26
User Setup – Compressor Staging
Figure 51 - User Setup – Compressor Staging Setup
Screen
Table 13 – Compressor Staging Setup Parameters
Menu Item
Description
Default Value
Staging
Mode
In Auto Mode, the control system
adjusts the number of staged
compressors relative to the
demand and available
compressors. In manual mode, the
number of staged compressors
depends on the Manual Mode
Value relative to available
compressors.
AUTO
Pressure
Differential
Assistance
(PDA)
Pressure Differential Assistance
will energize all compressors
when the circuit first starts for the
time specified in the PDA Delay
parameter.
OFF
PDA Delay
Delay time to run ll compressor
on circuit start
30 sec
Kp
Proportional PID value
1.000
Ti
Integral PID value
100.000
Td
Derivative PID value
0.000
S
tage ΔT
If the process value rises above
the set point by this differential,
the first compressor will turn on.
1°F
Destage ΔT
If the process value drops below
the set point by this differential,
all compressors turn off.
5°F
Stage to
Stage Delay
This is the minimum delay
duration between stages on
multiple compressors. During this
time delay, the demand percent
calculation ceases to allow the
impact of the newly staged
compressor to influence the
system.
120 sec
User Setup – Stage Order
Compressor Stage Order Screen
The Compressor Stage Order Screen –
depicts the stage order of the local chiller. The stage
order calculation uses the hours entered in the auto-
stage threshold parameter. The intent is to run the
compressors with the least amount of hours first to
help equalize the run hours of all the compressors
Figure 52 - User Setup – Stage Order Setup Screen
Table 14 – Stage Order Setup Parameters
Menu Item
Description
Default Value
Stage Mode
Automatic: calculates the stage
order by the AUTO STAGE
THRESHOLD parameter
Manual: Manually enter the stage
order
AUTO
Auto Stage
Threshold
The number of run hours before
recalculating the stage order
24 HOURS
Minutes Until
Auto Stage
Minutes remaining until the stage
calculation occurs
None
