Frequency Converter Operation (Vfd) - Grundfos SL1 Instrucciones De Instalación Y Funcionamiento

8.6 IO 111
The IO 111 forms interface between a Grundfos sewage or
wastewater pump with analog and digital sensors and the pump
controller. The most important sensor data are indicated on the
front panel.
One pump can be connected to an IO 111.
Together with the sensors, the IO 111 forms a galvanic separation
between the motor voltage in the pump and the controller
connected.
IO 111 can distinguish between two categories of fault:
•Alarm: The pump stops. The fault is serious, such as too
high motor temperature.
•Warning: The pump does not stop. The fault is not serious,
such as too much water in the oil.
1 2
T1 T2 G1 A1 G2 A2 K1 K2 R1 R2
16
D1 D2 D3 D4 D5 D6 D7 D8
15
Reset
14
13
12
ON DIP
11
1 2 3 4 5 6 7 8 9 10
P1 P2 P3 P4 P5
10
Fig. 13 IO 111
Pos. Description
1 Terminal for alarm relay
2 Terminal for analog and digital inputs and outputs
3 Terminal for supply voltage (24 VAC/24 VDC)
Potentiometer for setting the warning limit of stator
4
insulation resistance
5 Terminal for RS485
Red indicator light. Alarm in case of too high motor
6
temperature.
Indicator lights for stator insulation resistance.
Green = ok.
7
Yellow = warning.
Red = alarm.
8 Indicator lights for measurement of water in oil
9 Terminal for measurement of stator insulation resistance
10 Terminal for connection of pump sensors
11 DIP switch for configuration
12 Green indicator light. On when the pump is running.
Red indicator light. On in case of moisture in the motor
13
(alarm).
14 Button for reset of alarm
15 Yellow indicator light. On in case of pump fault (warning).
16 Terminal for digital outputs
20
3
PE
4
A Y B
5
6
7
8
I1 I2 I3
9
Pos. Symbol Description
6 Stator temperature
7 Stator insulation resistance
8 Water in oil chamber
12 Pump running
13 Moisture in motor
15 Pump fault
8.6.1 Technical data
24 VAC - 10 %/+ 10 %, 50 and 60 Hz
Supply voltage:
24 VDC - 10 %/+ 10 %
Input current: Min. 0.5 A; max. 8 A
Power input: Max. 5 W
Ambient temperature: -13 °F to 149 °F (-25 °C to +65 °C)
Enclosure class: IP20
For further information, see installation and operating instructions
for IO 111.

8.7 Frequency converter operation (VFD)

In principle, all three-phase motors can be connected to a
frequency converter.
However, frequency converter operation will often expose the
motor insulation system to a heavier load and cause the motor to
be more noisy than usual due to harmonic frequency currents
caused by voltage peaks.
In addition, large motors driven via a frequency converter will be
loaded by bearing currents.
For frequency converter operation, please observe the following
information:
Requirements must be fulfilled.
Recommendations ought to be fulfilled.
Consequences should be considered.
8.7.1 Requirements
• The thermal protection of the motor must be connected.
• Peak voltage and dU/dt must be in accordance with the table
below. The values stated are maximum values supplied to the
motor terminals. The cable influence has not been taken into
account. See the frequency converter data sheet regarding the
actual values and the cable influence on the peak voltage and
dU/dt.
Maximum repetitive peak
voltage
(V)
850
• If the pump is an FM-approved pump, check if the FM
certificate of the specific pump allows the use of a frequency
converter.
• Set the frequency converter U/f ratio according to the motor data.
• Local regulations/standards must be fulfilled.
Maximum dU/dt
U 400 V
N
(V/μ sec.)
2000