Grundfos 509921, Instructions Manual

Page: 16 / 26

English (GB)
16
7.1 Setting the PWM input signal
To enable the external control mode (PWM profile A), you need a
signal cable connected to an external system. The cable
connection has three conductors: the signal input, the signal
output and the signal reference.
The cable is not supplied with the pump but can be ordered as an
accessory. The cable length must not exceed 3 metres.
Fig. 20 Mini superseal plug
Set the signal connection
1. Make sure that the pump is turned off.
2. Locate the PWM signal connection on the pump.
The three pins inside the signal connection are not energised.
3. Connect the signal cable with the mini superseal plug.
4. Switch on the power supply.
5. The pump automatically detects if a valid PWM signal is
available after which it enables the control mode on the pump.
See fig.
21 . If the pump does not detect a PWM signal or if the
signal equals 0, the pump will switch to the control mode
selected before connecting to a PWM signal.
Fig. 21 Connecting the signal cable to ALPHA1 L
8. Servicing the product
8.1 Dismantling the product
1. Switch off the power supply.
2. Pull out the plug. For instructions on how to dismantle the
plug, see section 8.2 Dismantling the plug .
3. Close the two isolating valves on both sides of the pump.
4. Loosen the fittings.
5. Remove the pump from the system.
8.2 Dismantling the plug
1. Loosen the cable gland and unscrew the union nut in the
centre of the terminal cover.
2. Detach the terminal cover.
3. Loosen the screws on the power supply plug and disconnect
the cable conductors.
4. Pull the power cable back through the cable gland and
terminal cover.
Conductor Colour
Signal input Brown
Signal reference Blue
Signal output Black
The cable must be connected to the control box via a
mini superseal plug. See fig.
20 .
TM06
44
1
4
TM
0
6
7
633
0
918
1 x 230 V - 15 %/+ 10 %
∽ 50/60 Hz
DANGER
Electric shock
Death or serious personal injury
- All electrical connections must be carried out by a
qualified electrician in accordance with local
regulations.
DANGER
Electric shock
Death or serious personal injury
- Switch off the power supply before starting any
work on the product. Make sure that the power
supply cannot be accidentally switched on.
CAUTION
Hot surface
Minor or moderate personal injury
- The pump housing may be hot due to the pumped
liquid being scalding hot. Close the isolating valves
on both sides of the pump and wait for the pump
housing to cool down.
CAUTION
Pressurised system
Minor or moderate personal injury
- Before dismantling the pump, drain the system or
close the isolating valves on both sides of the
pump. The pumped liquid may be scalding hot
and under high pressure.
All service must be carried out by an instructed
service technician.