Programming, Vav/zone controller setpoint screens, Sa controller operator interface 48 – Orion System SA Controller User Manual

Page 48: Vav/zone controller setpoints, Zone

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Zone

Zone

Programming

SA Controller Operator Interface

48

VAV/Zone Controller Setpoint Screens

VAV/Zone Controller Setpoints

Setpoint Screen #1 - Occupied Setpoints

XX Box Spts IDXXXX
Occupied Setpoints

Cooling.....: XXºF
Heating.....: XXºF

Enter the Occupied Cooling Setpoint as the maximum temperature
you would like the zone to reach before modulating the damper open
to bring in more cold air to cool the space. Enter the Occupied Heat-
ing Setpoint
as the minimum temperature you would like the zone to
reach before activating the Reheat Stages on the optional Expansion
Relay board. If this is a Cooling Only box that doesn’t contain reheat,
this setpoint will be ignored.

Description

Minimum

Default

Maximum

Cooling Setpoint

50ºF

74ºF

90ºF

Heating Setpoint

50ºF

70ºF

90ºF

Setpoint Screen #2 - Unoccupied Setbacks

XX Box Spts IDXXXX

Unoccupied Setbacks

Cooling SetUp: XXºF
Heating SetBk: XXºF

During unoccupied hours, the Occupied Cooling Setpoint is adjusted up
by the amount entered for the Cooling SetUp. The Occupied Heating Set-
point is adjusted down by the amount entered for the Heating SetBk.

Description

Minimum

Default

Maximum

Cooling SetUp

0ºF

+10ºF

+30ºF

Heating SetBk

0ºF

-10ºF

-30ºF

Setpoint Screen #3 - AHU Heat Call Space Temp

XX Box Spts IDXXXX

AHU Heat Call

Space Temp...: XXºF

This setpoint allows you to set a Space Temperature that will cause the
VAV/Zone Controller to send a call for heat to the HVAC unit. This only
occurs in the Unoccupied Mode.

Description

Minimum

Default

Maximum

AHU Heat Call Space Temp

50ºF

70ºF

90ºF

Setpoint Screen #4 - Damper Airfl ow Integral

XX Box Spts IDXXXX

Damper/Airflow Spt

Integral [Ki]..: XXX

The VAV/Zone Controller normally opens its damper based on a Pro-
portional Error from Setpoint. That means if the zone temperature is 4°F
from setpoint, the damper would be 100% open, or it would be modulat-
ing to provide the Maximum CFM on Pressure Independent boxes. If
the error is less than 4°F, the damper may stagnate at that position and
never satisfy the zone. If you add Integral into the damper calculation
process, this will cause the damper or airfl ow calculations to continue to
increase as long as the zone temperature is still above the setpoint. That
means it can provide 100% or Maximum CFM before the 4°F error is
achieved, bringing the zone under control faster than it normally would.
Start with a small (5 or 10) value, if you use this, and monitor the effect
it has. If you enter too large a value, you can create “hunting” situations
that can cause the damper actuator to prematurely wear out.

Description

Minimum

Default

Maximum

Integral

0

0

100

Setpoint Screen #5 - Damper Airfl ow Max &

Vent Min

XX Box Spts IDXXXX

Damper/Airflow Spt

Maximum..: XXX %

Vent Min.: XXX %

The VAV/Zone Controller will not allow the damper or airfl ow calcula-
tion to exceed the Maximum setpoint while it is allowing the damper to
modulate. During Vent mode when there is no heating or cooling demand,
the damper or airfl ow will maintain at least the Vent Min amount of
airfl ow into the zone for ventilation.

Description

Minimum

Default

Maximum

Maximum

0% or 0 CFM

100% or

1000 CFM

100% or

30000 CFM

Vent Min

0% or 0 CFM

25% or

250 CFM

100% or

30000 CFM

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