80
4 12 Pump Control
4 12 Pump Control
The Pump Control function is one of the most unique features of the
-
. Using this function the pressure in a process can be controlled to meet
strict demands. The pressure in a process is commonly generated by a pump
driven by a variable speed motor. This type of system has the following
which affects the control’s behavior:
The system is very
noisy.
The pressure is changed very rapidly.
Pump characteristics are
ultra nonlinear with respect to speed.
The pump can't generate any more
pressure as its speed is lower than half of its rated speed.
An ordinary
pump may slowly lose pressure even if valves are completely closed.
Normally, a pump will not generate additional pressure at speeds lower than
half of rated speed.
ETR
8300
characteristics
1:
2:
3:
4:
5:
The Pump Control function is one of the most unique features of the
-
. Using this function the pressure in a process can be controlled to meet
strict demands. The pressure in a process is commonly generated by a pump
driven by a variable speed motor. This type of system has the following
which affects the control’s behavior:
The system is very
noisy.
The pressure is changed very rapidly.
Pump characteristics are
ultra nonlinear with respect to speed.
The pump can't generate any more
pressure as its speed is lower than half of its rated speed.
An ordinary
pump may slowly lose pressure even if valves are completely closed.
Normally, a pump will not generate additional pressure at speeds lower than
half of rated speed.
ETR
8300
characteristics
1:
2:
3:
4:
5:
A conventional controller can't fulfill the conditions mentioned above. Only the
superior noise rejection capability in addition to the fast sampling rate
provided by the ETR-8300 can realize such an application. To achieve this, set
the following parameters in the setup menu:
A conventional controller can't fulfill the conditions mentioned above. Only the
superior noise rejection capability in addition to the fast sampling rate
provided by the ETR-8300 can realize such an application. To achieve this, set
the following parameters in the setup menu:
FUNC=FULL
EIFN=NONE
PVMD=PV1
FILT=0.5
SELF=NONE
SPMD=PUMP
SP2F=DEVI
FUNC=FULL
EIFN=NONE
PVMD=PV1
FILT=0.5
SELF=NONE
SPMD=PUMP
SP2F=DEVI
Key menu
Key menu
SPMD
SP2F
REFC
SP2
SPMD
SP2F
REFC
SP2
and program the following parameters in the user menu:
and program the following parameters in the user menu:
REFC= Reference constant
SP2= A negative value is added to SP1 to obtain the set point for idle
state
REFC= Reference constant
SP2= A negative value is added to SP1 to obtain the set point for idle
state
Since a pump can't produce additional pressure at lower speeds, the pump
may not stop running even if the pressure has reached the set point. If this
happens, the pump will be over worn out and waste additional power. To avoid
this, the
-
provides a
in the user menu. If
PUMP is selected for SPMD, the controller will periodically test the process by
using this reference constant after the pressure has reached its set point.
If the test shows that
the pressure is not consumed by the process, the controller will gradually
decrease the power to the pump until the pump stops running. As this
happens, the controller enters
. The idle state will use a lower set
point which is obtained by adding SP2 to SP1 until the pressure falls below
this set point. The idle state is provided for the purpose of preventing the
pump from been restarted too frequently. The value of SP2 should be
to ensure a correct function.
ETR 8300
Reference Constant REFC
idle state
negative
If the
test shows that the pressure is still consumed by the process, the controller
will continue to supply appropriate power to the pump.
Since a pump can't produce additional pressure at lower speeds, the pump
may not stop running even if the pressure has reached the set point. If this
happens, the pump will be over worn out and waste additional power. To avoid
this, the
-
provides a
in the user menu. If
PUMP is selected for SPMD, the controller will periodically test the process by
using this reference constant after the pressure has reached its set point.
If the test shows that
the pressure is not consumed by the process, the controller will gradually
decrease the power to the pump until the pump stops running. As this
happens, the controller enters
. The idle state will use a lower set
point which is obtained by adding SP2 to SP1 until the pressure falls below
this set point. The idle state is provided for the purpose of preventing the
pump from been restarted too frequently. The value of SP2 should be
to ensure a correct function.
ETR 8300
Reference Constant REFC
idle state
negative
If the
test shows that the pressure is still consumed by the process, the controller
will continue to supply appropriate power to the pump.
The pump functions are summarized as follows:
1. If the process is demanding material ( ie. Lost pressure ), the controller
will precisely control the pressure at set point.
2. If the process no longer consumes material, the controller will shut off the
pump as long as possible.
3. The controller will restart the pump to control the pressure at set point as
soon as the material is demanded again while the pressure falls below a
predetermined value ( ie. SP1+SP2 ).
The pump functions are summarized as follows:
1. If the process is demanding material ( ie. Lost pressure ), the controller
will precisely control the pressure at set point.
2. If the process no longer consumes material, the controller will shut off the
pump as long as possible.
3. The controller will restart the pump to control the pressure at set point as
soon as the material is demanded again while the pressure falls below a
predetermined value ( ie. SP1+SP2 ).
Pump Control Features:
Pump Control Features:
1. Minimum oscillation of pressure
2. Rapidly stabilized
3. Guaranteed pump stop
4. Programmable pump stopping
interval
1. Minimum oscillation of pressure
2. Rapidly stabilized
3. Guaranteed pump stop
4. Programmable pump stopping
interval
PUMP: A Cost Effective
yet Perfect Solution
PUMP: A Cost Effective
yet Perfect Solution
