Grundfos ALPHA1 L Serie Instrucciones De Instalación Y Funcionamiento página 17

6.3.2 PWM input signal profile A (heating)
The pump runs on constant-speed curves depending on the PWM
input signal. The speed decreases when the PWM value increases.
If the PWM signal equals zero (0 VDC), the pump will switch to the
control mode selected before connecting to a PWM signal.
A
C
PWM input signal profile A (heating)
Pos. Description
A Max.
B PWM input signal
C Speed
PWM input signal [%] Pump status
≤ 10 Maximum speed: max.
> 10 / ≤ 84 Variable speed: min. to max.
> 84 / ≤ 91 Minimum speed: IN
> 91/95 Hysteresis area: on/off
> 95 or ≤ 100 Standby mode: off
6.3.3 PWM feedback signal
The PWM feedback signal offers pump information like in bus
systems:
• current power consumption (accuracy ± 2 % of PWM signal)
• warning
• alarm.
Alarms
Alarm output signals are available because some PWM output
signals are dedicated to alarm information. If a supply voltage is
measured below the specified supply voltage range, the output
signal is set to 75 %. If the rotor is locked due to deposits in the
hydraulics, the output signal is set to 90 % because this alarm has a
higher priority. See fig. PWM feedback signal - power consumption.
100
2
3
90
4
80
5
70
60
50
7
40
30
20
10
25 50 100 150
PWM feedback signal - power consumption
B
6
1
200 250
Pos. Description
1 Power [W]
2 Standby (stop)
3 Alarm stop: fault, blocked pump
4 Alarm stop: electrical fault
5 Warning
6 Saturation at 70 Watt
7 Slope: 1 W / % PWM
Data
Maximum rating
PWM frequency input with high-speed
optocoupler
Guaranteed standby power consumption
Rated input voltage - high level
Rated input voltage - low level
High-level input current
Input duty cycle
PWM frequency output, open collector
Accuracy of output signal regarding
power consumption
Output duty cycle
Collector emitter breakdown voltage on
output transistor
Collector current on output transistor
Maximum power dissipation on output
resistor
Zener diode working voltage
Maximum power dissipation in Zener di-
ode
Symbol Value
f 100-4000 Hz
< 1 W
U
4-24 V
iH
U
< 1 V
iL
I
< 10 mA
iH
PWM 0-100 %
f 75 Hz ± 5 %
± 2 % (of
-
PWM signal)
PWM 0-100 %
U
< 70 V
c
I
< 50 mA
c
P
125 mW
R
U
36 V
z
P
300 mW
z
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