56
Table 33 —
Demand Limit Configuration
ECONOMIZER INTEGRATION WITH MECHANICAL
COOLING
When the economizer is able to provide free cooling (
Run Sta
-
tus
ECON
ACTV
= YES), mechanical cooling may be de
-
layed or even held off indefinitely.
NOTE: Once mechanical cooling has started, this delay logic is
no longer relevant.
Multi-Stage Cooling Economizer Mechanical Cooling Delay
This type of mechanical cooling delay is relevant to the follow
-
ing machine control types:
C.TYP
= 1
VAV-RAT
C.TYP
= 2
VAV-SPT
C.TYP
= 3
TSTAT-MULTI
C.TYP
= 4
SPT-MULTI
If the economizer is able to provide free cooling at the start of a
cooling session, the mechanical cooling algorithm (SumZ),
checks the economizer’s current position (
Run Status
ECON
ECn.P
) and compares it to the economizer’s maxi
-
mum position (
Configuration
ECON
EC.MX
) – 5%. Once
the economizer has opened beyond this point a 150 second timer
starts. If the economizer stays beyond this point for 2.5 minutes
continuously, the mechanical cooling algorithm is allowed to
start computing demand and stage compressors and unloaders.
ITEM
EXPANSION
RANGE
UNITS
CCN POINT
DEFAULT
DMD.L
DEMAND LIMIT CONFIG.
DM.L.S
Demand Limit Select
0 to 3
DMD_CTRL
0
D.L.20
Demand Limit at 20 mA
0 to 100
%
DMT20MA
100
SH.NM
Loadshed Group Number
0 to 99
SHED_NUM
0
SH.DL
Loadshed Demand Delta
0 to 60
%
SHED_DEL
0
SH.TM
Maximum Loadshed Time
0 to 120
min
SHED_TIM
60
D.L.S1
Demand Limit Sw.1 Setpt.
0 to 100
%
DLSWSP1
80
D.L.S2
Demand Limit Sw.2 Setpt.
0 to 100
%
DLSWSP2
50
Содержание WeatherExpert 48N2
Страница 135: ...135 Fig 18 48 50N Typical Power Schematic Nominal 075 Ton Unit Shown ...
Страница 136: ...136 Fig 19 48 50N Typical Power Schematic Nominal Ton 90 150 Units Shown ...
Страница 137: ...137 Fig 20 48 50N Main Base Board Input Output Connections ...
Страница 138: ...138 Fig 21 48 50N RXB EXB CEM Input Output Connections a48 9307 ...
Страница 139: ...139 Fig 22 48 50N EXV SCB Input Output Connections a48 9308 ...
Страница 140: ...140 Fig 23 48N Typical Modulating Gas Heat Unit Control Wiring ...
Страница 141: ...141 Fig 24 50N Typical Electric Heat Unit Control Wiring ...
Страница 144: ...144 Fig 27 48N Typical Gas Heat Section Wiring Nominal Ton 120 to 150 Units ...
Страница 145: ...145 Fig 28 48 50N Typical Power Component Control Wiring 460 v ...
Страница 146: ...146 Fig 29 48 50N Component Control Wiring 575 v Nominal Ton 075 to 150 Units ...
Страница 147: ...147 Fig 30 48 50N Component Arrangement Power Box ...
Страница 148: ...148 Fig 31 48 50N Component Arrangement Control Box ...
Страница 168: ...168 Fig 47 Sensor and Ignition Position Fig 48 Combustion Blower Details SENSOR DETAILS IGNITION DETAILS ...
Страница 240: ...240 APPENDIX D VFD INFORMATION CONT Fig G VFD Bypass Wiring Diagram WHEN USED ...