Carrier WeatherExpert 48N2, Управление, пуск, эксплуатация, обслуживание и устранение неисправностей.

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Table 29 — Setpoints
Cool Mode Determination
If the machine control type ( Configuration  UNIT  C.TYP ) =
1 (VAV-RAT) or 2 (VAV-SPT) and the control is occupied ( Oper -
ating Modes  MODE  OCC =ON ), then the unit will not follow
the occupied cooling set point ( OCSP ). Instead, the control will
follow 2 offsets in the determination of an occupied VAV cooling
mode ( Setpoints  V.C.ON and Setpoints  V.C.OF ), applying
them to the low-heat off trip point and comparing the resulting
temperature to the controlling return temperature ( R.TMP ).
The Setpoints  V.C.ON (VAV cool mode on offset) and Set -
points  V.C.OF (VAV cool mode off offset) offsets are used in
conjunction with the low heat mode off trip point to determine
when to bring cooling on and off and in enforcing a true “vent”
mode between heating and cooling. See Fig. 4. The occupied cool -
ing set point is not used in the determination of the cool mode. The
occupied cooling set point is used for supply air reset only.
Fig. 4 — VAV Occupied Period Trip Logic
The advantage of this offset technique is that the control can
safely enforce a vent mode without worrying about crossing set
points. Even more importantly, under CCN linkage, the occu -
pied heating set point may drift up and down and as such this
technique of using offsets ensures a guaranteed separation in
degrees F between the calling out of a heating or cooling mode
at all times.
VAV Occupied Cool Mode Evaluation Configuration
There are VAV occupied cooling offsets under Setpoints .
NOTE: There is a submenu at the local display ( Run Status
 TRIP ) that allows the user to see the exact trip points for
both the heating and cooling modes without having to calculate
them. Refer to the Cool Mode Diagnostic Help section on
page 51 for more information.
To enter into a VAV Occupied Cool mode, the controlling tem -
perature must rise above
[
OHSP minus L.H.ON plus L.H.OF
plus V.C.ON
].
To exit out of a VAV Occupied Cool Mode, the controlling
temperature must fall below [ OHSP minus L.H.ON plus
L.H.OF plus V.C.ON minus V.C.OF ].
NOTE: With vent mode, it is possible to exit out of a cooling
mode during the occupied period if the return-air temperature
drops low enough. When supply-air temperature reset is not
configured, this capability will work to prevent over-cooling
the space during the occupied period.
Supply Air Set Point Control and the Staging of Compressors
Once the control has determined that a cooling mode is in ef -
fect, the cooling control point ( Run Status  VIEW  CL.C.P )
is calculated and is based upon the supply air set point ( Set -
points  SASP ) plus any supply air reset being applied ( In -
puts  RSET  SA.S.R ).
Refer to the SumZ Cooling Algorithm section on page 51 for a
discussion of how the N Series Comfort Link controls manage
the staging of compressors to maintain supply-air temperature.
EX.SL
EXV Init Pos Slope –100 to 100 EXV_SLP –0.4
EX.IN
EXV Init Pos Intercept –200 to 200 EXV_INT 66
EX.SM
EXV Smoothing Algorithm 0 to 1 EXV_SMAL 0
EX.EP
SH Error Exponent 1 to 1.5 ERR_POW 1.3
DP.OC
DP OVERRIDE CONFIGS
DP.RS
DP Rate of Change Set 2 to 15 °psig DP_RC_ST 10
DP.RC
DP Rate of Change Clr 0 to 5 °psig DP_RC_CL 1
DP.L1
DP Override Limit 1 400 to 450 psig DP_OD_L1 400
DP.L2
DP Override Limit 2 480 to 550 psig DP_OD_L2 500
DP.TO
DP Override Timeout 6 to 150 sec DP_OD_TO 90
DP.OR
DP Override Percent 0 to 15 % DP_OD_PT 10
ITEM EXPANSION RANGE UNITS CCN POINT DEFAULT
OHSP
Occupied Heat Setpoint 40-99 dF OHSP 68
OCSP Occupied Cool Setpoint 40-99 dF OCSP 75
UHSP Unoccupied Heat Setpoint 40-99 dF UHSP 55
UCSP Unoccupied Cool Setpoint 40-110 dF UCSP 90
GAP Heat-Cool Setpoint Gap 2-10 ^F HCSP_GAP 5
V.C.ON VAV Occ. Cool On Delta 0-25 ^F VAVOCON 3.5
V.C.OF VAV Occ. Cool Off Delta 1-25 ^F VAVOCOFF 2
SASP Supply Air Setpoint 45-75 dF SASP 55
SA.HI Supply Air Setpoint Hi 45-75 dF SASP_HI 55
SA.LO Supply Air Setpoint Lo 45-75 dF SASP_LO 60
SA.HT Heating Supply Air Setpt 90-145 dF SASPHEAT 85
T.PRG Tempering Purge SASP –20-80 dF TEMPPURG 50
T.CL Tempering in Cool SASP 5-75 dF TEMPCOOL 5
T.V.OC Tempering Vent Occ SASP –20-80 dF TEMPVOCC 65
T.V.UN Tempering Vent Unocc. SASP –20-80 dF TEMPVUNC 50
Table 28 — Cooling Configuration (cont)
ITEM EXPANSION RANGE UNITS CCN POINT DEFAULT
L.H.OF
DMDLHOFF
L.H.ON
DMDLHON
V.C. ON
VAVOCON
V.C. OF
VAVOCOFF
OH
S
P
a48-8414
ITEM EXPANSION RANGE UNITS
CCN
POINT
DEFAULT
V.C.ON
VAV Occ.
Cool On Delta
0 to 25 deltaF VAVOCON 3.5
V.C.OF
VAV Occ.
Cool Off Delta
1 to 25 deltaF VAVOCOFF 2