Viessmann Vitoligno 300-H Installation And Service Instructions For Contractors page 36

Installation sequence
Electrical connections
Assignment of electrical connections on PCB (HKK) and extension kits (KM-BUS)
HKK PCB
1x HC at A1
2x HC at A1 and A2
3x HC at A1, A2 and A3
If 0x HC or 1x HC: TWE at A2
If 2x HC: TWE at A3
Note
Always connect TWE immediately downstream of HC
without a gap.
Exception: If only the TWE is connected to the HKK,
connect it at A2.
ZP, UP only at A2 or A3
ZP, UP possible in addition to TWE
SOL only at A3
Note
■ It is not possible to connect solar control module
type SM1.
■ Solar circuit at the boiler only possible if TWE or buf-
fer temperature sensors (3-5 sensors) are connected
to the Ecotronic.
36
(cont.)
Please note: Max. 4x HC can be connected in total.
Extension kits
1x HC at E1
2x HC at E1 and E2
3x HC at E1, E2 and E3
TWE at E1, E2 or E3
Note
Connect TWE downstream of HC without a gap.
VSB possible in addition to TWE