Viessmann VITOCAL 300-G Installation And Service Instructions For Contractors page 37

Electrical connection
Connecting a temperature limiter to restrict the maximum temperature of underfloor heating cir-
cuit
System without heating water buffer cylinder: Connection to X3.2/X3.14
If the temperature limiter installed to restrict the maxi-
mum temperature of the underfloor heating circuit
responds, the heat pump and the secondary pump are
switched off. The underfloor heating circuit is no longer
supplied.
X3.2
X1.
?
X3.14
A
Fig. 22
Temperature limiter to restrict the maximum tem-
A
perature of underfloor heating systems
!
Please note
If the temperature limiter installed to restrict the
maximum temperature of underfloor heating cir-
cuit is designed as an N/C contact, the heat
pump will not start up.
Design the temperature limiter to restrict the
maximum temperature of underfloor heating cir-
cuit as N/O contact.
!
Please note
Incorrect parameter setting may result in the
temperature limiter not immediately switching
off the secondary pump after being triggered,
but instead with a time delay.
Set "Effect of external blocking on pumps/
compressor 701A" to "16" (select "bit 5").
!
Please note
The function of the temperature limiter can be
disabled by other functions.
External hook-up, heating/cooling circuits:
■
External hook-up for heating/cooling circuits
(e.g. in conjunction with a Smart Home sys-
tem) must not be set: Do not set "Remote
control 2003, 3003, 4003" to "2".
■ Smart Grid:
For Smart Grid, use the EA1 extension
(accessories): Set "Enable Smart Grid 7E80"
to "1".
(cont.)
Converting temperature limiter part no. 7151728,
7151729 into a N/O contact
1.
2.
3.
Fig. 23
Installation sequence
37