Specifications

system consisting of a 15-inch VGA touch-screen
operator interface and a unit controller.
2. The touch-screen shall display the unit operating
parameters, accept setpoint changes (multi-level
password protected) and be capable of resetting
faults and alarms. The following parameters shall
be displayed on the home screen and also as trend
curves on the trend screen:
• Entering and leaving chilled and condenser water
temperatures
• Evaporator and condenser saturated refrigerant
pressures
• Percent of 100% speed (per compressor)
• % of rated load amps for entire unit
3. In addition to the trended items above, all other
important real-time operating parameters shall also
be shown on the touch-screen. These items shall
be displayed on a chiller graphic showing each
component. At a minimum, the following critical areas
must be monitored:
• Compressor actual speed, maximum speed,
percent speed
• Evaporator water in and out temperatures,
refrigerant pressure and temperature
• Condenser water in and out temperatures,
refrigerant pressure and temperature
• Liquid line temperature
• Chilled water setpoint
• Compressor and unit state and input and output
digital and analog values
4. A fault history shall be displayed using an easy to
decipher, color coded set of messages that are
date and time stamped. The alarm history shall be
downloadable from the unit’s USB port. An operating
and maintenance manual specic for the unit shall be
viewable on the screen and downloadable.
5. All setpoints shall be viewable and changeable (multi-
level password protected) on the touch screen and
include setpoint description and range of set values.
6. Automatic corrective action to reduce unnecessary
cycling shall be accomplished through preemptive
control of low evaporator or high discharge pressure
conditions to keep the unit operating through
abnormal transient conditions.
7. The chiller shall be capable of sequencing up to four
other similar chillers for WMC models. The contractor
shall furnish and wire network isolators for n-1 units.
8. The chiller shall be capable of automatic control
of: evaporator and condenser pumps (primary and
standby), up to 3 stages of cooling tower fan cycling
control and a tower modulating bypass valve or
cooling tower fan variable frequency drive.
9. [OPTIONAL] The factory mounted controller(s)
shall support operation on a BACnet
®
, Modbus
®
or
LonWorks
®
network via one of the data link / physical
layers listed below as specied by the successful
Building Automation System (BAS) supplier.
• Modbus
®
• BACnet
®
MS/TP master (Clause 9)
• BACnet
®
IP, (Annex J)
• BACnet
®
ISO 8802-3, (Ethernet)
• LonTalk
®
FTT-10A. The unit controller shall be
LonMark
®
certied.
10. The information communicated between the BAS and
the factory mounted unit controllers shall include the
reading and writing of data to allow unit monitoring,
control and alarm notication as specied in the unit
sequence of operation and the unit points list.
11. For chillers communicating over a LonMark
®
network,
the corresponding LonMark
®
eXternal Interface File
(XIF) shall be provided with the chiller submittal data.
12. All communication from the chiller unit controller
as specied in the points list shall be via standard
BACnet
®
objects. Proprietary BACnet
®
objects
shall not be allowed. BACnet
®
communications
shall conform to the BACnet
®
protocol (ANSI/
ASHRAE135-2001). A BACnet
®
Protocol
Implementation Conformance Statement (PICS) shall
be provided along with the unit submittal.
13. [OPTIONAL] The chiller shall be equipped with the
capability to restart and reach full load quickly in
the event of a power interruption. The compressor
shall be capable of restarting within 43 seconds after
power is restored and shall reach 80% load within
120 seconds. Chillers not able to restart or load within
this time frame shall include a properly sized thermal
storage tank to maintain temperature stability in the
system.
2.5. OPTIONAL ITEMS
A. The following optional items shall be furnished:
1. Open OR closed export crate
2. Pumpout unit, with or without storage vessel
3. Refrigerant monitor
4. Non-witness performance test (water only) in
accordance with procedures and to the tolerances
contained in AHRI Standard 550/590.
– OR –
Witness performance test (water only) in accordance
with procedures and to the tolerances contained in
AHRI Standard 550/590.
CAT 602-4 • MAGNITUDE
®
MODEL WMC CHILLERS 20 www.DaikinApplied.com
engIneerIng guIde speCIfICaTIons