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SYSTEM SPECS (LADDER)
Demand:
0%-020%
020%-040%
040%-060%
060%-080%
080%-100%
100%
Screen F
SYSTEM SELECTION: MODULATING PUMP
If Modulating Pump has been set as the system selection
(see page 17), the controller allows the user to configure
a ratio between the pump speed and the cooling demand
(in %) as well as between the pump speed and the outside
temperature (OT).
When the cooling demand varies, the pump speed will vary
proportionally.
The pump speed can also be influenced by the outside
temperature (OT). This allows the system to use less
water when OT is low. The user must first set a low outside
temperature (OutTempLW) and a high outside temperature
(OutTempLW + OutTempLW band). Then, the user can
set a minimum and maximum pump speed for low outside
temperature (LOT) and a minimum and maximum pump
speed for high outside temperature (HOT).
LOT
= Low Outside Temperature = OutTempLW
HOT
= High Outside Temperature = OutTempLW +
OutTempLW band
OutTempLW = Outside temperature when the pump
follows the cooling demand at lower speeds (from min to
max speed for LOT).
OutTempLW + OutTempLW band = Outside temperature
when the pump follows the cooling demand at higher speeds
(from min to max speed for HOT).
Also, the user must choose between Proportional and
Range:
Proportional: The pump speed will be lower as OT approaches
OutTempLW and higher as OT approaches OutTempLW +
OutTempLW band, following the cooling demand.
Range: When OT is equal or below OutTempLW (LOT), the
pump will run at lower speeds, following the cooling demand.
When OT is equal or above OutTempLW + OutTempLW
band (HOT), the pump will run at higher speeds, following
the cooling demand. When OT is between OutTempLW
and OutTempLW + OutTempLW band, the pump speed
will remain the same; this means if OT rises and passes
OutTempLW, pump continues to run at low speeds, and If
OT drops and passes OutTempLW + OutTempLW band,
pump continues to run at high speeds.
Screen G and Screen H show an example of a Modulating
Pump configuration.
R
Pulse
006/060s
014/060s
023/060s
032/060s
041/060s
050/060s
SYSTEM SPECIFICATIONS
PumpON when CD is: 010%
OutTempLW:
OutTempLW band:
OutTempLW Mode:
Screen G
SYSTEM SPECIFICATIONS
Water pump
LOT HOT
Max spd: 072-082%
M in spd: 040-050% 040%
Acceleration
on start:
Screen H
In this example, the OutTempLW is set to 22
corresponds to the low outside temperature point where the
pump will run at lower speeds (LOT column on Screen H),
depending on the cooling demand. Since the OutTempLW
band is set to 5
C, then the high outside temperature point
o
(OutTempLW + OutTempLW band) is equal to 27
the pump will run at higher speeds (HOT column on Screen
H), depending on the cooling demand. Column RES on
Screen H shows the resulting minimum and maximum
speeds depending on OT.
The cooling demand is expressed in % as shown in Graph
1 on page 5. For each cooling demand percentage,
there is an associated pump speed range in %, as shown
on Graph 8. For example, for a 100% cooling demand, the
pump speed is 72% at low outside temperature and 82% at
high outside temperature.
The next three graphs represent the settings as shown on
Screen G and Screen H.
Cooling demand (CD) changes the pump speed
100%
90%
80%
70%
60%
50%
Pump speed variation depending on OT
40%
30%
20%
10%
0%
0%
20%
40%
60%
COOLING DEMAND
Graph 8 Pump speed range vs cooling demand (according to
parameters on Screen H)
22.0
C
o
05.0
C
o
Prop
RES
072%
01%/sec
C, which
o
C, where
o
82 Max spd (HOT)
72 Max spd (LOT)
50 Min spd (HOT)
40 Min spd (LOT)
80%
100%
9
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