66
Table 56 — Economizer Configuration Table
The enthalpy switch may also be field converted to a differ-
ential enthalpy switch by field installing an enthalpy sensor
(33CSENTSEN or HH57ZC001). The enthalpy switch/receiv-
er remains installed in its factory location to sense outdoor air
enthalpy. The additional enthalpy sensor (33CSENTSEN) is
mounted in the return airstream to measure return air enthalpy.
The enthalpy control jumper must be changed from M1 to M2
for differential enthalpy control. For the 2-wire return air en-
thalpy sensor, connect power to the Vin input and signal to the
4-20 loop input. See Fig. 8 for diagram showing the settings
and inputs on the enthalpy switch.
There is another way to accomplish differential enthalpy
control when both an outdoor and return air relative humidity
sensor are present. See Economizer Changeover Select section
below for further information.
ECONOMIZER CHANGEOVER SELECT (E.SEL) — The
control is capable of performing any one of the following
changeover types in addition to both the dry bulb lockout and
the standard external input:
E.SEL = 0 none
E.SEL = 1 Differential Dry Bulb Changeover
E.SEL = 2 Outdoor Enthalpy Changeover
E.SEL = 3 Differential Enthalpy Changeover
Differential Dry Bulb Changeover — As both return air and
outside air temperature sensors are installed as standard on
these units, the user may select this option, E.SEL = 1, to
perform a qualification of return and outside air in the enabling/
disabling of free cooling. If this option is selected and outside-
air temperature is greater than return-air temperature, free
cooling will not be allowed.
Outdoor Enthalpy Changeover — This option should be used
in climates with higher humidity conditions. The Z Series
control can use an enthalpy switch or enthalpy sensor, or the
standard installed outdoor dry bulb sensor and an accessory
relative humidity sensor to calculate the enthalpy of the air.
Setting Configuration
→
ECON
→
E.SEL = 2 requires that
the user configure Configuration
→
ECON
→
OA.E.C, the
Outdoor Enthalpy Changeover Select, and install an outdoor
relative humidity sensor. A control expansion module (CEM)
is required. Once the sensor and board are installed, enable
Configuration
→
ECON
→
ORH.S, the outdoor relative humid-
ity sensor configuration option. This will automatically enable
the CEM board, if it is not enabled already.
If the user selects one of the Honeywell curves, A,B,C or D,
then OA.E.C options 1-4 should be selected. See Fig. 9 for a
diagram of these curves on a psychrometric chart.
OA.E.C = 1 Honeywell A Curve
OA.E.C = 2 Honeywell B Curve
OA.E.C = 3 Honeywell C Curve
OA.E.C = 4 Honeywell D Curve
OA.E.C = 5 custom enthalpy curve
If the user selects OA.E.C = 5, a direct compare of outdoor
enthalpy versus an enthalpy set point is done. This outdoor
enthalpy set point limit is configurable, and is called
Configuration
→
ECON
→
OA.EN.
Depending on what Configuration
→
ECON
→
OA.E.C is
configured for, if the outdoor enthalpy exceeds the Honeywell
curves or the outdoor enthalpy compare value (Configuration
→
ECON
→
OA.EN), then free cooling will not be allowed.
NOTE: If the user wishes to disable the standard enthalpy
control from running concurrently, a field-supplied jumper
must be installed between TB201 terminals 3 and 4.
Differential Enthalpy Changeover — This option compares
the outdoor-air enthalpy to the return air enthalpy and chooses
the option with the lowest enthalpy. This option should be
used in climates with high humidity conditions. This option
uses both humidity sensors and dry bulb sensors to calculate
the enthalpy of the outdoor and return air. An accessory
outdoor air humidity sensor (ORH.S) and return air humidity
sensor (RRH.S) are used. The outdoor air relative humidity
sensor config (ORH.S) and return air humidity sensor config
(Configuration
→
SENS
→
RRH.S) must be enabled.
NOTE: If the user wishes to disable the standard enthalpy
control from running concurrently, a field-supplied jumper
must be installed between TB201 terminals 3 and 4.
Outdoor Dewpoint Limit Check — If an outdoor relative
humidity sensor is installed, the control is able to calculate the
ITEM EXPANSION RANGE UNITS CCN POINT DEFAULT
EC.EN Economizer Installed? Yes/No ECON_ENA Yes
EC2.E Econ.Act.2 Installed? Yes/No ECON_TWO No
EC.MN Economizer Min.Position 0 - 100 % ECONOMIN 5
EC.MX Economizer Max.Position 0 - 100 % ECONOMAX 98
E.TRM Economzr Trim For SumZ ? Yes/No ECONTRIM Yes
E.SEL Econ ChangeOver Select 0 - 3 ECON_SEL 0
OA.E.C OA Enthalpy ChgOvr Selct 1 - 5 OAEC_SEL 4
OA.EN Outdr.Enth Compare Value 18 - 28 OAEN_CFG 24
OAT.L High OAT Lockout Temp -40 - 120 dF OAT_LOCK 60
O.DEW OA Dewpoint Temp Limit 50 - 62 dF OADEWCFG 55
ORH.S Outside Air RH Sensor Enable/Disable OARHSENS Disable
CFM.C OUTDOOR AIR CFM CONTROL
OCF.S Outdoor Air CFM Sensor Enable/Disable OCFMSENS Disable
O.C.MX Economizer Min.Flow 0 - 20000 CFM OACFMMAX 2000
O.C.MN IAQ Demand Vent Min.Flow 0 - 20000 CFM OACFMMIN 0
O.C.DB Econ.Min.Flow Deadband 200 - 1000 CFM OACFM_DB 400
E.CFG ECON.OPERATION CONFIGS
E.P.GN Economizer Prop.Gain 0.7 - 3.0 EC_PGAIN 1
E.RNG Economizer Range Adjust 0.5 - 5 ^F EC_RANGE 2.5
E.SPD Economizer Speed Adjust 0.1 - 10 EC_SPEED 0.75
E.DBD Economizer Deadband 0.1 - 2 ^F EC_DBAND 0.5
UEFC UNOCC.ECON.FREE COOLING
FC.CF Unoc Econ Free Cool Cfg 0-2 UEFC_CFG 0
FC.TM Unoc Econ Free Cool Time 0 - 720 min UEFCTIME 120
FC.L.O Un.Ec.Free Cool OAT Lock 40 - 70 dF UEFCNTLO 50
ACT.C ECON.ACTUATOR CONFIGS
SN.1.1 Econ Serial Number 1 0 - 255 ECON_SN1 0
SN.1.2 Econ Serial Number 2 0 - 255 ECON_SN2 0
SN.1.3 Econ Serial Number 3 0 - 255 ECON_SN3 0
SN.1.4 Econ Serial Number 4 0 - 255 ECON_SN4 0
SN.1.5 Econ Serial Number 5 0 - 255 ECON_SN5 0
C.A.L1 Econ Ctrl Angle Lo Limit 0 - 90 ECONCALM 85
SN.2.1 Econ 2 Serial Number 1 0 - 255 ECN2_SN1 0
SN.2.2 Econ 2 Serial Number 2 0 - 255 ECN2_SN2 0
SN.2.3 Econ 2 Serial Number 3 0 - 255 ECN2_SN3 0
SN.2.4 Econ 2 Serial Number 4 0 - 255 ECN2_SN4 0
SN.2.5 Econ 2 Serial Number 5 0 - 255 ECN2_SN5 0
C.A.L2 Econ 2 Ctrl Angle Lo Limit 0 - 90 ECN2CALM 85