Heating Circuit Control; Control Systems; Logamatic 4212 Control Unit; Logamatic 4311 Und 4312 Control Units - Buderus Logano GE315 Technical Manual

5

Heating circuit control

5.1

Control systems

A control unit is required to operate the boilers. Buderus
Logamatic control systems are designed as modules. This
enables the selection of well-matching and economical
units for all applications and stages of development in the
proposed heating system.
Depending on the requirements and structure of the
heating system, the following options are available to
control the boiler:
• Control units in the Logamatic 4212 series (ZM 427 for
required boiler operating conditions)
• Control units in the Logamatic 43xx series
A burner control panel may be required for the contactors
controlled by the control unit. Alternatively, the contactors
can be integrated into the Buderus control panel system.
For more details on the Logamatic 4212,
4311 and 4312 control units, see the
technical guide on the Logamatic 4000
modular control system.
5.1.1

Logamatic 4212 control unit

The Logamatic 4212 control unit is a constant control unit
for 2-stage or modulating operation of the burner. Its
equipment level includes a temperature controller
(adjustable to 90/105 °C), a high limit safety cut-out
(adjustable to 100/110/120 °C), a boiler water
thermometer, a burner fault display, a test key for the high
limit safety cut-out, an On/Off switch and two slots for
hours run meters. The ZM 427 auxiliary module available
as an accessory safeguards the required boiler operating
conditions. It is supplied together with an additional
temperature sensor.
6 720 646 864 (12/2010) – Technical guide Logano GE315, GE515 and GE615
5.1.2

Logamatic 4311 und 4312 control units

The Logamatic 4311 and 4312 control units have the
same standard safety equipment level as the
Logamatic 4212 control unit (
The Logamatic 4311 control unit is suitable for low
temperature or condensing operation in a single boiler
system with up to eight heating circuits with actuators.
For 2- or 3-boiler systems, a Logamatic 4311 control unit
is required as a master control unit for the first boiler. In
addition, a Logamatic 4312 control unit is required as a
lag control unit for each of the second and third boilers.
With the relevant function modules (additional
equipment), this appliance combination can control up to
22 heating circuits with actuators.
Furthermore, the combination of several control units
(e.g. Logamatic 4122 with Logamatic 4323) connected
by ECO-CAN BUS (up to 15 addresses) offers virtually
unlimited functionality (up to 120 heating circuits).
Fig. 22 Logamatic 4311 und 4312 control units
1 Logamatic 4311 (optional full equipment level)
blue additional equipment
2 Logamatic 4312 (standard equipment level)
blue slots for additional equip
Heating circuit control
chapter 5.1.1).
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