80
Table 65 — Economizer Run Status Table
Economizer Control Point Determination Logic
Once the economizer is allowed to provide free cooling, the
economizer must determine exactly what set point it should try
to maintain. The set point the economizer attempts to maintain
when “free cooling” is located at Run Status
VIEW
EC.C.P. This is the economizer control point.
The control selects set points differently, based on the control
type of the unit. This control type can be found at Configura-
tion
UNIT
C.TYP. There are 4 types of control.
C.TYP = 1 VAV- RAT
C.TYP = 2 VAV- SP T
C.TYP = 3 TSTAT Multi-Staging
C.TYP = 4 SPT Multi-Staging
If the economizer is not allowed to do free cooling, then
EC.C.P = 0.
If the economizer is allowed to do free cooling and the Unoc-
cupied Free Cooling Mode is ON, then EC.C.P = Setpoints
SASP + Inputs
RSET
SA.S.R.
If the economizer is allowed to do free cooling and the Dehu-
midification mode is ON, then EC.C.P = the Cooling Control
Point (Run Status
VIEW
CL.C.P).
NOTE: To check the current cooling stage, go to Run Status
COOL
CUR.S.
If the C.TYP is either 1, 2, 3, or 4, and the unit is in a cool
mode, then EC.C.P = the Cooling Control Point (Run Status
VIEW
CL.C.P).
Building Pressure Control
This control sequence provides control of the building pressure
through the modulating flow rate functions of one of the modu-
lating power exhaust options or through management of the re-
turn fan option. This function also provides control of the con-
stant volume 2-stage power exhaust option.
See below for available power exhaust options for each unit
model.
LEGEND
* Sizes 075-100 only.
† Factory-installed option only.
BUILDING PRESSURE CONFIGURATION
The building pressure configurations are found at the local dis-
play under Configuration
BP. See Table 66.
Building Pressure Config (BP.CF)
This configuration selects the type of building pressure control.
• BP.CF = 0, No building pressure control
• BP.CF = 1, constant volume two-stage exhaust based on
economizer position
• BP.CF = 2, Modulating building pressure control based on
building pressure sensor
• BP.CF = 3, VFD controlling two exhaust fan motors
• BP.CF = 4, VFD control of one of the two exhaust fan mo-
tors (sizes 075-100 with high-capacity exhaust option)
• BP.CF = 5, used on sizes 075-100 with return fan option
Building Pressure Sensor (BP.S)
This configuration allows the reading of a building pressure
sensor when enabled. This is automatically enabled when
BP.CF = 2, 3, 4, or 5.
Building Pressure (±) Range (BP.R)
This configuration establishes the range in in. wg that a 4 to
20 mA sensor will be scaled to. The control only allows sen-
sors that measure both positive and negative pressure.
ITEM EXPANSION RANGE UNITS CCN POINT WRITE STATUS
ECN.P Economizer Act.Curr.Pos. 0 to 100 % ECONOPOS
EC2.P Economzr 2 Act.Curr.Pos. 0 to 100 % ECON2POS
ECN.C Economizer Act.Cmd.Pos. 0 to 100 % ECONOCMD forcible
ACTV Economizer Active ? YES/NO ECACTIVE
DISA ECON DISABLING CONDITIONS
UNV.1 Econ Act. Unavailable? YES/NO ECONUNAV
UNV.2 Econ2 Act. Unavailable? YES/NO ECN2UNAV
ENTH Enth. Switch Read High ? YES/NO ENTH
DBC DBC - OAT Lockout? YES/NO DBC_STAT
DEW DEW - OA Dewpt.Lockout? YES/NO DEW_STAT
DDBC DDBD- OAT > RAT Lockout? YES/NO DDBCSTAT
OAEC OAEC- OA Enth Lockout? YES/NO OAECSTAT
DEC DEC - Diff.Enth.Lockout? YES/NO DEC_STAT
EDT EDT Sensor Bad? YES/NO EDT_STAT
OAT OAT Sensor Bad ? YES/NO OAT_STAT
FORC Economizer Forced ? YES/NO ECONFORC
SFON Supply Fan Not On 30s ? YES/NO SFONSTAT
CLOF Cool Mode Not In Effect? YES/NO COOL_OFF
OAQL OAQ Lockout in Effect ? YES/NO OAQLOCKD
HELD Econ Recovery Hold Off? YES/NO ECONHELD
DH.DS Dehumid. Disabled Econ.? YES/NO DHDISABL
O.AIR OUTSIDE AIR INFORMATION
OAT Outside Air Temperature dF OAT forcible
OA.RH Outside Air Rel. Humidity % OARH forcible
OA.E Outside Air Enthalpy OAE
OA.D.T Outside Air Dewpoint Temp dF OADEWTMP
UNIT
CONSTANT
VOLUME
2-STAGE
MODULATING
POWER
EXHAUST
S.O.
VFD*
HIGH
CAPACITY
POWER
EXHAUST†
RETURN/
EXHAUST†
48/50P2,P4 X X S.O. X* X*
48/50P3,P5 NA X S.O. X* X*
X—Available as Factory Option
S.O. — Available as Special Order
NA — Not Available on this Unit
VFD — Variable Frequency Drive
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