Orion System OE392-10 System Manager TS - Manual (Page 32)

VCM & VCM-X Controllers
SMTS Technical Guide 32
VCM & VCM-X Staging Delay & Miscellaneous Setpoints
Misc
Heat Pump Delay
If your VCM-X is confi gured to operate as a Heat Pump, the Heat Pump
Auxiliary Heating Delay Setpoint can be confi gured to provide a time delay
period before Auxiliary Heating Stages can be activated once activation
of the Compressor Heating Stages have been initiated. High limit = 30
minutes; Low limit = 0 minutes; Default = 3 minutes.
Miscellaneous Setpoints
Touch the
< Miscellaneous>
button to access the
Miscellaneous Setpoint Screens.
Heating Minimum VFD
If the Supply Fan VFD signal falls below this setpoint, Heating will be
disabled. The Main Fan VFD signal must be at or above this percentage
before any heat is allowed to activate. High limit = 100%; Low limit =
0%; Default = 30%.
Mod Cooling Window
The Modulating Cooling Window is the control range of the Modulating
Signal above and below the Active Supply Air Setpoint. The larger the
Modulating Cooling Window, the smaller the signal adjustment per Time
Period will be for each ºF the supply air is from the Active Supply Air
Temperature Setpoint. If the Supply Air Temperature is this amount away
from the SAT setpoint, 10% of the possible output signal will be applied.
High limit = 30ºF; Low limit = 5ºF; Default = 5ºF.
Mod Cooling Time Period
The Time Period is the delay before another signal increase or decrease
can be made and is user-adjustable. Short Time Periods may cause hunt-
ing of the Modulating Signal. This is the rate at which the Modulating
Cooling Signal is calculated. High limit = 250 seconds; Low limit = 5
seconds; Default = 30 seconds.
Mod Heating Window
The Modulating Heating Window is the control range of the Modulating
Signal above and below the Active Supply Air Setpoint. The larger the
Modulating Heating Window, the smaller the signal adjustment per Time
Period will be for each ºF the supply air is from the Active Supply Air
Temperature Setpoint. If the Supply Air Temperature is this amount away
from the SAT setpoint, 10% of the possible output signal will be applied.
High limit = 30ºF; Low limit = 5ºF; Default = 5ºF.
Mod Heating Time Period
The Mod Heating Time Period is the delay before another signal increase
or decrease can be made and is user-adjustable. Short Time Periods may
cause hunting of the Modulating Signal. This is the rate at which the
Modulating Heating Signal is calculated. High limit = 250 seconds; Low
limit = 5 seconds; Default = 5 seconds.
Cooling Min Off Time
Once a Compressor has been staged back off, it must remain off for this
amount of time to prevent short cycling. High limit = 15 minutes; Low
limit = 3 minutes; Default = 3 minutes.
Mechanical Fail Timeout
When Heating or Cooling Mode is initiated and staging is activated, if the
Supply Air Temperature does not rise or fall 5°F within the Mechanical
Fail Timeout Setpoint, a Mechanical Heating or Cooling failure alarm
will be generated. The Alarm is for status reporting only. The HVAC unit
will continue to run. High limit = 255 minutes; Low limit = 0 minutes;
Default = 15 minutes.
Heating Stage Down
This is the amount of time that must elapse between each Heat Stage
deactivation to prevent all Heat Stages from deactivating at once as the
heating demand decreases. High limit = 15 minutes; Low limit = 1 minute;
Default = 1 minute.
Heating Stage Up
This is the amount of time that must elapse between each Heat Stage
activation to prevent all Heat Stages from activating at the same time
due to large heating demands. High limit = 15 minutes; Low limit = 3
minutes; Default = 3 minutes.
Heating Min Run Time
This is the minimum amount of time the Heat Stages must remain on
once they have been activated. This overrides the Stage Down Delay if
that is not as long as this delay. High limit = 15 minutes; Low limit = 2
minutes; Default = 2 minutes.
Heating Min Off Time
Once a Heat Stage has been staged back off, it must remain off for this
amount of time to prevent short cycling. High limit = 15 minutes; Low
limit = 1 minute; Default = 1 minute.
Warm-up Timeout
If the equipment has entered the Morning Warm-up Mode, it will remain
in that mode until the Return Air Temperature rises above the Morning
Warm-up Setpoint or until this Warm-up Timeout expires. The Warm-up
Timeout must be greater than zero for Morning Warm-up to occur. High
limit = 240 minutes; Low limit = 0 minutes; Default = 60 minutes.
Fan Starting Delay
This is the Supply Fan Starting Delay Timer initiated whenever the VCM-
X initiates Supply Fan operation. This is useful when you are using mul-
tiple VCM-X-controlled HVAC units and want to be sure that all the units
do not start at exactly the same time when the Occupied schedule occurs.
Each VCM-X should be set with staggered Fan Starting Delay Setpoint
values. When the 255-second default setpoint is used, it multiplies each
VCM-X controller’s address by 5 and uses this value in seconds as the
Fan Starting Delay Time. This provides a staggered start for each VCM-X
controller on the system without having to individually set each VCM-X
controller for its own time delay. High limit = 255 seconds; Low limit =
0 seconds; Default = 255 seconds.