Configuration
Configuring The Controller
Analog Output #2
In this example Analog Output #2 is configured for the “System Pump
VFD” output. In
Figure 34
Item #1 it indicates it has a Control Type of
“Reverse Acting Floating Point”.
Item #2 indicates the Control Source for this relay will be the Loop Dif-
ferential Pressure (“Loop Pressure”) on AIN4. Item #3 indicates that the
“Max Setpoint” will be 33.0 P.S.I. and the “Deadband” will be 3.0 P.S.I.
Item #4 Shows the Enabling Relay to be the “System Active” output
configured on (Relay #8). This means that in addition to the “Loop
Pressure” being above setpoint the “System Active” relay must also be
activated for the “System Pump VFD” to modulate.
Item #5 indicates it also has Output Limits of :
Max Voltage = 10.0 VDC
Min Voltage = 0.0 VDC.
Item #6 shows that its calculation settings are:
Calculation Interval (Controls Speed) = 3.0 Sec
Proportional Control Window = 1.0 P.S.I.
With this configuration sequence the “System Pump VFD” will modulate
its speed towards 0% (0 VDC) when the “Loop Pressure” P.S.I. (AIN4)
is 3.0 P.S.I. above the 33.0 P.S.I. setpoint (36.0 P.S.I.) and the “System
Active” (Relay #8) output is active.
When the “Loop Pressure” temperature (AIN2) is between 36.0 P.S.I.
and 30.0 P.S.I. and the “System Active” (Relay #8) output is active, the
“System Pump VFD” will maintain its speed at a constant level.
The “System Pump VFD” will modulate its speed towards 100%
(10 VDC) when the “Loop Pressure” P.S.I. (AIN4) is 3.0 P.S.I. below
the 33.0 P.S.I. setpoint (30 P.S.I.) and the “System Active” (Relay #8)
output is active.
Analog Output #3
In this example Analog Output #3 is configured for the “Mod Cooling”
output. In
Figure 35
Item #1 it indicates it has a Control Type of “Direct
Acting Floating Point”.
Item #2 indicates the Control Source for this relay will be the Tower Re-
turn Water Temperature (“TW Return”) on AIN2. Item #3 indicates that
the “Max Setpoint” will be 82.0° F and the “Deadband” will be 3.0° F.
Item #4 Shows the Enabling Relay to be the “System Active” output
configured on (Relay #8). This means that in addition to the “TW Return“
temperature being above setpoint the “System Active” relay must also
be activated for the “Mod Cooling” to modulate.
Item #5 indicates it has Output Limits of :
Max Voltage = 10.0 VDC
Min Voltage = 2.0 VDC.
Item #6 shows that its calculation settings are:
Calculation Interval (Controls Speed) = 3.0 Sec
Proportional Control Window = 1.0° F
With this configuration sequence the “Mod Cooling” will modulate
towards 100% (10 VDC) when the “TW Water” temperature (AIN2)
is 3.0° F above the 82.0° F setpoint (85.0° F) and the “System Active”
(Relay #8) output is active.
When the “TW Water” temperature” (AIN2) is between 85.0° F and
79.0° F and the “System Active” (Relay #8) output is active the “Mod
Cooling” will maintain its modulation percentage at a constant level.
The “Mod Cooling” will modulate its speed towards 0% (2 VDC) when
the “TW Return “ temperature” (AIN2) is 3.0° F below the 82.0° F
setpoint (79.0° F) and the “System Active” (Relay #8) output is active.
35
WSHP Loop Controller
GPC-XP Guide
