Safety Valve; Connecting The Equipotential Bonding - Viessmann Vitocell 100-W Installation And Service Instructions For Contractors

Connections on the DHW side
Equip the DHW circulation pipe with a DHW circula-
■
tion pump, check valve and time switch.
■ Connect the DHW circulation pump to the boiler con-
trol unit or via the time switch.
A
D
F
E
C
B
Fig. 7
Diaphragm 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 15), max. heat input 75 kW
½
If the heat input of the DHW cylinder exceeds 75 kW,
select an appropriately rated safety valve for the heat
input (see E-DIN 1988-200).
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.)
P
H
K M O
G
L N K
Permissible temperature
Permissible operating pressure
Test pressure
K R K P
O S T
Flow regulating valve
L
Pressure gauge connector
M
Non-return valve
N
Drain
O
Cold water
P
Drinking water filter
R
Pressure reducer
S
Non-return valve/pipe separator
T
!
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."
The safety valve must be installed above the top edge
of the DHW cylinder.
CH: Connect the equipotential bonding in accordance
with the requirements stipulated by your local power
supply utility and current SEV [or local] regulations.
Installation sequence
95 °C
10 bar
(1 MPa)
16 bar
(1.6 MPa)
11