Plum ecoMAX920P1-S TOUCH, Installation And Operating Manual, Page: 39 / 48

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14.4 Buffer
Parameter Description
Buffer support
Parameter serves to activate buffer operating mode. It is available after connecting additional
module B and buffer temperature sensors.
Buffer loading start
temperature
Parameter Buffer loading start temperature defines the upper temperature of the buffer below which
the buffer loading process starts. Buffer loading process is ended when lower buffer temperature
reaches value defined by parameter
Buffer loading end temperature .
Buffer loading end
temperature
14.5 Mixer
Parameter Description
Thermostat selection
Parameter available only after connecting room panel. Option enables changing room thermostat for
mixer circuit.
Available options:

Off
– turns off the influence of room thermostat on mixer circuit operation,

Universal
– turns on standard room thermostat for mixer circuit,

ecoSTER T1..T3
, eSTER T1…T3 – option available after connecting room panel and makes
mixer circuit operation dependent on the thermostat in room panel. If room panel is
disconnected the controller operates only with standard room panel.
Mixer support

Off Mixer servomotor and mixer pump are not operating.

CH on
It applies when mixer circuit supplies CH heating installation. Maximum mixer circuit temperature is
not limited, mixer is fully open during alarms, e.g. boiler overheat. Attention: do not enable this
option when installation is made of pipes sensitive to high temperature. In such situations it is
recommended to set
Mixer support to Floor on.

Floor on
It applies when mixer circuit supplies floor installation. Maximum mixer circuit temperature is limited
to the value of
Max. preset mixer temp. parameter. Attention: after selecting option Floor on the
parameter Max. mixer temp. must be set to such value, so that the floor was not damaged and there
was no risk of scalding.

Pump only
When mixer circuit temperature exceeds temperature set in Mixer preset temperature the supply of
mixer pump will be off. After decreasing circuit temperature by
2ºC – pump is switched on again.
This option is usually used to control floor heating pump when it cooperates with thermostatic valve
without servomotor. However, such action is not recommended. It is recommended to use standard
heating circuit for floor heating, consisting in valve, servomotor and mixer pump.
Minimum mixer
temperature
It is a parameter with which user can be limited from setting too low preset mixer circuit temperature.
Automatic regulation (e.g. temporary temperature decrease) also will not cause decreasing of preset
temperature value below value set in this parameter.
Maximum mixer
temperature
The parameter has two functions:
- enables limiting setting too high preset mixer temperature by the user. Automatic regulation
(correction according to heating curve from outside temperature) also will not cause exceeding
preset temperature over the value set in this parameter.
- with parameter
Mixer support = Floor on is at the same time the limit temperature of mixer sensor
at which mixer pump will be off. For floor heating set the value not greater than 45-
50°C or other if
the manufacturer of materials used to construct the floor or CH installation designer specified
otherwise.
Valve opening time Enter Full valve opening time
value read from servomotor’s nameplate, e.g. 140 sec.
Pump off by
thermostat
Setting parameter to YES will close the mixer servomotor and switch off mixer pump after opening
room thermostat contacts (room heated). However this action is not recommended as the heated
room may be still cold.
Mixer dead zone
Parameter setting determining temperature dead zone value for the mixer control system. The
controller controls the mixer so that the temperature value measured by the mixer circuit sensor was
equal to the preset value. However to avoid too frequent servomotor movement, that can shorten its
lifetime, the control is initiated only when the measured mixer circuit temperature is higher or lower
from the preset by the value greater than
Mizer dead zone.