Viessmann VITOCAL 300-G Technical Manual page 24

Design information
Power-OFF
It is possible for the power supply utility to shut down the compressor
and instantaneous heating water heater (if installed). The ability to
carry out such a shutdown may be a power supply utility requirement
for providing a lower tariff.
Single stage heat pump
D
E
F
3
K
C
A Heat pump type BW, WW
C DHW cylinder
D Outside temperature sensor, sensor lead (2 x 0.75 mm
E DHW circulation pump, power cable (3 x 1.5 mm
F Cylinder temperature sensor, sensor lead (2 x 0.75 mm
G Junction box
H Motorised two-way valve, normally closed
K Cylinder primary pump (DHW side), power cable (3 x 1.5 mm
L Circulation pump for cylinder heating (heating water side), power
cable (3 x 1.5 mm 2
or
Three-way diverter valve, power cable (5 x 1.5 mm
Recommendation: use the circulation pump for cylinder heating
as hydraulic balancing is better achieved than with the three-way
diverter valve.
M Circulation pump, primary circuit (brine), power cable (3 x
2
1.5 mm or
for circulation pump with thermal circuit breaker 5 x 1.5 mm
If a 400 V~ circulation pump is used, it should be connected via a
contactor relay.
Type WW: Note the following additional components:
■ Well pump (If a 400 V~ well pump is used, it should be connected
via a contactor relay.)
■ Flow limiter
■ Frost stat
■ Separating heat exchanger
Recommended power cables:
Type
BW 121, WW 121
BW 129, WW 129
BW 145, WW 145
Line lengths in the heat pump plus wall clearance:
Type
Heat pump control unit power supply (230 V~) 1.0 m
Compressor power supply (400 V~)
Additional power cables
VIESMANN
24
(cont.)
M
G
L
H
A
2 )
)
2
Heat pump control unit
(230 V~)
2
5 x 1.5 mm
5 x 1.5 mm 2
2
5 x 1.5 mm
BW, WW
1.0 m
1.5 m
This must not shut down the power supply to the heat pump control
unit.
O
U
P
R
S
O Secondary pump, power cable (3 x 1.5 mm
Further circulation pumps are required for heating water buffer
2 ) cylinders, heating circuits with mixers and external heat sources;
see system scheme, page 33.
P Instantaneous heating water heater (on site):
2
)
An instantaneous heating water heater (on site) can only be
installed outside the heat pump. The flow temperature sensor
system must be installed in the direction of flow downstream of
2
)
the instantaneous heating water heater.
■ Power cable: See details provided by manufacturer
■ Control via heat pump control unit
R Heat pump control unit power cable, 230 V~, 50 Hz (5 x
)
1.5 mm 2 ) with power-OFF contact
S Compressor power cable, 400 V~ (see table)
U Electricity meter/mains
2 )
Note
For heating water buffer cylinders, heating circuits with mixers, exter-
nal heat sources (gas/oil/wood) etc., additional supply and control
cables and sensor leads must be factored in.
Check the core cross-section of the power cables and enlarge if
required.
Compressor (400 V~)
2
4 x 2.5 mm
4 x 4.0 mm 2
2
4 x 6.0 mm
2 )
Max. cable length
50 m
50 m
40 m
BWS
A connecting cable is used for the power sup-
ply
1.0 m
Connecting cable
VITOCAL 300-G