75
T24 Econ Move SAT Change (S.CHG)
The minimum amount (in degrees F) SAT is expected to
change based on economizer position change of T24ECSTS
with a range of 0 to 5. Default is 0.2.
T24 Econ RAT-OAT Diff (E.SOD)
The minimum difference (in degrees F) between RAT (if avail-
able) or SAT (with economizer closed and fan on) and OAT to
perform mechanically disconnected actuator testing with a
range of 5 to 20. Default is 15.
T24 Heat/Cool End Delay (E.CHD)
The amount of time (in minutes) to wait after mechanical cool-
ing or heating has ended before testing for mechanically dis-
connected actuator. This is to allow SAT to stabilize at conclu-
sion of mechanical cooling or heating. The range is 0 to 60; de-
fault is 25.
SAT Settling Time (SAT.T)
SAT_SET/2 is the amount of time (in seconds) economizer re-
ported position must remain unchanged (±
EC.MD
) before the
control will attempt to detect a mechanically disconnected ac-
tuator. This is to allow SAT to stabilize at the current econo-
mizer position. This configuration sets the settling time of the
supply-air temperature (SAT). This typically tells the control
how long to wait after a stage change before trusting the SAT
reading, and has been reused for Title 24 purposes. The range
is 10 to 900; default is 240.
T24 Test Minimum Position (ET.MN)
Minimum position below which tests for a mechanically dis-
connected actuator will not be performed. For example, if the
actuator moves entirely within the range 0 to
ET.MN,
a deter-
mination of whether the actuator is mechanically disconnected
will not be made. This is due to the fact that at the extreme
ends of the actuator movement, a change in position may not
result in a detectable change in temperature. When the actuator
stops in the range 0 to 2% (the actuator is considered to be
closed), a test will be performed where SAT is expected to be
approximately equal to RAT. If SAT is not determined to be ap-
proximately equal to RAT, a “damper not modulating” alert
will be logged. Range is 0 to 50; default is 15.
T24 Test Maximum Position (ET.MX)
Maximum position above which tests for a mechanically dis-
connected actuator will not be performed. For example, if the
actuator moves entirely within the range
ET.MX
to 100, a de-
termination of whether the actuator is mechanically discon-
nected will not be made. This is due to the fact that at the ex-
treme ends of the actuator movement, a change in position may
not result in a detectable change in temperature. When the ac-
tuator stops in the range 98 to 100% (the actuator is considered
to be open), a test will be performed where SAT is expected to
be approximately equal to OAT. If SAT is not determined to be
approximately equal to OAT, a “damper not modulating” alert
will be logged. Range is 50 to 100; default is 85.
Economizer Deadband Temp (AC.EC)
The allowed deadband between measured SAT and calculated
SAT when performing economizer self-test. Range is 0 to 10;
default is 4.
Econ Fault Detect Gap (E.GAP)
The discrepancy between actuator command and reported posi-
tion in percentage. Used to detect actuator stuck/jammed.
Range is 2 to 100; default is 5.
Econ Fault Detect Timer (E.TMR)
The timer for actuator fault detection in seconds. Used to de-
tect actuator stuck/jammed. Range is 10 to 240; default is 20.
Excess Air CFM (X.CFM)
The max allowed excess air in CFM. Used to detect excess out-
side air. Range is 400 to 4000; default is 800.
Excess Air Detect Timer (X.TMR)
The timer for excess air detection with a range of 30 to 240.
Default is 150.
Econ Auto-Test Day (EC.DY)
The day on which to perform automatic economizer test.
Range=NEVER, MON, TUE, WED, THR, FRI, SAT, SUN.
Default is SAT.
Econ Auto-Test Time (EC.TM)
The time at which to perform automatic economizer test. The
range is 0 to 23; default is 2.
T24 AutoTest SF Run Time (AC.MR)
Amount of time to run supply fan before sampling torque or
making torque comparison. Range is 1 to 10; default is 2.
T24 Auto-Test VFD Speed (AC.SP)
Speed to run VFD during economizer auto-component test.
Range is 10 to 50; default is 20.
T24 Auto-Test Econ% Opn (AC.OP)
Amount to open each economizer during auto-component test.
Range is 1 to 100. Default is 50.
T24 Auto-Test VFD% Chng (VF.PC)
Expected change in torque when damper opens from 0 to
AC.OP
and then from
AC.OP
to 0. Range is 1 to 20; default is 10.
SETTING UP THE SYSTEM
The economizer configuration options are under the Local Dis-
play Mode
Configuration
ECON
.
See Table 64.
Economizer Installed? (EC.EN)
If an economizer is not installed or is to be completely dis-
abled, the configuration option
EC.EN
may be set to No. Oth-
erwise, in the case of an installed economizer, this option must
be set to Yes.
Economizer Actuator 2 Installed? (EC2.E)
For 48/50P055-100 units, a second economizer actuator is re-
quired. For sizes 055-100, set this configuration to Yes.
Economizer Minimum Position (EC.MN)
The configuration option
EC.MN
is the economizer minimum
position. See the section on indoor air quality for further infor-
mation on how to reset the economizer further to gain energy
savings and to more carefully monitor IAQ problems.
Economizer Maximum Position (EC.MX)
The upper limit of the economizer may be limited by setting
EC.MX
. It defaults to 98% to avoid problems associated with
slight changes in the economizer damper’s end stop over time.
Typically, this will not need to be adjusted.
Economizer Trim for Sum Z? (E.TRM)
Sum Z is the adaptive cooling control algorithm used for multi-
ple stages of mechanical cooling capacity. The configuration
option
E.TRM
is typically set to Yes, and allows the economiz-
er to modulate to the same control point (Sum Z) that is used to
control capacity staging. The advantage is lower compressor
cycling coupled with tighter temperature control. Setting this
option to No will cause the economizer, if it is able to provide
free cooling, to open to the Economizer Max. Position
(
EC.MX
) during mechanical cooling.
Summary of Contents for Weathermaster 48P2030-100
Page 130: ...130 Fig 19 Typical Power Schematic Sizes 040 075 Shown ...
Page 131: ...131 Fig 20 Main Base Board Input Output Connections ...
Page 132: ...132 Fig 21 RXB EXB CEM SCB Input Output Connections ...
Page 133: ...133 Fig 22 Typical Gas Heat Unit Control Wiring 48P030 100 Units Shown ...
Page 134: ...134 Fig 23 Typical Electric Heat Wiring 50P030 100 Units Shown ...
Page 135: ...135 Fig 24 Typical Power Wiring 115 V ...
Page 136: ...136 Fig 25 Typical Gas Heat Section Size 030 050 Units Shown ...
Page 138: ...138 Fig 27 Component Arrangement Size 030 035 Units ...
Page 139: ...139 Fig 28 Component Arrangement Size 040 075 Units ...
Page 140: ...140 Fig 29 Component Arrangement Size 090 100 Units ...