Viessmann VITOCAL 300-G Installation And Service Instructions For Contractors page 38

Installation sequence
Electrical connection
4.
5.
BN BK
Fig. 24
Colour coding to IEC 60757:
BN Brown
BK Black
GNYE Green/yellow
System with heating water buffer cylinder
If the temperature limiter installed to restrict the maxi-
mum temperature of underfloor heating circuit
responds, the heating circuit pump of the relevant
heating circuit is switched off. The heat pump remains
on. The other heating circuits continue to be supplied.
Heating circuit
Without mixer A1/HC1
With mixer M2/HC2
With mixer M3/HC3
38
(cont.)
BN BK
BN
Connection
A
212.2 on main PCB
225.1 on expansion PCB
Plug at mixer extension kit
sÖ
BK
Assembling the temperature limiter: Steps 1 to 3 in
reverse order
!
Please note
If the temperature limiter installed to restrict the
maximum temperature of underfloor heating cir-
cuit is designed as an N/O contact, the heating
circuit pump will not start up.
Design the temperature limiter for restricting the
maximum temperature of underfloor heating cir-
cuit as N/C contact.
Circulation pump
Heating circuit pump
A1/HC1
Heating circuit pump
M2/HC2
Heating circuit pump
M3/HC3
See Fig.
C
25
26
27