8
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6
8.5 Selection of control mode
8.5.1 Setpoint setting
The setpoint can be set by pressing
or
when
the pump is in control mode:
•
proportional pressure,
•
constant pressure or
•
constant-curve duty.
Set the setpoint so that it matches the system.
A too high setting may result in noise in the system
whereas a too low setting may result in insufficient
heating or cooling in the system.
If AUTO
ADAPT
is selected, the setpoint cannot be set.
8.6 Automatic nighttime duty
To be set on the control panel or with the R100, see
section 9. Pump setup.
Once automatic nighttime duty has been activated,
the pump automatically changes between normal
duty and night-time duty (duty at low performance).
Changeover between normal duty and nighttime duty
is dependent on the flow-pipe temperature.
The pump automatically changes over to
nighttime duty when the built-in sensor registers a
flow-pipe temperature drop of more than
18 °F - 27 °F (10 °C - 15 °C) within approx. 2 hours.
The temperature drop must be at least 0.18 °F/min
(0.1 °C/min).
Changeover to normal duty takes place without a
time lag when the temperature has increased by
approx. 18 °F (10 °C).
System type
Description
Select this
control mode
Typical heating
systems
Grundfos recommends to let the pump remain in AUTO
ADAPT
mode.
This ensures optimum performance at the lowest possible energy
consumption.
AUTO
ADAPT
Relatively great
head losses in
the distribution
pipes and
air-condition-
ing systems
1. Two-pipe
heating
systems with
thermostatic
valves and:
• with a pump head higher than
10 ft (3 m),
Proportional
pressure
• very long distribution pipes,
• strongly throttled pipe balancing valves,
• differential pressure regulators,
• great head losses in those parts of the system
through which the total quantity of water flows
(e.g. boiler, heat exchanger and distribution pipe
up to the first branching).
2. Primary circuit pumps in systems with great head losses in the pri-
mary circuit.
3. Air-condition-
ing systems
with
• heat exchangers (fan coils),
• cooling ceilings,
• cooling surfaces.
Relatively small
head losses in
the distribution
pipes
1. Two-pipe
heating sys-
tems with
thermostatic
valves and:
• with a pump head lower than
6.5 ft (2 m),
Constant
pressure
• with small head losses in those parts of the sys-
tem through which the total quantity of water flows
(e.g. boiler, heat exchanger and distribution pipe
up to the first branching) or
• modified to a high differential temperature
between flow pipe and return pipe (e.g. district
heating).
2. Underfloor heating systems with thermostatic valves.
3. One-pipe heating systems with thermostatic valves or pipe balanc-
ing valves.
4. Primary circuit pumps in systems with small head losses in the pri-
mary circuit.
1RWH
Automatic nighttime duty cannot be
used in air-conditioning systems.
