Load Shedding Options - Lennox PRODIGY2.0 Application Manual

19. Load Shedding Options

The M3 unit controller may be setup to de-energize part or all of the mechanical cooling provided by a rooftop unit.
Configuration ID 2, position 8 defines where the digital input for load shedding is configured.
Go to SETUP > INSTALL > Configuration ID 2, position 8 will need to be set to one of the following options:
•
N - NOT INSTALLED
•
G - GLOBAL INPUT (A55-P297-9)
•
2 - DI-2 (DIGITAL INPUT 2 - A55 - P299 - 4)
•
3 - DI-3 (DIGITIAL INPUT 3 - A55 - P299 - 6)
NOTE: When options 2 or 3 are enabled on either DI-2 or DI-3, these inputs cannot not be shared with any other devices
(i.e, global, blower overload or drain pan overflow). Similarly option G (Global input) may be used only if economizer
global mode is not enabled.
Parameter 194 - select 0 - 4. This parameter defines how many compressors are turned off when load shedding is active
(i.e., digital input ON; contact closed).
Control Parameter
No Screen Name
194 LOAD SHED NUM COMP
Table 51. M3 Load Shedding Options
Control Value
Parameter
Short
Description Min.
Number of com­
pressors to
0
shed during
load shedding
Max
.
Default
Units
0 4 Option
78
Description
Number of compressors to be
turned off when load shedding is
active.
For 2-stage A box compressor, a
value of one shuts off 2nd stage
only and a value of 2 turns com­
pressor completely off.