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

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Static Pressure Reset Limit (SP.LM)
This option defines the maximum amount of static pressure re-
set that is allowed. This is sometimes called a “clamp.”
NOTE: Resetting static pressure via RAT and SPT is primarily a
constant volume application which utilizes a VFD. The reasoning
is that there is significant energy savings in slowing down a supply
fan as opposed to running full speed with supply air reset. Main-
taining the supply air set point and slowing down the fan has the
additional benefit of working around dehumidification concerns.
Static Pressure Reset Economizer Position (SP.EC)
This option effectively resets ECONOMIN to fully occupied
ventilation position, to account for the drop in static pressure
during static pressure reset control. The static pressure reset for
the calculation cannot be larger than the supply air static set
point ( SP.SP ).
The calculation is as follows:
(Static Pressure Reset/
SP.SP ) x (ECONOSPR – ECONOMIN)
As an example, the static pressure set point ( SP.SP ) = 1.5 in. wg.
The current static pressure reset is set to 0.5 in. wg. The settings
for ECONOSPR = 50% and ECONOMIN = 20%.
Therefore, the amount to add to the economizer’s ECONOMIN
configuration is: (0.5/1.5) x (50-20) = 10%. In effect, for the
positioning of the economizer, ECONOMIN would now be re-
placed by EC 10%.
Static Pressure PID Config (S.PID)
Static pressure PID configuration can be accessed under this
heading in the Configuration

SP submenu. Under most oper-
ating conditions, the control PID factors will not require any
adjustment and the factory defaults should be used. If per-
sistent static pressure fluctuations are detected, small changes
to these factors may improve performance. Decreasing the fac-
tors generally reduces the responsiveness of the control loop,
while increasing the factors increases its responsiveness. Note
the existing settings before making changes, and seek technical
assistance from Carrier before making significant changes to
these factors.
Static Pressure PID Run Rate
(S.PID

SP.TM)
This is the number of seconds between duct static pressure read-
ings taken by the Comfort Link PID routine.
Static Pressure Proportional Gain (S.PID

SP.P)
This is the proportional gain for the static pressure control PID
control loop.
Static Pressure Integral Gain
(S.PID

SP.I)
This is the integral gain for the static pressure control PID con-
trol loop.
Static Pressure Derivative Gain
(S.PID

SP.D)
This is the derivative gain for the static pressure control PID
control loop.
STATIC PRESSURE RESET
The configuration for Static Pressure Reset is found under
Configuration

SP .
Static Pressure Reset Sensor
If the outdoor air quality sensor is not configured ( Configura-
tion

IAQ

AQ.CF

OQ.A.C =0), then it is possible to use the
outdoor air quality sensor location on the CEM board to perform
static pressure reset via an external 4 to 20 mA input. Enabling this
sensor will give the user the ability to reset from 0 to 3-in. wg of
static pressure. The reset will apply to the supply static pressure set
point ( Configuration

SP

SP.SP ), where 4 mA = 0-in. wg and
20 mA = 3-in. wg.
As an example, the static pressure reset input is measuring 6 mA,
and the input is resetting 2 mA of its 16 mA control range. The 4
to 20 mA range corresponds directly to the 0 to 3 in. wg of reset.
Therefore, 2 mA reset is 2 /
16
* 3-in. wg = 0.375-in. wg of reset. If
the static pressure set point ( SP.SP ) = 1.5-in. wg, then the static
pressure control point for the system will be reset 1.5 – 0.375 =
1.125-in. wg.
For third party 4 to 20 mA SP reset, wire the input to TB202
terminals 6 and 7.
For reset via a connected ComfortID™ system, the Linkage
Coordinator terminal monitors the primary-air damper position
of all the terminals in the system. It then calculates the amount
of supply static pressure reduction necessary to cause the most
open damper in the system to open more than the minimum
value (60%) but not more than the maximum value (90% or
negligible static pressure drop). This is a dynamic calculation,
which occurs every two minutes whenever the system is oper-
ating. It ensures that the supply static is sufficient to supply the
required airflow at the worst case terminal but not more than
necessary, so that the air terminals do not have to operate with
a pressure drop greater than required to maintain the airflow set
point of each individual terminal in the system. As the system
operates, if the most open damper opens more than 90%, the
system recalculates the pressure reduction variable and Con-
figuration

SP

SP.RS , the amount of reset, is reduced. If the
most open damper closes to less than 60%, the system recalcu-
lates the pressure reduction variable and SP.RS is increased.
With this system, one needs to enter as the static pressure set
point SP.SP either a maximum duct design pressure or maxi-
mum equipment pressure, whichever is less. The system will
determine the actual set point required and deliver the required
airflow to every terminal under the current load conditions. As
the conditions and airflow requirements at each terminal
change throughout the operating period, so will SP.RS and the
unit’s effective static pressure set point.
In the unlikely chance that both static pressure reset control
signals are simultaneously present, the CCN signal will take
precedence.
RELATED POINTS
These points represent static pressure control and static pres-
sure reset inputs and outputs. See Table 60.
Table 60 — Static Pressure Reset Related Points
ITEM EXPANSION RANGE CCN POINT DEFAULT
SP.RS Static Press. Reset Sensor Enable/Disable SPRSTSEN Disable
ITEM EXPANSION RANGE UNITS CCN POINT DEFAULT
Inputs

4-20

SP.M Static Pressure mA 4 to 20 mA SP_MA

4-20

SP.M.T Static Pressure mA Trim -2.0 to +2.0 mA SPMATRIM

4-20

SP.R.M Static Pressure Reset mA 4 to 20 mA SPRST_MA 0.0

RSET

SP.RS Static Pressure Reset 0.0 to 3.0 in. wg SPRESET 0.0
Outputs

FANS

S.VFD Supply Fan VFD Speed 0 to 100 % SFAN_VFD