IOM 1210-7 • MAGNITUDE
®
MODEL WMC CHILLERS
30 www.DaikinApplied.com
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peraTIon
If the “Control Source” on the HMI MODES Setpoint Screen is
set to “Local,” press the STOP button on the HMI to disable the
chiller. This method of disabling will cause the chiller to act in a
similar manner as when it is disabled using the Unit Switch in
the “Switches” or “BAS” mode.
Economizer Control
The economizer can be activated by enabling control of the
economizer expansion valves if equipped. The economizer
expansion valve logic will optimize the performance of the
economizer while also preventing compressor interstage liquid
refrigerant carryover. The logic also manages dual compressor
operation by closing the economizer expansion valve that
feeds the inactive compressor to prevent refrigerant bypass.
The economizer will turn completely off when it is no longer
efficient to economize, or when the circuit is not in the run
state.
Machine Interface Screen
(HMI)
The following sections outline the operation of the HMI panel.
HMI On/Off
The HMI is turned on/off with a switch located at the lower
front of the display panel. Screen control buttons are located
to either side of it and elicit on-screen prompts when pressed.
The HMI is equipped with a screen saver that can be
configured to initiate at 10,30 and 60 second increments. If the
screen is black, touch it first to be sure it is on before using the
ON/OFF button.
Chiller Operation Without the HMI
The Human Machine Interface touch screen (HMI)
communicates with the controller, displaying data and
transmitting touch screen inputs to the controllers. It does
no actual controlling and the chiller can operate without it.
Should the touch screen become inoperable, no commands
are necessary for continuing unit operation. All normal inputs
and outputs will remain functional. The unit controller can be
used to view operational data, to clear alarms, and to change
setpoints, if necessary. See
section starting on
for more information.
Navigation Summary
The Home View Screen, see
, is
usually left on. This screen contains the AUTO and STOP
buttons used to start and stop the unit when in “Local” control
mode. Other groups of screens can be accessed from the
Home View Screen by pressing one of ten buttons on the
bottom of every screen:
• EVAPORATOR
• COMPRESSOR
• CONDENSER
• EXPANSION
• TOWER
• SETTINGS
• TREND
• ALARM
• OPERATOR
Additional details and screen captures can be found on pages
35-49.
Figure 23: HMI Screen Layout
VIEW Screens
View screens are used for looking at unit status and conditions.
Home View Screen
The Home View Screen (
) shows the basic operating
condition of the chiller and is the screen that is normally left
on. Note that the chiller displayed on this screen, as well as on
all other screens that display an image of the chiller, will show
either one or two compressors depending on the chiller model.
HOME
SCREEN
SETPOINTS
HOME
SCREEN
TREND
OR
ALARM
HISTORY
TIMERS
ALARMS
VALVE
TOWER
MOTOR
MODES
SET
WATER
PRESS SET
PRESS VIEW
HISTORY
PRESS HISTORY
PRESS VIEW
SET SCREENS
HOME
SCREEN
DETAIL
VIEW
SCREEN
COMPRESSOR STATE
LIFT
EVAPORATOR
CONDENSER
VIEW
PRESS VIEW
PRESS VIEW
VIEW SCREENS
HISTORY SCREENS
REFRIGERANT
EVAPORATOR
CONDENSER
INTERFACE
TOWER
EXPANSION
SETTINGS
ALARM
TREND
COMPRESSOR
OPERATOR
TOWER FAN
UNIT PARAMETERS
ECONOMIZER