Sequence of Operation
RRU-SVX01F-EN
21
The active supply air heating setpoint will be displayed on
the System Heating Status Screen on the ROD.
“Occupied” Space Temperature Override
Control (Optional)
Use of this option requires the optional Space
Temperature (STC) sensor and requires the operator to
INSTALL the STC Option at the ROD.
RRU operation in HEATING or COOLING modes is based
solely on outdoor air conditions. The use of this option
permits space conditions to either reset the Y1 - O/Air
Cooling Enable Set Point (CSP) or changes the Occupied
S/Air Heating Set Point (HSP).
This option controls space cooling temperature based on
the Occupied Space Cooling Set Point (OSSP) and heating
temperature based on the OSSP minus Occupied Space
Heating Offset Set Point (OSHO).
The OSSP can be controlled by either the Space
Temperature Set Point Dial (SSP) or the ROD.
The operator must select SSP or RRUCM control at the
ROD.
COOLING CONTROL: A Space temperature above OSSP
resets the Y1 - O/Air Cooling Enable Set Point (CSP). CSP
can only be reset downwards until OSSP is satisfied. The
reset set point will return to the initial set point when the
OSSP set point is satisfied. Compressor 1 will de-energize
when space temperature falls to Space Cooling
Setpoint - 3°F.
HEATING CONTROL: A Space temperature above OSSP
lowers the SAT. Space temperatures below the OSSP
minus OSHO raise the SAT. SAT will modulate between
the upper and lower Occupied S/Air Heating Set Points
(HSP) through the RRUCM in an attempt to maintain the
desired space temperature. If space temperature = Space
Heating Se 1°F, RRUCM will reduce burner output
to maintain supply air Minimum Heating Setpoint.
“Occupied” Space Humidity Override
Control (Optional)
Use of this option requires the optional Space Humidity
(SHC) sensor and requires the operator to INSTALL the
SHC Option at the ROD.
RRU operation in DEHUMIDIFICATION mode is based
solely on outdoor air conditions. The use of this option
permits space conditions to reset Y1 & Y2 – O/Air Dehumid
Enable Set Points (OES1 & OES2).
The SHC inputs space relative humidity readings to the
RRUCM. The RRUCM resets OES1 and OES2 set points in
an attempt to maintain the space humidity. The Occupied
Space Humidity Set Point (OSRS) can be adjusted
between the OSRS low and high limit set points as defined
by the operator at the ROD. When the space humidity rises
above the OSRS the RRUCM will reset OES1 and or OES2
set points. These reset set points can be viewed at the ROD
as Y1 & Y2 – Active O/Air Dehumid Set Points. DEHUMID
1 and DEHUMID 2 will operate as describe in the
Dehumidification Mode of this document. OES1 and OES2
can only be reset downwards until OSRS is satisfied. The
reset is factory set to reduce OES1 and OES2 up to 5 Btu
each in 1 Btu increments. When the OSRS set point is
satisfied, the reset set points will return to initial set points.
Power On—Control Input
“Unoccupied”
Change control Input at RRUTS – 7 & 8 from OCCUPIED
(CLOSED) to UNOCCUPIED (OPEN)
Cooling, Dehumidification or Heating modes De-Energize
IDM De-Energized
O/Air Damper CLOSES following 30-second Off-Delay
“Unoccupied” Operation (Optional)
Use of this option for unoccupied heating and cooling
control requires the optional Space Temperature (STC)
sensor and requires the operator to INSTALL the STC
Option at the ROD.
Use of this option for unoccupied space humidity control
requires the optional Space Humidity (SHC) sensor and
requires the operator to INSTALL the SHC Option at the
ROD.
Use of the optional R/Air Damper for unoccupied
100 percent recirculating cooling and dehumidification
requires the operator to INSTALL the R/Air Damper at the
ROD. On call for heating the R/Air Damper remains
CLOSED and the O/Air Damper OPENS. The O/Air Damper
will OPEN on call for unoccupied heating, cooling or
dehumidification if the R/Air Damper is NOT INSTALLED.
“Unoccupied” Indoor Fan and Damper
Sequence
Space conditions control RRU “Unoccupied” operation
based on “Unoccupied” RRUCM set points. Set points
include Unoccupied Space Cooling Set Point (NCSP),
Unoccupied Space Humidity (NRSP) and Unoccupied
Space Heating Set Point (NHSP).
“Unoccupied” Heating Mode
“UNOCCUPIED” Contact OPEN at RRUTS – 7 & 8
OCCUPIED SPACE COOLING SET POINT (OSSP):
65°F–80°F
72°F DEFAULT
OCCUPIED SPACE HEATING OFFSET SET POINT
(OSHO):
2°F–20°F
4°F DEFAULT
OCCUPIED S/AIR HEATING SET POINT (HSP):
LOWER HSP = 40°F
UPPER HSP = 80°F
40°F–90°F
60°F DEFAULT
OR LOCAL
MINIMUM (SUPPLY AIR) HEATING SET POINT
45°F–70°F
45°F DEFAULT
OCCUPIED SPACE HUMIDITY SET POINT (OSRS): 40%–75% RH
60% RH DEFAULT
