Instruction manual

Cascade Controller Option
Description of choice:
Set the staging on time delay. A delay time
of 30 seconds (factory setting) is sufficient in
most systems. When encountering frequent
staging, decease delay time.
Quick Menu 025 Par. 716 Override bandwidth
(OVERRIDE BANDW%)
Value:
2 - 100 % (100 = OFF)
✭ 100 = OFF
Function:
When a large and quick change in the system demand
(such as a sudden water demand), the system pressure
rapidly changes and an immediate staging or destaging
of a fixed speed pump becomes necessary to match
the requirement. The override bandwidth (OBW) is
programmed to override the staging/destaging timer
for immediate response. The override bandwidth is a
percentage of the setpoint and defines the feedback
(pressure) at which the timers (set in parameters 714,
715) are overridden. For example, if the setpoint
is 5 bar and the override is set to 20%, the low
limit is 4 bar and the high limit 6 bar.
Description of choice:
The OBW must always be programmed to a higher
value than the staging bandwidth (SBW) set in
parameter 713. Setting the OBW too close to
the SBW could defeat the purpose with frequent
staging at momentary pressure changes. Setting
the OBW too high might lead to unacceptably
high or low pressure in the system while the SBW
timers are running. The value can be optimized
with increased familiarity with the system. See
parameter 717, Override Bandwidth Timer.
MG.60.I5.22 - VLT is a registered Danfoss trademark
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