Bell & Gossett 176R0649C Technologic 502 Series Pump Controller - Manual (Page 46)

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39-74 Low System Reset
Pressure
0.0 Depends on
P3965
0.0 If the pumps have been shut off due
to Low System Pressure and if the
pressure increases above this point
then the first pump will be turned on.
39-75 Low/High System Pressure
Source
- No function
- Analog input 53
- Analog input 54
- Analog input X30/11
- Analog input X30/12
0s 60s 0s This parameter tells the controller
which analog input is connected to the
System Pressure sensor. Input scaling
for the sensor is defined in parameter
group P06-xx.
39-76 Low System Pressure Alert
Level
- Warning
- Warning and Stop
Action to perform when the Low
System Pressure Proof Timer P39-
73 expires while the system pressure
remains below the value in P39-72.
39-8* No Flow
Shut
Down
39-80 No Flow Shut Down Proof
Time (Old Par. 776)
0s 9999s 0s If minimum speed, as set by parameter
P04-11 is reached, the timer set in this
parameter will activate. After the timer
expires, the minimum speed proof
timer, set in parameter P39-81 will
activate. After these timers expire, the
controller stops the pump and displays
WARNING, NO FLOW SHUT DOWN.
39-81 Minimum Speed Proof Time
(Old Par. 777)
0s 9999s 0s When only one pump is running at
minimum speed, the controller will
activate a sequence to stop the pump.
First the timer set in parameter P39-80
must expire. Then the timer set in this
parameter must expire. After these
timers expire, the controller stops the
pump. When the system pressure
drops below the value set in parameter
P39-82, the system will automatically
restart.
39-82 Restart Pressure Drop (Old
Par. 778)
0.0 PSI 999999.0 PSI 0.0 PSI
After the system has been shut down
by the No Flow Shut Down function,
it will automatically restart when the
pressure in the system drops below this
value. If this is set to OFF, the system
will not activate No Flow Shut Down.
Table 6-2. Parameter 39-** Group, Detailed Description (continued)