RRU-SVX01F-EN
19
Sequence of Operation
Terminology
Controls
Relays
Sensors
Operator Set Points
Optional—Requires Hot Gas Reheat
(HGRH)
Optional—Requires Space Temperature &
RH Sensors
Power On—Control Input
“Occupied”
Three Phase Unit Disconnect ON
RRUCM and RTRM Initialize
Control Input Contact CLOSED at RRUTS – 7 & 8
“Occupied” Ventilation Mode
RRUCM Energizes the O/Air Damper Actuator (ODA)
through ODR / RDR Relay R1
O/Air Damper OPENS
R/Air Damper (Optional) CLOSES through ODR / RDR
Relay R1
O/Air Damper makes the Outdoor Damper End Switch
(DES)
RRUCM Energizes the Indoor Fan Motor (IDM) through
IDM Relay R2
R2 Energizes RTRM Terminal G and IDM STARTS
Fan Failure Switch (FFS) Proves Airflow
VENTILATION MODE Established
“Occupied” Conditioning Modes
Outdoor Air Temperature (OTS) and Outdoor Air Relative
Humidity (ORH) sensors located in the Outdoor Air Inlet
controls call for the following operational modes based on
Outdoor Air conditions.
COOLING MODE
Compressor 1 ON
DEHUMIDIFICATION MODE
Compressor 1 or Compressor 1 & 2 ON
HOT GAS REHEAT (OPTIONAL)
Compressor 1 or Compressor 1 & 2 ON
HEATING MODE
Modulating Heat
“Occupied” Cooling Mode
Call for cooling is based on Outdoor Air Temperature
(OAT) sensed at the Outdoor Air Temperature Sensor
(OTS). Y1 – O/Air Cooling Enable Set Point (CSP) is
operator adjustable between 68 F and 80°F.
RRUCM
ROD
DES
APS
FFS
RCC
MGA
GV
IGN
TNS5
TNS6
HTC
RTRM
RHV
SSP
ODA
RDA
R
G
Y1
Y2
LTB
RRUTS
RRU Main Control Module
Remote Operator Display
Outdoor Damper End Switch
Air Proving Switch
Fan Failure Switch
Refrigeration Capacity Controller
Modulating Gas Actuator
Gas Valve
Ignition Control Module
Gas Ignitor
Gas Ignitor Power Transformer
High Temperature Cutout
ReliaTel Refrigeration Module
Reheat Valve
Space Temperature Set Point (Dial)
Outdoor Air Damper Actuator
Return Air Damper Actuator
24VAC Power - Terminal R (RTRM)
Indoor Fan Motor – Terminal G (RTRM)
Cooling Stage 1 – Terminal Y1 (RTRM)
Cooling Stage 2 – Terminal Y2 (RTRM)
Low Voltage Terminal Block
Control Terminal Strip (Field Connections)
R1
R2
R3
R4
R5
R6
R7
R8
R9
ODR / RDR (O/Air & R/Air Damper Actuator)
IDM (Indoor Fan Motor)
COOL 1 (Cooling – Stage 1)
COOL 2 (Cooling – Stage 2)
HGRH (Hot Gas Reheat Valve)
HEAT (Heat Relay)
PV (Gas Valve & Gas Ignitor)
MV (Gas Ignitor Disconnect)
ESR (Emergency Stop Relay)
OTS
STS
STC
ORH
SHC
Outdoor Air Temperature (OAT)
Supply Air Temperature (SAT)
Space Temperature (ST)
Outdoor Humidity (ORH)
Space Humidity (SRH)
CSP
OES1
OES2
HESP
HSP
MHSP
SLC
SLT
SHC
SHT
Y1 – O/Air Cooling Enable
Y1 – O/Air Dehumid Enable
Y2 – O/Air Dehumid Enable
O/Air Heating Enable
Occupied S/Air Heating
Minimum Supply Air Heating
S/Air Low Cutoff (Time)
S/Air Low Cutoff (Temperature)
S/Air High Cutoff (Time)
S/Air High Cutoff (Temperature)
HGRHD
HGRH Control Dead Band
OSSP
OSHO
OSRS
NHSP
NCSP
NRSP
NSAS
Occupied Space Cooling
Occupied Space Heating Offset
Occupied Space Humidity
Unoccupied Space Heating
Unoccupied Space Cooling
Unoccupied Space Humidity
Unoccupied S/Air Heating
