Assortment / System Description

54
Central control unit RMB795B
The RMB795B central control unit (see Data Sheet N3122) is used to control,
monitor and operate room groups with RXB/RXL room controllers or RDF/RDU/
RDG room thermostats.
• Management of 10 autonomous room groups with up to 63 room controllers or
room thermostats per room group and line in a KNX network
• Control unit for central use, with selectable time, calendar and special day
programs and predefined setpoints
• Yearly time switch with automatic summer-/wintertime changeover
• Time master for RX.. room controllers and RD.. room thermostats
• Monitoring of highest/lowest room temperature per room group
• Monitoring of RX.. room controllers and RD.. room thermostats
• Forwarding requests to the primary side
• Consumption data acquisition from pulse counters (gas, hot water, chilled water,
electricity; for display only, not for billing purposes)
• 10 freely configurable logic function blocks
• 4 autonomous trend channels to log measuring variables of local inputs and, via
KNX, room temperatures and the outside temperature
• Up to 32 universal transmit and reception zones per line for data exchange via
KNX in LTE and S-mode
• 1 freely configurable application based on basic type B
• Optimum start control: Before "Comfort" mode applies, rooms can be preheated
or precooled to the required temperature
• Priority of setpoints: It can be selected on the central control unit whether the
unit’s setpoints shall always
have priority in the room controllers (e.g. in
workshops) or not in
"Comfort" mode (in office spaces) or only when changed
(in hotel rooms), that is, whether they shall be overwritten
• Air flow balancing VAV: Settings "Simulation VAV supply air" and "Simulation
VAV extract air" activate the supply or extract air fan of the ventilation plant and
the respective VAV boxes open, enabling the volumetric air flow to be balanced
with the maximum air volume
• Fire alarm off: In an emergency, the devices assigned to a room group can be
switched off via input signal
• Smoke extraction: A room group can be switched to "Smoke extraction" mode
via 1 or 2 input signals
• 2-pipe system: The central control unit forwards changeover signal
"Heating/cooling" via the KNX bus to the room controllers
• KNX bus communication for operation and process information
• Menu-driven commissioning, operation and monitoring (cleartext)
• No commissioning tool required for basic plants (easy configuration)
• Complex plants are commissioned with the OCI700.1 service tool
Functions and characteristics
Relay outputs with… Product
no.
Universal
inputs
Analog outputs
DC 0...10 V
Ch’over contact NO contact
RMB795B 6 = N.X1…N.X6 2 = N.Y1, N.Y2 1 = N.Q1 3 = N.Q2, Q3, Q5
The universal inputs N.X_ can be configured for use with passive sensors, active
signal sources, and status and pulse signals (see page 28).
The analog outputs N.Y_ and relay outputs N.Q_ are ready configured.
Brief description
Inputs and outputs
Inputs
Outputs