Viessmann VITOCAL 242-S Installation And Service Instructions Manual page 44

Installation sequence
Electrical connection
Plug sYA
Terminals Function
211.2 Secondary pump
211.5 Cooling control
AC 3-way diverter valves for
heating water buffer cylin-
der bypass in cooling
mode
Plug sYS
Terminals Function
212.2 Heating circuit pump for
heating circuit without mixer
A1
(A1/HC1)
44
(cont.)
Explanation
■ In systems without a heating water buffer
cylinder, no other heating circuit pump is
required (see terminal 212.2).
■ Connect the temperature limiter to restrict
the maximum temperature for underfloor
heating systems (if installed) in series.
Connection values
■ Output: 130 W
■ Voltage: 230 V~
■ Max. switching current: 4(2) A
Secondary pump connected at the factory;
the temperature limiter must be connected
on site.
Connection values
■ Max. output: 10 W
■ Voltage: 230 V~
■ Max. switching current: 4(2) A
Connect the 3-way diverter valves for the
bypass circuit in parallel.
Explanation
■ This pump is connected in addition to
the secondary pump if a heating water
buffer cylinder is installed.
■ Connect the temperature limiter to re-
strict the maximum temperature for un-
derfloor heating systems (if installed) in
series (see the following chapter)
Connection values
■ Output: 100 W
■ Voltage: 230 V~
■ Max. switching current: 4(2) A