8
- The clock controlled installations allowing for 2
ambient room temperatures (daytime temperature
and reduced temperature) acts on the boiler or a
regulated three-way control valve.
- Installations equipped with a three-way valve.
Remarks :
The NXT circulator starts progressively and
automatically positions itself on the setting point.
The automatic adjustment of differential pressure by
the NXT monitoring system follows the load loss
variations of the thermostat controlled valves.
the NXT monitoring system automatically detects
potential sticking phenomena. It then initiates
unsticking cycles that are automatically programmed
until the circulator returns to normal operation.
4.3 Accessories
Supplied :
• coupling gaskets •
Recommended :
• Unions, 1" (DN25) for NXT 33-25,
Unions, 1"
1/4
(DN32) for NXT 53-32 • Unsticking device to
make freeing the motor shaft easier • Isolating valves •
5. INSTALLATION
5.1 Assembly (see Figs. 6 and 7)
- Make sure that the circulator is accessible.
- Direct mounting on pipe, preferably vertical, if
possible on the boiler return circuit; never at the low
point (to avoid the formation of deposits).
-
The motor shaft must be horizontal (see Fig. 7).
- The arrow on the pump casing indicates the direction
of water flow (
see Fig. 6
).
- Provide a discharge check valve and isolating valves
to facilitate removal and servicing.
If the circulator is insulated, it is best not
to block the notches on the motor
flange (see Fig. 6).
5.2 Orientation of terminal box
If necessary, the orientation of the motor, and thus of
the terminal box, can be changed.
- Remove the motor attachment screws and turn the
motor to the desired position.
Possible terminal box positions are at 3, 9, and 12
o'clock.
Take care not to damage the casing
gasket, and to refit it correctly.
5.3 Electrical connection
The electrical connection must be made by a
qualified electrician and comply with applicable
local standards.
Complete electrical information about the circulator is
given on the data plate.
Power supply network
Use a three-conductor cable (3 x 1,5 mm
2
H05 VVF) to
connect mains power to the corresponding terminals
of the circulator: phase (L), neutral (N), and earth ( )
(
see Fig. 10
).
The power cable must not touch the pipe or the
pump; make sure that it is away from any
moisture.
Check line protection and the mains voltage and
frequency.
The circulator must be connected to the mains via a
switch with an opening distance, on each pole, of at
least 3 mm. The power outlet must have an earthing
contact.
After making the electrical connections, put the cover
back on the terminal box.
6. STARTING UP
6.1 Filling, degassing
Never operate the circulator WITHOUT
WATER.
- Open the valves on both sides of the circulator and
fill the installation completely.
- Bleed the circuit at the high point.
- Bleed air from the circulator manually by unscrewing
the plug a few turns, without removing it completely
(
see Fig. 8
).
Risks of scald, pressure be high.
- When water flows out and there are no more air
bubbles, screw the plug back in.
6.2 Adjustments
- The differential pressure is adjusted to the type of
installation on the potentiometer of the terminal box
(
see Fig. 2-3
).
- Power up the motor to start the circulator.
Touching the motor may result in burns; its
temperature may be above 100 °C in operation.
7. SERVICING
The circulator needs no special servicing in operation.
After a prolonged shutdown, make sure that the
circulator turns freely.
ATTENTION !
ATTENTION !
ATTENTION !
ENGLISH