Orion System OE392-10 System Manager TS - Manual (Page 45)

SMTS Technical Guide
VCM, VCM-X & VCB-X Controllers
45
VCB-X Controllers
Cooling Minimum 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.
Mod Cooling Time Period
The Mod Cooling Time Period is the delay before another Modulating
Cooling Signal increase or decrease can be made and is user-adjustable.
Short Mod Cooling Time Periods may cause hunting of the Modulat-
ing Cooling Signal. This is the rate at which the Modulating Cooling
Signal is calculated. High limit = 240 seconds; Low limit = 5 seconds;
Default = 30 seconds.
Heating Stage Up Delay Time
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 Stage Down Delay Time
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 Minimum 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 = 5 minutes.
Heating Minimum 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 minutes; Default = 1 minute.
Mod Heating Time Period
The Mod Heating Time Period is the delay before another Modulating
Heating Signal increase or decrease can be made and is user-adjustable.
Short Mod Heating Time Periods may cause hunting of the Modulat-
ing Heating Signal. This is the rate at which the Modulating Heating
Signal is calculated. High limit = 240 seconds; Low limit = 5 seconds;
Default = 30 seconds.
Heat/Cool Changeover Delay
The amount of time that must elapse after the last stage has turned off
before switching to the opposite HVAC mode. High limit = 20 minutes;
Low limit = 0 minutes; Default = 5 minutes.
VCB-X Staging Delays
Mechanical Heat/Cool Alarm Timer
Enter a time delay between 0-240 minutes for a delay in the time that it
takes the Mechanical Heat/Cool Alarm to be generated. When Heating
or Cooling Mode is initiated and staging is activated, if the Supply Air
Temperature does not rise or fall 5°F within this time period, a Mechani-
cal Heating or Cooling failure alarm will be generated. The Alarm is
for Status Reporting only. The HVAC unit will continue to run. This
alarm does not apply if Modulating Cooling or Heating are confi gured.
High limit = 240 minutes; Low limit = 0 minutes; Default = 15 minutes.
Heat Pump Aux Heat Delay
If the Supply Air is not reaching setpoint, Auxiliary Heat can be added
after this amount of delay running at full heating. High limit = 60 min-
utes; Low limit = 0 minutes; Default = 3 minutes.
Economizer Control Loop Time
This is the time period between changes to the Economizer position.
High limit = 30 seconds; Low limit = 1 seconds; Default = 10 seconds.
Building Pressure Control Rate
The Building Pressure Control Rate is the time period between changes
to the Building Pressure Control signal. High limit = 30 seconds; Low
limit = 1 second; Default = 10 seconds.
Fan Starting Delay
Enter the number of seconds you want the fan to delay starting. This is
the Supply Fan Starting Delay initiated whenever the VCB-X initiates
Supply Fan operation upon going occupied or after power-up. This is
useful when you are using multiple VCB-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 VCB-X should be set with
staggered Fan Starting Delay Setpoint values. When the -1 value is used,
it multiplies each VCB-X Controller’s address by 5 and uses this value
in seconds as the Fan Starting Delay. This provides a staggered start for
each VCB-X Controller on the system without having to individually
set each VCB-X Controller for its own time delay. High limit = 240
seconds; Low limit = -1 second; Default = -1 second.
Fan Purge Mode Delay
This is the number of seconds you want the unit to stay in Purge Mode
before going into Occupied Mode. In Purge Mode, the fan runs with
the Economizer at minimum position and all Cooling and Heating is
de-energized. High limit = 900 seconds; Low limit = 0 seconds; Default
= 10 seconds.
Static/ Fan Speed Control Rate
This value determines the time interval between changes to the Supply
Fan Speed or the Bypass Damper Position during duct static pressure
control. It also determines the time interval between changes to the Fan
Speed during Single Zone VAV Reset of the Supply Fan VFD Speed.
High limit = 30 seconds; Low limit = 1 second; Default = 10 seconds.