Assortment / System Description

45
Relay outputs with… Number of
modules
Extension module
Universal
inputs
Analog
outputs
Ch’over contact NO contact
3 Universal module RMZ785 8 -- -- --
3 Universal module RMZ787 4 -- 1 3
3 Universal module RMZ788 4 2 1 1
3 Universal module RMZ789 6 2 2 2
Maximum number of modules: 3 per RMK770 (for extension modules, see page 57)
• Heat generation with a maximum of 6 boilers
• Heating sections of ventilation or air conditioning plants
• Heating systems with own heat generation
• Basic load heating systems
• Up to 7 control systems with modulating output (3-position or DC 0…10 V)
acting on …
– modulating burner,
– heating circuit with mixing valve,
– precontrol with mixing valve,
– maintained return temperature with mixing valve.
• Control of a maximum of 7 pumps (single or twin pumps or combinations of
them, e.g. 4 single pumps and 3 twin pumps)
• Monitoring pump overloads and pump flow
• Fault indication with red LED, acknowledgement with button
• 2 fault relays and 4 fault status inputs can be configured
• Acquisition and evaluation of main flow and main return temperature
• Sequence control of a maximum of 6 boilers
• Definition of boiler sequence (lead boiler):
– Automatically: Lead boiler changes based on parameter settings (boiler
sequence mode: Auto)
– Manually (selection of boiler via operator unit)
– With signal via digital input
• 3 fault signal inputs, preconfigured for over-/underpressure and water shortage
• Acquisition and evaluation of heat requests (external setpoint, external DHW
request and frost protection via the KNX bus)
• Control outputs for up to 7 single or twin pumps
• Mixing valve and pump overrun, mixing valve and pump kick, frost protection
• Control of boiler temperature (max. 6 boilers) with 1-stage, 2-stage or
modulating burner (individual boiler settings)
• P- or PI control action (PID for the control of modulating burners)
• Island mode for boiler 1, which means autonomous operation of boilers 2…6
• Control of boiler temperature with 1-stage, 2-stage or modulating burner
(3-position or DC 0…10 V with feedback signal)
• Acquisition of flue gas temperature, alarm when limit value is reached
• Maximum and minimum limitation of boiler temperature
• Maintained return temperature controlled via mixing valve (3-position or
DC 0…10 V), or with bypass pump
• Control of a shutoff valve, with feedback signal
• Selection of boiler operating mode
Extension modules
Types of plant
General functions
Boiler sequence
control
Control functions
Control of boiler
temperature – in general
Control of boiler
temperature – per boiler