Safety Valve; Connecting The Equipotential Bonding - Viessmann VITOCELL 300-B Installation And Service Instructions Manual

Connections on the DHW side
F
H
G
K
A
D
A
B
C
B
Fig. 17 500 l capacity
Upper Internal indirect coil for connection to the
A
heat generator
Lower indirect coil for connecting to solar collec-
B
tors
Diaphragm expansion vessel
C
D DHW circulation pipe
Drain
E
DHW
F
Spring-loaded check valve
G
DHW circulation pump
H
Visible discharge pipe outlet point
K

Safety valve

The system must be equipped with a type-tested dia-
phragm safety valve as protection against overpres-
sure.
Permissible operating pressure: 10 bar (1 MPa).
The connection diameter of the safety valve must be
as follows:
Min. R (DN 20), max. heat input 150 kW
¾
Select a safety valve with a higher rating if the heat
input of the DHW cylinder is greater than the maximum
heat input assigned to the capacity. (See DIN 4753-1,
issue 3/88, section 6.3.1).
Install the safety valve in the cold water line. Ensure it
cannot be shut off from the DHW cylinder. There must
be no constrictions in the pipework between the safety
valve and the DHW cylinder.

Connecting the equipotential bonding

Connect the equipotential bonding in accordance with
the requirements stipulated by your local power supply
utility and VDE [or local] regulations.
(cont.)
S
L
M O
R
N P
M
E
M T M W
U V
R
Safety valve
L
Shut-off valve
M
Flow regulating valve
N
Pressure gauge connector
O
Non-return valve
P
Drain
R
Cold water
S
Drinking water filter
T
Pressure reducer
U
Non-return valve/pipe separator
V
Cold water
W
!
Please note
Never seal off the safety valve discharge pipe.
The overpressure can damage the system.
Ensure that any expelled water is safely and
visibly drained into a drainage system.
Position a sign close to the safety valve dis-
charge pipe, or ideally on the safety valve itself,
with the following inscription: "For safety rea-
sons, water may be discharged from the dis-
charge pipe during heating! Never seal."
Install the safety valve above the top edge of the DHW
cylinder.
CH: Connect the equipotential bonding in accordance
with the technical requirements stipulated by your local
power supply utility and SEV regulations.
Installation sequence
21