Grant Vortex Eco 21/26 - Page 22

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7.5.2 Pump Control Panel
Wilo Yonos PARA RKC circulating
pumps have two possible setting
modes:
• Constant speed with three pump
speed settings (I, II and III)
• Variable pressure (∆p-v) with pump
head adjustable between 1 and 7m
head
Figure 7-3 shows the pump control
panel with the red selector knob.
Constant Speed Mode (I, II, III)
This is the default setting of the pump
and as such is recommended by Grant
for heating systems. In this mode
the pump speed is not automatically
regulated (as with the Variable Pressure
Mode), but operates at constantly at
one of the three possible speeds (set
using the red selector knob on the pump
control panel).
Variable Pressure Mode (
∆p-v)
In this mode the electronic control
changes the differential pressure
setpoint to be maintained by the pump
in a linear fashion between Hs (the value
set using the red selector knob on the
pump control panel) and ½ Hs. The
differential setpoint varies linearly with
the volume flow Q.
7.5.3 Indicator LED
The pump is fitted with an indicator
LED. This is located around the
circumference of the red selector knob.
See Figure 7-3 below. This indicates the
operating status of the pump and will
be illuminated green when the pump is
operating normally. This indicator LED
can assist in diagnosing and rectifying
faults. Refer to Section 12.3.
7.5.3 Setting the Pump Control Mode
Set the pump to one of the two
operating modes as follows:
Constant Speed Mode (I, II, III)
Grant recommends this operating mode
for the pump.
To set the pump to the ‘Constant
Speed’ mode, the pointer on the red
selector knob must be set to the RIGHT
of the mid position. Refer to Figure 7-3.
Set it to point at the required speed
setting, I, II or III as required, ensuring
that there is adequate flow to distribute
the heat from the boiler whilst avoiding
high water velocities causing noise in
the pipework.
Variable Pressure Mode (
∆p-v)
To set the pump to the ‘Variable
Pressure’ mode the pointer on the red
selector knob must be set to the LEFT of
the mid position. Refer to Figure 7-3.
The further anticlockwise it is set the
greater the pressure head setting of the
pump – from 1m to 7m head.
If this mode is to be used, set the
selector knob at a pressure that
represents the maximum pressure
(head) loss for the heating system in
question.
Variable Pressure Mode
settings: 1 to 7m head
Indicator LED
Constant Speed Mode
settings: I, II, III
Red selector knob
Figure 7-3: Control panel with red selector knob and LED indicator