Daikin MAGNITUDE WME-D, Установка, эксплуатация и обслуживание, Страница: 37 / 56

37
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OPERATION
Table 13: Tower Setpoint Settings
Description Default Range PW Comments
Valve Tar-
get -Temp
65
40 –
120
O
Target value for enter-
ing condenser water
temperature
Valve Tar-
get - Lift
30
10 –
100
O
Target value for lift
pressure
Valve Con-
trol Range
- Min
10
0 –
100%
O
Minimum bypass valve
position
Valve Con-
trol Range
- Max
90
0 –
100%
O
Maximum bypass
valve position
Tower
Control
Version
Ver-
sion 2
None,
Version
1, Ver-
sion 2
T
Enable
Tower
Control
Dis -
abled
Dis -
abled,
Enabled
O
Cooling
Tower
Control
Temp
None,
Temp,
Lift
O
Selects target for tower
bypass and fan control
Tower Fan
VFD
None
None,
VFD
Stage
0, VFD
Stage 1,
VFD all
stages
O
None: No VFD Control
VFD Stage 0: VFD
independent of fan
stage outputs
VFD Stage 1: VFD on
stage 1 only
VFD all stages: VFD
on all fan stages
Tower
Valve Type
None
None,
Nor-
mally
Closed
(NC),
Normal-
ly Open
(NO),
VFD
O
None: No bypass valve
NC: Valve is normally
closed to tower
NO: Valve is normally
open to tower
VFD: bypass valve
output controls con-
denser pump VFD
Tower
Control
Mode
Auto
Effi-
ciency
Manual,
Auto,
Auto
Efficien-
cy
O
Manual: Activate man-
ual control of tower
control outputs
Auto: Set tower control
outputs to reach set
point
Auto Efficiency: When
set point can not be
reached, reduce fan
output if possible
Response
Speed
Slow
None,
Slow,
Me -
dium,
Fast
Tower control output
rate of change when
not on set point
VFD
Minimum
Speed
0 0 – 70% O
Minimum tower fan
VFD speed
Description Default Range PW Comments
Manu-
al Fan
Stages
1 0 – 3 O
Set the number of
running fan stages
when Manual Control
is enabled
Manual
Fan VFD
50 0 – 100 O
Set fan VFD speed
when Manual Control
is enabled
Manual
Valve
/ Cond
Pump VFD
90 0 – 100 O
Set bypass valve /
cond pump VFD when
Manual Control is
enabled
Cooling
Tower
Stages
2 1 – 3 O
Number of available
tower fan stages
Tower Control Setup
Setup for tower control settings in Table 13 will be accomplished
on the HMI using the Tower screen under Settings. See Figure
44 . Using the chiller unit controller, up to three digital outputs of
tower staging and two analog outputs (0-10 VDC) are available.
The two analog outputs are as follows:
1 . Bypass Valve or Condenser Pump VFD signal
2 . Tower Fan VFD signal
Tower Control Strategies
There are five possible tower control strategies that can be
selected with the Cooling Tower Control (Temp, Lift) and Tower
Control Mode (Manual, Auto, Auto Efficiency) settings:
1 . Manual: Tower control outputs are set to operator
configured values.
2 . Temp, Auto: Tower control is reactive to the delta between
set point and process value (CEWT), and the process
value rate of change. This allows the set point to be
reached by adjusting tower output over time, if possible,
given the cooling tower capability as well as outdoor air
temperature and humidity.
3 . Lift, Auto: Tower control is reactive to the delta between
set point and process value (Lift), and the process value
rate of change. This allows the set point to be reached
by adjusting tower output over time, if possible, given the
cooling tower capability as well as outdoor air temperature
and humidity.
4 . Temp, Auto Efficiency: Operates the same as Auto, except
that when tower fan output is at 100%, after 15 minutes
has elapsed, tower fan output is slowly reduced until
CEWT increases to find where increasing tower fan output
would no longer be effective in reducing CEWT. Fan output
control will return to normal if the process value increases
by more than 0.2°F or drops below the set point.
5 . Lift, Auto Efficiency: Can be selected but will operate the
same as Lift, Auto. Cooling Tower Control by temperature is
recommended.
For all strategies, the chiller unit controller can control up to three
tower fan stages, as well as a tower fan VFD and either a tower
bypass valve or condenser pump VFD. See Figure 44 .