36
PFS 155C - 315C
OM 135
Menu 14, Cooling Tower
Press the "NEXT MENU" key and Menu 14 will be displayed. This menu is password protected and requires the
operator password.
Item
Screen
Line
Display
Field
Range
1
1
Tower Control=Yes
1
Yes-No
Tower Stages=2
2
1-2
2
StageUp Time=2Min
1
1-60 Min
StageDn Time=5Min
2
1-60 Min
3
Stage Differential=3.0
o
F
1
1-10
o
F
2
1
Stage #1 On=70.0
o
F
1
40-120
o
F
Stage #4 On=85.0
o
F
2
40-120
o
F
2
Stage #2 On=75.0
o
F
1
40-120
o
F
3
Stage #3 On=80.0
o
F
1
40-120
o
F
Tower Control=
Set this value to 'yes' for fan staging control or bypass valve control and 'no' if condenser water
temperature is not controlled by the MicroTech.
Tower Stages=
This value will determine how the MicroTech calculates the time to increase or decrease the cooling
tower controlling sequence. The number of stages refers to cooling tower fans or to bypass valve control.
Stageup Time=
This value will delay the MicroTech from starting the staging control. This can be used to provide
specific system control requirements.
Stagedn Time=
This value will delay the MicroTech from staging down for the time specified. This can be used to
provide specific system control requirements.
Stage Differential=
This value is the control band for the fan staging control logic. This value must be exceeded to
stage up or down.
Stage #1 On=
This value determines when the first stage control will start. This value plus 1/2 the stage differential
determines the control point value. This value is active on stage up and stage down.
Stage #2-4 On=
Same as Stage #1 On=.
Menu 15, Clg Tower Valve
Press the "NEXT MENU" key and Menu 15 will be displayed. This menu is password protected and requires the
operator password.
Item
Screen
Line
Display
Field
Range
1
1
Valve Control=None
1
None
Valve Setpoint
Stage Setpoint
2
Valve Spt=65.0
o
F
1
40-99.5
o
F
Valve Deadb=2.0
o
F
2
1.0-10.0
o
F
3
Min Position=20%
1
0-50%
Max Position=80%
2
50-100%
2
1
Valve Type=NC
1
NC to Tower
NO to Tower
2
Mod Limit=7.5
o
F
1
4.0-25.0
o
F
Sample Time=15Sec
2
1Sec-15Min
3
Max Change=4%
1
1-20%
PA Time=47.0Min
2
1.0 60.0 Min
3
1
Min Start Pos=0%
1
0-100%
Max Start Position=100%
2
0-100%
2
Min Pos At=60
o
F
1
0-99.5
o
F
Max Pos At=90
o
F
2
0-99.5
o
F
Valve Control=
A value must be selected telling the MicroTech which type of control will be used for the tower valve. If
none is selected, the remaining values are not required for tower control.
Valve Spt=
This value is the water temperature the MicroTech will maintain by modulating the tower valve.
Valve Deadb=
This value is the control dead band that is used in the MicroTech when calculating control actions.
