Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service, And Troubleshooting page 56

ITEM
DMD.L DEMAND LIMIT CONFIG.
DM.L.S Demand Limit Select
D.L.20 Demand Limit at 20 mA
SH.NM Loadshed Group Number
SH.DL Loadshed Demand Delta
SH.TM
Maximum Loadshed Time
D.L.S1 Demand Limit Sw.1 Setpt.
D.L.S2 Demand Limit Sw.2 Setpt.
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
Table 33 — Demand Limit Configuration
EXPANSION RANGE UNITS
0 to 3 DMD_CTRL
0 to 100 % DMT20MA
0 to 99 SHED_NUM
0 to 60 % SHED_DEL
0 to 120 min SHED_TIM
0 to 100 % DLSWSP1
0 to 100 % DLSWSP2
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.
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CCN POINT DEFAULT
0
100
0
0
60
80
50