Carrier Weathermaster 48P2030-100, Управление, пуск, эксплуатация, обслуживание и устранение неисправностей.

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the outside air temperature will be compared to the return-air
temperature to disallow free cooling as shown in Table 63.
Table 63 — Differential Dry Bulb Cutoff Control
The status of differential dry bulb cutoff will be visible under
Run Status

ECON

DISA

DDBC .
There will be hysteresis where OAT must fall 1°F lower
than the comparison temperature when transitioning from
DDBCSTAT=YES to DDBSTAT=NO.
ECONOMIZER SELF-TEST
The unit has some configurations with two actuators (when
ECON_TWO=YES). Because it is possible for one actuator to
become mechanically disconnected while the other(s) continue
to work properly, the following self-test utilizes fan character-
istics and motor power measurements to determine whether the
dampers are properly modulating. A fan that is moving more
air uses more power than a fan that is moving a lesser quantity
of air. In this test, each actuator/damper assembly is command-
ed independently while the fan and motor characteristics are
monitored.
It is possible to manually start the self-test:
• In Navigator, this test will be located at Service Test

FANS

E.TST .
• Running the test will require setting Service Test

TEST =ON.
The test will also automatically run based on EC.DY and
EC.TM :
• If conditions are acceptable to run the self-test (see below),
the test will be automatically started on the configured day
EC.DY at the configured time EC.TM .
• If conditions are not acceptable to run the self-test, it will
be re-scheduled for 24 hours later.
The economizer self-test will only be allowed to run if all of
the following conditions are valid:
1. The economizer is enabled.
2. The second economizer actuator is enabled.
3. No actuators are detected as stuck.
4. No actuators are detected as unavailable.
5. RCB1 is properly communicating.
6. The unit is not down due to failure (A152).
7. The unit has a supply fan VFD and the fan is not in bypass
mode.
8. If configured for building pressure, the unit has an return
fan VFD and the fan is not in bypass mode.
In addition to the above conditions, the economizer self-test
will not be automatically run if any of the following conditions
are valid:
1. Unit not in OFF or VENT mode.
The Test screen should be similar to the following:
EC.TR ON
EC.DT WAITING
S.VFD 20.0%
TORQ 17.5%
ECN.P 20%
EC2.P 0%
EC3.P 0%
EC.ST RUNNING
Setting EC.TS =ON will perform the following:
1. Command all actuators and dampers to the closed position.
2. Run the fan at T24SFSPD for T24ACMRT minutes and
take a baseline torque (VFD1TMAV) measurement. With
the dampers closed, there will be the least amount of air-
flow, and therefore the least amount of motor torque.
3. Modulate a single actuator/damper assembly open to
T24ACOPN. This will increase the airflow.
4. Let the motor run for one minute. If the torque has
increased by VF.PC % over the baseline measurement
from step 2, the current torque is set as the new baseline
measurement and proceed to Step 5. If the torque has not
increased by
VF.PC %, continue to run the fan for a total of
AC.MR minutes. If, after AC.MR minutes total, the torque
has not increased by VF.PC % over the Step 2 baseline
measurement, a fault is logged, and the test is ended.
5. Modulate the actuator/damper assembly closed.
6. Let the motor run for one minute. If the torque has
decreased by VF.PC % over the baseline measurement
from step 4, the current torque is set as the new baseline
measurement; proceed to Step 7. If the torque has not
decreased by
VF.PC %, continue to run the fan for a total
of AC.MR minutes. If, after AC.MR minutes total, the
torque has not decreased by VF.PC % below the Step 4
baseline measurement, a fault is logged, and the test is
ended.
7. Repeat Steps 1-5 for each additional actuator/damper
assembly.
8. Command actuators/dampers to “normal” positions.
If the torque increases and decreases properly,
EC.ST ="PASS,"
otherwise EC.ST ="FAIL".
If EC.ST is set to pass, any existing “damper not modulating”
alert will be automatically cleared.
If
EC.ST is set to fail, the “damper not modulating” alert will
be logged.
If at any point in the test the fan does not reach the command
speed or an actuator does not reach the command position
within five minutes, the test will be stopped and the status set
to “NOT RUN.”
FAULT DETECTION DIAGNOSTIC CONFIGURATION
POINTS
Log Title 24 Faults (LOG.F)
Defines when Title 24 mechanically disconnected actuator
faults should be logged. When set to YES, it will attempt to de-
tect and log mechanically disconnected actuator. When set to
NO, it will not attempt to detect and log mechanically discon-
nected actuator. Default is NO.
T24 Econ Move Detect (EC.MD)
The amount of change required in economizer reported posi-
tion before economizer is detected as moving. The range is be-
tween 1 and 10. Default is 1.
T24 Econ Move SAT Test (EC.ST)
The minimum amount economizer must move in order to trig-
ger the test for a change in SAT; i.e., the economizer must
move at least T24ECSTS% before the control will attempt to
determine whether the actuator is mechanically disconnected.
The range is between 10 and 20. Default is 10.
E.SEL (ECON_SEL)
DDB.C
(EC_DDBCO)
OAT/RAT
Comparison
DDBC
(DDBCSTAT)
NONE,
OUTDR.ENTH,
DIF.ENTHALPY N/A N/A NO
DIFF.DRY BULB
0°F OAT>RAT YES
OAT

RAT NO
–2°F OAT>RAT–2 YES
OAT

RAT–2 NO
–4°F OAT>RAT–4 YES
OAT

RAT–4 NO
–6°F OAT>RAT–6 YES
OAT

RAT–6 NO