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ECL-PTU-207 Preloaded Applications
nviShedding (nviFP21)
This input is used to receive shedding information from a supervisory node.
Two types of shedding are available for the HVAC equipment.
The first type is a direct shedding of the electric heater. The electric heater is rescaled between 0%
and (100% - nviShedding). For example, if nviShedding = 40% and the electric heater demand is 65%,
the electric heater will be set to 39% (65% * (100% - 40%)).
The second type of shedding is an offset of the occupied/unoccupied setpoints. The shedding will au-
tomatically calculate an offset based on the difference between the occupied and standby setpoints to
apply to the effective setpoint.
For example, in Occupied mode:
£
EffectCoolSp = ((StbyCoolSp – OccCoolSp) * nviShedding/100) + OccCoolSp
£
EffectCoolSp = (( 26°C - 24°C) 30% / 100) + 24°C = 24.6°C
£
EffectHeatSp = ((StbyHeatSp – OccHeatSp) * nviShedding/100) + OccHeatSp
£
EffectHeatSp = (( 18°C - 20°C) 30% / 100) + 20°C = 19.4°C
For example, in Standby mode:
£
EffectCoolSp = ((StbyCoolSp – OccCoolSp) * nviShedding/100) + OccCoolSp
£
EffectCoolSp = (( 26°C - 24°C) 30% / 100) + 26°C = 26.6°C
£
EffectHeatSp = ((StbyHeatSp – OccHeatSp) * nviShedding/100) + OccHeatSp
£
EffectHeatSp = (( 18°C - 20°C) 30% / 100) + 18°C = 17.4°C
Shedding can be disabled using the variable nciMiscConfig/SheddingEnable (nviFP44).
To configure the system for shedding on setpoints, the variable nciMiscConfig/SheddingOnSetpoint
(nviFP44) must be set to True.
It is also possible to do shedding on lighting outputs. See the variable nviLightBlndCnfg (nviFP42) for
more information on this topic.
ID
Units
Valid Range
Default Value
nviFP21
SNVT_lev_percent (%)
0 to 100%
163,835%
Variables
