following weighting equation from AHRI 550/590:
Using kW/ton, where:
A = kW/ton (or COP) at 100%
B = kW/ton (or COP) at 75%
C = kW/ton (or COP) at 50%
D = kW/ton (or COP) at 25%
Weighting
The percent of annual ton-hours of operation near the four
rated load points are as follows:
• 1% of operating ton-hours in the bin range 93~100
%
load (represented by the rating at 100% load)
• 42% of operating ton-hours in the bin range 62~92%
load (represented by the rating at 75% load)
• 45% of operating ton-hours in the bin range 37~61%
load (represented by the rating at 50% load)
• 12% of operating ton-hours in the bin range 0~36
%
load (represented by the rating at 25% load)
DCBA
IPLVorNPLV
12.0
+
45.0
+
42.0
+
01.0
1
=