Danfoss ECL Comfort 310 Operating Manual page 66

Operating Guide ECL Comfort 310, application P318
Speed control of pumps, in general
0 – 10 Volt (0 – 100 %) as control signal
Typically, the pump speed will be 100 % at 10 Volt. When lowering
the control voltage, the pump speed falls. Depending on pump
type, the lowest pump speed can be 20 – 30 %. If the control signal
gets lower than 2 – 3 Volt, the pump remains on "lowest pump
speed". The pump will be switched OFF if the applied voltage gets
lower than 1 Volt. The pump will be switched ON again when the
control signal gets higher than 3 Volt.
PWM % as control signal
Typically, the pump speed will be 100 % at PWM value = 100 %.
When lowering the PWM value, the pump speed falls. Depending
on pump type, the lowest pump speed can be 10 - 15 %. If the
control signal gets lower than 10 – 15 %, the pump remains on
"lowest pump speed". The pump will be switched OFF if the applied
PWM value gets lower than 10 %. The pump will be switched ON
again when the control signal gets higher than 15 %.
Dimensioning:
When dimensioning the installation, the pump characteristics must
be considered in order to achieve an acceptable temperature
control.
Speed control of control pump (primary control pump)
The control pump P1 / V1 can be speed controlled by means of a
0 -10 volt signal or a PWM (Pulse Width Modulation) signal. The
speed control signal, as 0 - 10 V, comes from the "Analog Out 1"
(terminals 59 and 62) on the ECA 32 or 35 module.
The speed control signal, as PWM, comes from the output "PWM
Out 1" (terminals 52 and 49) on the ECA 35 module.
The desired temperature at S3 is basis for the speed control
procedure.
The control voltage / PWM is expressed as a % value and displayed
at the V1 symbol.
When the S3 temperature gets lower than the desired temperature,
the control voltage / PWM is gradually increased in order to increase
the speed of the control pump more than the moment before. By
this, the S3 temperature aligns with the desired temperature.
The control voltage / PWM remain on a stable value as long as the
S3 temperature corresponds to the desired temperature.
The control voltage / PWM can be limited to a maximum and a
minimum % value.
Furthermore, the control signal can be reversed; this means the
higher the % value, the lower the speed.
Danfoss District Energy
66 DEN-SMT/DK VI.JM.Q3.02