Daikin WGZ030DW Operating And Maintenance Manual page 48

Network Limit
The maximum unit capacity can be limited by a network signal. This function is only enabled if the unit
control source is set to network. The maximum unit capacity stage is based on the network limit value
received from the BAS, and is determined as shown in the following graph.
Network Limit vs. Max Stage
(with 4 compressors)
4
3
Max
Stage
2
1
0
0 25.0
Network Limit (%)
In order to allow all stages to run, a signal of 100.0% is required.
Maximum LWT Rate
The maximum rate at which the leaving water temperature can drop is limited by the Maximum Pull
Down Rate set point when the unit mode is cool. If the rate exceeds this set point, no more compressors
shall be started until the pull down rate is less than the set point. Running compressors will not be
stopped as a result of exceeding the maximum pull down rate.
Low Ambient Lockout (Water Cooled = NO Only)
If the OAT drops below the low ambient lockout set point, then all running circuits will do a normal stop,
after the compressors have stopped the evaporator water pump will stop. Once the lockout has been
triggered, the evaporator water pump will remain off and no compressors will start until the OAT rises to
the lockout set point plus 5°F.
Manual Compressor Control
The operator can manually enable and disable individual compressors. When a compressor has been
disabled it is considered unavailable to start in the staging logic. With Manual Compressor control it is
possible to take a damaged compressor offline while the remaining compressors on the circuit can still
provide some cooling.
A running compressor cannot be disabled until it has been shutdown. If both of the compressors on a
circuit have been disabled then the circuit is disabled. If both circuits have all of their compressors
disabled, the Unit state will remain "Off".
Normal Circuit Shutdown
If a condition arises that requires a circuit to shut down, but it is not an emergency situation, then the
circuit will do a pump down. A normal circuit shutdown will be initiated when any of the following
occur:
•
Unit State = Pump Down
•
Circuit Switch = Off
•
Low Ambient Lockout
48
50.0 75.0 100.0
WGZ030D through WGZ200D
Network Limit vs. Max Stage
(with 6 compressors)
6
5
4
Max
Stage
3
2
1
0
0 16.7 33.3 50.0
Network Limit (%)
66.7 83.4 100.0
OMM 1130-2