Carrier WEATHERMAKER 48/50AJ Operation And Service Manual page 62

ITEM
EC.EN Economizer Installed?
EC.MN Economizer Min.Position
EC.MX Economizer Max.Position
E.TRM Economzr Trim For SumZ ?
E.SEL Econ ChangeOver Select
OA.E.C OA Enthalpy ChgOvr Selct
OA.EN Outdr.Enth Compare Value
OAT.L High OAT Lockout Temp
O.DEW OA Dewpoint Temp Limit
ORH.S Outside Air RH Sensor
E.TYP Economizer Control Type
EC.SW Economizer Switch Config
E.CFG ECON.OPERATION CONFIGS
E.P.GN Economizer Prop.Gain
E.RNG Economizer Range Adjust
E.SPD Economizer Speed Adjust
E.DBD Economizer Deadband
UEFC UNOCC.ECON.FREE COOLING
FC.CF Unoc Econ Free Cool Cfg
FC.TM Unoc Econ Free Cool Time
FC.L.O Un.Ec.Free Cool OAT Lock
Custom Psychrometric Curves — Refer to the psychrometric
chart and the standard Honeywell A-D curves in Fig. 10. The
curves start from the bottom and rise vertically, angle to the left
and then fold over. This corresponds to the limits imposed by
dry bulb changeover, outdoor enthalpy changeover and
outdoor dewpoint limiting respectively. Therefore, it is now
possible to create any curve desired with the addition of one
outdoor relative humidity sensor and the options for change-
over now available. See Fig. 11 for an example of a custom
curve constructed on a psychrometric chart.
UNOCCUPIED ECONOMIZER FREE COOLING — This
Free Cooling function is used to start the supply fan and use
the economizer to bring in outside air when the outside
temperature is cool enough to pre-cool the space. This is done
to delay the need for mechanical cooling when the system
enters the occupied period. This function requires the use of a
space temperature sensor.
When configured, the economizer will modulate during an
unoccupied period and attempt to maintain space temperature
Table 79 — Economizer Configuration Table
EXPANSION
Fig. 11 — Custom Changeover Curve Example
RANGE UNITS
Yes/No
0 - 100 %
0 - 100 %
Yes/No
0 - 3
1 - 5
18 - 28
-40 - 120 dF
50 - 62 dF
Enable/Disable
1 - 3
0 - 2
0.7 - 3.0
0.5 - 5 ^F
0.1 - 10
0.1 - 2 ^F
0-2
0 - 720 min
40 - 70 dF
to the occupied cooling set point. Once the need for cooling has
been satisfied during this cycle, the fan will be stopped.
Configuring the economizer for Unoccupied Economizer
Free Cooling is done in the UEFC group. There are three
configuration options, FC.CF, FC.TM and FC.LO.
Unoccupied Economizer Free Cooling Configuration
(FC.CF) — This option is used to configure the type of unoc-
cupied economizer free cooling control that is desired.
0 = disable unoccupied economizer free cooling
1 = perform unoccupied economizer free cooling as available
during the entire unoccupied period.
2 = perform unoccupied economizer free cooling as available,
FC.TM minutes before the next occupied period.
Unoccupied Economizer Free Cooling Time Configuration
(FC.TM) — This option is a configurable time period, prior to
the next occupied period, that the control will allow unoccu-
pied economizer free cooling to operate. This option is only
applicable when FC.CF = 2.
62
CCN POINT DEFAULT
ECON_ENA Yes
ECONOMIN 5
ECONOMAX 98
ECONTRIM Yes
ECON_SEL 0
OAEC_SEL 4
OAEN_CFG 24
OAT_LOCK 60
OADEWCFG 55
OARHSENS Disable
ECON_CTL 1
ECOSWCFG 0
EC_PGAIN 1
EC_RANGE 2.5
EC_SPEED 0.75
EC_DBAND 0.5
UEFC_CFG 0
UEFCTIME 120
UEFCNTLO 50
A48-7731