Switch Box; Establishing The Power Supply - Vaillant flexoTHERM exclusive VWF 57/4 Installation And Maintenance Instructions Manual

8 Electrical installation
8.3

Switch box

9
8
7
6
1 VR 32 modulating bus
coupler (optional)*
* If the system diagram
selected on the system
controller makes provi-
sion for this accessory,
it can be connected
here.
2 Controller PCB
3 VR 40 multi-functional
module (2 in 7) (op-
tional)**
** Relay 1 is used as
a fault contact connec-
tion/alarm output for the
heat pump. The func-
tion of relay 2 can be
set in the system con-
troller.
8.4

Establishing the power supply

1. Route the power supply line(s) through the holes in the
back wall of the product.
2. Guide the lines through the product, through the ap-
propriate strain reliefs and to the terminals of the mains
connection and controller PCB.
3. Wire the connections as illustrated in the connection
diagrams below.
Note
There is no provision for using a connec-
tion diagram on the controller or on the heat
pump operator control panel.
4. Tighten the strain reliefs.
22
1
2
3
5 4
4 Run capacitors
5 Start capacitor
6 In-rush current limiter
PCB
7 Line protection switch
8 Mains connection PCB
9 Mains connection ter-
minal for the auxiliary
electric heater
Installation and maintenance instructions flexoTHERM exclusive 0020213395_00
8.4.1 Connecting the continuous power supply
for the compressor and control system
▶
Connect the continuous power supply to the mains con-
nection (X101). (→ Page 36)
8.4.2 Connecting the blockable power supply for
the auxiliary heater
▶
Connect the power supply to the X102 mains connection.
(→ Page 36)
8.4.3 Connecting an external brine pressure
switch
In some cases (for example, in drinking water protection
areas), local authorities require the installation of an external
brine pressure switch that switches off the refrigerant circuit
if the pressure in the brine circuit falls below a certain level. If
the circuit is switched off by the brine pressure switch, a fault
message is shown on the display.
▶
Pull out the X131 plug for the bypass line (source monit-
oring) on the mains connection PCB.
▶
Connect an external brine pressure switch to the two
X131 terminals (Source Monitoring) on the mains con-
nection PCB.
–
Rated voltage of external brine pressure switch:
230 V 50 Hz
–
Power range for external brine pressure switch (rms):
1 ... 5 mA
8.4.4 Connecting a limit thermostat
In some cases where the underfloor heating has a direct
power supply, a limit thermostat (on-site) is essential.
▶
Pull out the S20 plug for the bypass line at terminal X100
on the controller PCB.
▶
Connect the limit thermostat at this terminal.
8.4.5 Connecting an external well pump
1
Lb La N
A changeover contact connection X143 (1) with the assign-
ment Lb, La, N, PE is provided for connecting an external
well pump.
Lb is the opening contact. If the cut-off relay contact to the
well pump is closed, there is no voltage at Lb.
2