Calling Up Heat Pumps - Viessmann VITOTRONIC 200 Service Instructions Manual

Heat pump cascade
Parameter
LON communication module installed
"Enable LON communication mod-
ule 7710"
"LON system number 7798"
"LON subscriber number 7777"
Each number may only be allocated
once.
"LON fault manager 7779"
Only one control unit per system
may be configured as the fault manag-
er.
"Source time 77FE"
"Send time 77FF"
"Source outside temperature 77FC"
"Send outside temperature 77FD"
"Interval for data transfer via LON
779C"
"Enable buffer cylinder/low loss
header 7200"
"Enable instantaneous heating wa-
ter heater 7900"
"Enable electric heaters for DHW
heating 6015"
"Enable electric heaters for DHW
heating 7901"
"Enable instant. heating water heat-
er for central heating 7902"
"Enable 3-way diverter valve heat-
ing/DHW 730D"

Calling up heat pumps

Only those heat pumps are called up that are enabled
for the required use, e.g. DHW heating with "Use of
heat pump in cascade 700C".
Without runtime balance ("Runtime balance cas-
cade 700D" set to "0")
If the return temperature in the secondary circuit is
undershot by the start hysteresis, the heat pump con-
trol unit first activates the lead heat pump. Lag heat
pumps are activated subject to output integral I
gral from duration and extent of deviation of set flow
temperature from actual temperature in the secondary
circuit).
Without runtime balance ("Runtime balance cas-
cade 700D" set to "1")
Runtime balancing in cascades takes place between
all lag heat pumps and the lead heat pump.
/
(cont.)
with output
A
control
"1"
"1" to "5"
"1" to "99"
"0" or "1"
"0"
"1"
"0"
"1"
"20"
"1"
"0" or "1"
"0" or "1"
—
"0" or "1"
"1"
(inte-
L
without out-
A B
put control
"1"
"1" to "5"
"1" to "99"
"0" or "1"
"0"
"1"
"0"
"1"
"20"
"1"
"0" or "1"
"0" or "1"
—
"0" or "1"
"0" or "1"
If the return temperature in the secondary circuit is
undershot by the start hysteresis, the heat pump con-
trol unit activates the heat pump with the shortest run-
time. This is not necessarily the lead heat pump. If fur-
ther stages of the output integral are exceeded (n-
times "Start threshold 730E"), one after the other the
remaining heat pumps are called up, from the shortest
runtime upwards.
Note on cascades with a 2-stage refrigerant circuit
The key factor for runtime balance in the cascade is
the runtime of compressor 1. In every heat pump, the
compressor that is started first is always the one that
was not running most recently.
Function description
C
"1"
"1" to "5"
"1" to "99" 1 to 99
"0" or "1" Device is al-
ways the fault
manager.
"1"
"0" Device receives
the time.
"1"
"0"
"20"
—
"0" or "1"
—
"0" or "1"
"0" or "1"
"0" or "1"
—
—
—
—
—
—
—
—
—
—
—
—
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