Wilo Wilo-Para /SC Series - Page 33

Installation and operating instructions Wilo-Para 33
en
Constant speed
(I, II, III)
Recommended for systems with fixed system resistance
requiring a constant volume flow.
The pump runs in three prescribed fixed speed stages (I,
II, III).
External control via a
iPWM signal
The required setpoint/actual value comparison for con-
trol is performed by an external controller.
A PWM signal (pulse-width modulation) is fed as a cor-
recting variable to the pump.
The PWM signal generator gives the pump a periodic
sequence of impulses (the duty cycle) in accordance
with DIN IEC 60469-1.
iPWM 1 mode (heating application):
In iPWM 1 mode, the pump speed is controlled according
to the PWM input signal.
Behaviour in the event of a cable break:
If the signal cable is separated from the pump, e.g. due
to a cable break, the pump accelerates to maximum
speed.
PWM signal input [%]
< 5: Pump runs at maximum speed
5-85: The speed of the pump decreases linearly from
n
max
to n
min
85-93: Pump runs at minimum speed (operation)
85-88: Pump runs at minimum speed (starting)
93-100: Pump stops (standby)
I
III
II
H/m
Q/m³/ h
NOTICE
Factory setting:
Constant speed, pump curve III
55 (45)%
45 (55)%
5 (95)%
65 (35)%
35 (65)%
75 (25)%
85 (15)%
15 (85)%
25 (75)%
H/m
Q/m³/ h
% PWM 1 (% PWM 2)
3:0
max
n
¹/min
min
0 5 85 88
93 100
PWM
%