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

Connections on the DHW side
D
F
E
G
C
A
Fig. 15
Expansion vessel
A
Drain
B
DHW circulation pipe
C
DHW
D
Spring-loaded check valve
E
DHW circulation pump
F
Visible discharge pipe outlet point
G

Safety valve

H
Shut-off valve
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 safety valve must have the following connection
diameter:
R (DN 20), max. heat input 150 kW.
¾
If the heat input of the DHW cylinder exceeds 150 kW,
select a sufficiently large safety valve for the heat input
(see DIN 4753-1, issue 3/88, section 6.3.1).
Install the safety valve in the cold water pipe. It must
not be able to be isolated from the DHW cylinder. The
pipework between the safety valve and the DHW cylin-
der must not be restricted in any way.

Connecting the equipotential bonding

Connect the equipotential bonding in accordance with
the requirements stipulated by your local power supply
utility and VDE regulations.

Commissioning

Service instructions
(cont.)
P
H
K M O
L N K
B
K R K P
O S T
Flow regulating valve
L
Pressure gauge connection
M
Non-return valve
N
Drain
O
Cold water
P
Drinking water filter
R
Pressure reducer
S
Non-return valve/pipe separator
T
The safety valve discharge pipe must never be sealed
off. Discharge expelled water safely and visibly into the
drainage system. Position a sign close to the safety
valve discharge pipe or on the safety valve itself with
the following inscription: "For safety reasons, water
may be discharged from the discharge pipe during
heating. Never seal off."
Install the safety valve above the top edge of the DHW
cylinder.
: Connect the equipotential bonding in accordance
c
with the technical requirements stipulated by your local
power supply utility and SEV regulations.
17