Mounting notes
You must mount the central communication unit in a cabinet or control panel. Make
sure service can easily access the unit.
•
Standard mounting
On standard rail TH 35-7.5
•
Screwed-on mounting
Screwed to rear wall
•
Mounting position
Horizontal only
•
Mounting and dimensions See "Dimensions"
Installation notes
Important notes
Observe the following important notes for mounting and installation:
•
The central communication unit must be mounted in a cabinet or control panel,
as when mounted on a freely accessible wall, the relay output terminals
carrying mains voltage (bottom of the unit, terminals not covered) are not
protected against electric shock hazard.
•
Run fuses, switches, wiring and earthing as per local regulations for electrical
installations.
•
The relay contacts of the central communication unit can switch either mains
voltage or low-voltage. Applying both mains and low voltage is not permitted.
•
You must connect circuits with relay contacts Q11, Q12 through Q41, 42 to the
same mains phase.
•
You must connect circuits with relay contacts Q73, Q74 and Q83, Q84 to the
same mains phase.
•
Connect only potential-free contacts to digital inputs D1…D8 and universal
inputs X1…X8 (configured for digital inputs signals).
•
We do not recommend plant monitoring via PC interface in environments with
strong electromagnetic interference (e.g. in industrial environments with
electrical welding equipment).
Operating voltage
The central communication unit operates on AC 24 V and must meet requirements for
SELV/PELV (safety extra low-voltage / protective extra low-voltage).
Use only safety isolating transformers suited for 100 % duty (as per
EN 61558-2-6).
Wiring
Plan sufficient space around the unit for easy wiring. The unit’s terminals are arranged
to eliminate cross-wiring of input and output lines to prevent faulty wiring to the greatest
extent possible.
The terminals for digital inputs, universal inputs, and the KNX bus are located at the top
of the unit (low-voltage side). The terminals for AC 24 V operating voltage and relay
outputs carrying mains voltage are located at the bottom (mains voltage side).
The terminals are designed for wire diameters of min. 0.8 mm or cross-sections of
0.5...2.5 mm
2
. See "Technical data".
Connecting terminals
10/18
Building Technologies
Central communication unit OZW775 V2.0
CE1N5663en
HVAC Products
29.10.2008
