Terminal strips X2 and X3

Power supply

AC voltage connection

The BC9191 Bus Terminal Controller uses an integrated power supply to generate the supply voltage (Us) of 24 V_DC required for operation.

The connection for the integrated wide-range power supply unit is made via connections 41 (L), 42 (N) and 43 (PE) of terminal strip X3.
This supply voltage supplies the electronics of the BC9191 as well as the electronics of the connected Bus Terminals via the K-bus.
It is electrically isolated from the field level voltage.

Power contacts supply (Up)

If the BC9191 is expanded with Bus Terminals, these must be supplied with Up via a power supply terminal.

Terminal strip X2

Terminal point	Designation	Connection	Comment
20	AO 1	Analog output 1	Analog output 0...10 V, e.g. air volume control
21	GND	GND	GND for analog outputs
22	AO 2	Analog output 2	Analog output 0...10 V, e.g. air volume control

Both analog outputs can be loaded with max. 10 mA. A connected actuator should have an internal resistance greater than 1 kOhm.

Terminal strip X3

Terminal point	Designation	Connection	Comment
30	2 kW	K1	Potential-free relay, 230 V~, 10 A, e.g. for electrical auxiliary heating
31	2 kW	K2	Potential-free relay, 230 V~, 10 A, e.g. for electrical auxiliary heating
32	FAN 1	Fan Speed 1	Relay output, 230 V~, e.g. low fan speed
33	FAN 2	Fan Speed 2	Relay output, 230 V~, e.g. medium fan speed
34	FAN 3	Fan Speed 3	Relay output, 230 V~, e.g. high fan speed
35	L	Phase	Supply for relay, fan speeds 1 to 3
36	N	Neutral conductor	Neutral conductor, e.g. for fan
37	Y1	Triac output 1	Triac output 1, 230 V~, max 1 A, switches at zero crossing, e.g. "heating" valve
38	N	N	Neutral conductor for triac output 1
39	Y2	Triac output 2	Triac output 2, 230 V~, max 1 A, switches at zero crossing, e.g. "cooling" valve
40	N	N	Neutral conductor for triac output 2
41	L1	L1	Power supply connection 230 V~
42	N	Neutral conductor	Power supply connection N
43	FE	Functional earth	Ground connection, capacitively connected to GND