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The main and post filters use “Birth points” and current date to
calculate filter life and filter reminder. The birth date and cur
-
rent date are expressed as the number of days since 1/1/2000.
To change the main filter life, use
Configuration
FLTC
MF.LT
and set to required filter life from 1 to
60 months. To change the post filter life, use
Configuration
FLTC
PF.LT
and set to required filter life from 1 to
60 months.
To set main filter life reminder, use
Configura
-
tion
FLTC
MF.RM
and enter required filter reminder from
0 to 60 months. To set post filter life reminder, use
Configura
-
tion
FLTC
PF.RM
and enter required filter reminder from
0 to 60 months. Setting the reminder for either main or post fil
-
ter to 0 will disable the reminder function for that filter.
To reset the main filter status schedule, use
Configura
-
tion
FLTC
MF.RS
; when set to “yes”, the birth date for the
main filter will be converted to the current date in number of
days since 1/1/2000. To reset the post filter status schedule, use
Configuration
FLTC
PF.RS
; when set to “yes”, the birth
date for the post filter will be converted to the current date in
number of days since 1/1/2000.
3 = Delta Pressure
Main and post filter status can be determined in relation to a
maximum pressure differential across the corresponding filter.
The pressure difference is provided by a transducer and sen
-
sors. The delta pressure configuration is disabled in Service
Test mode and when the supply fan is not commanded on. If
the fan is on, the unit is not in test mode, and the filter delta
pressure is greater than or equal to the filter final resistance
(
MF_FR, PF_FR
) for a period of time equal to the status fault
timer (
FS.FT
), then an alarm will be generated. Recovery from
this alert is possible by clearing all alarms or by replacing the
dirty filter and the delta pressure is less than the new filter’s fi
-
nal resistance for more than 30 seconds.
4 = Predictive Life (Calculate and Learn)
The filter status can be determined through a predicted life.
When clean filters are first installed using this configuration
they must be commissioned before use. This is done by setting
the supply fan to a certain speed (in %) and measuring Supply
Air CFM (SACFM) versus delta pressure (
MF.DP
or
PF.DP
)
across the filter. There will need to be a maximum of 10 entries
plus an entry for 0 SACFM and one for maximum SACFM.
The data is collected and stored by the control.
The 10 entries are separated into bins based on maximum Sup
-
ply Air CFM (SACFM). Maximum SACFM is based on unit
size and supply fan SACFM configuration (SCFM_CFG). See
It is possible to reset the main filter predictive life table and the
post filter predictive life table separately. To reset the main fil
-
ter predictive life table use
Configuration
FLTC
MFT.R
and select yes. To reset the post filter predictive life table, use
Configuration
IAQ
FLTC
PFT.R
, and select yes.
5 = Predictive Life (Calculate only)
Once the control has learned the life of the filter it is possible to
set the control to use the learned information to calculate the
life of filters used in the future. This is only an option when the
replacement filters used are the same type and final resistance
as the filters used to learn the life.
During runtime the SACFM is used to interpolate the baseline
pressure. The interpolation is then used to calculate the filter
status. See Table 52.
Table 51 —
Maximum SACFM
Table 52 —
Dirty Filter Switch Points
Economizer
The N Series economizer damper is controlled by communicating
actuator motors over the local equipment network (LEN). The ac
-
tuator is connected directly to linkage in the economizer section.
Economizers are used to provide ventilation air as well as free
cooling based on several configuration options. This section
shall be devoted to a description of the economizer and its ability
to provide free cooling. Please see the section on Indoor Air
Quality for more information on setting up and using the econo
-
mizer to perform demand controlled ventilation (DCV) via the
controlling of its minimum position. Also, please see the Third
Party Control interface section for a description on how to take
over the operation of the economizer through external control.
The N Series controls have the capability to not only control an
economizer, but also to report its health and operation both to
the local display and CCN network. Also, through either the lo
-
cal display or the CCN, the service technician has access to ad
-
ditional diagnostic tools to predict the state of the economizer.
ECONOMIZER FAULT DETECTION AND DIAGNOSTICS
(FDD) CONTROL
The Economizer Fault Detection and Diagnostics control can
be divided into 2 tests: test for mechanically disconnected actu
-
ator and test for stuck/jammed actuator.
Mechanically Disconnected Actuator
The test for a mechanically disconnected actuator shall be per
-
formed by monitoring SAT as the actuator position changes
and the damper blades modulate. As the damper opens, it is ex
-
pected SAT will drop and approach OAT when the damper is at
100%. As the damper closes, it is expected SAT will rise and
approach RAT when the damper is at 0%. The basic test shall
be as follows:
1. With supply fan running, take a sample of SAT at current
actuator position.
2. Modulate actuator to new position.
3. Allow time for SAT to stabilize at new position.
4. Take sample of SAT at new actuator position and determine:
a. If damper has opened, SAT should have decreased.
b. If damper has closed, SAT should have increased.
5. Use current SAT and actuator position as samples for next
comparison after next actuator move.
UNIT SIZE
SCFM_CFG
MAX_SACFM
75, 90, 105
LOW FAN
40,000
120, 130, 150
LOW FAN
50,000
75, 90, 105, 120, 130, 150
HIGH FAN
60,000
ITEM
EXPANSION
RANGE
CCN
POINT
Configuration
FLTC
MFL.S
Main Filter Status
Configuration
0 - Disable
1 - Switch
2 - Schedule
3 - Delta Pressure
4 - Calculate and
Learn
5 - Calculate Only
FLTS_ENA
Configuration
FLTC
PFL.S
Post Filter Status
Configuration
0 - Disable
1 - Switch
2 - Schedule
3 - Delta Pressure
4 - Calculate and
Learn
5 - Calculate Only
PFLS_ENA
Inputs
GEN.I
FLT.S
Filter Status Input DRTY/CLN
FLTS
Inputs
GEN.I
PFL.S
Filter Status Input DRTY/CLN
PFLTS
Summary of Contents for WeatherExpert 48N2
Page 135: ...135 Fig 18 48 50N Typical Power Schematic Nominal 075 Ton Unit Shown ...
Page 136: ...136 Fig 19 48 50N Typical Power Schematic Nominal Ton 90 150 Units Shown ...
Page 137: ...137 Fig 20 48 50N Main Base Board Input Output Connections ...
Page 138: ...138 Fig 21 48 50N RXB EXB CEM Input Output Connections a48 9307 ...
Page 139: ...139 Fig 22 48 50N EXV SCB Input Output Connections a48 9308 ...
Page 140: ...140 Fig 23 48N Typical Modulating Gas Heat Unit Control Wiring ...
Page 141: ...141 Fig 24 50N Typical Electric Heat Unit Control Wiring ...
Page 144: ...144 Fig 27 48N Typical Gas Heat Section Wiring Nominal Ton 120 to 150 Units ...
Page 145: ...145 Fig 28 48 50N Typical Power Component Control Wiring 460 v ...
Page 146: ...146 Fig 29 48 50N Component Control Wiring 575 v Nominal Ton 075 to 150 Units ...
Page 147: ...147 Fig 30 48 50N Component Arrangement Power Box ...
Page 148: ...148 Fig 31 48 50N Component Arrangement Control Box ...
Page 240: ...240 APPENDIX D VFD INFORMATION CONT Fig G VFD Bypass Wiring Diagram WHEN USED ...