MERLIN NX ROOM CONTROLLER – INSTALLATION & COMMISSIONING INSTRUCTIONS
EN1Z-1035GE51 R0319
18
with a current of more than 300 mA (320 mA for max. 2
minutes).
Nevertheless, the ensemble of triacs can be loaded for very
short periods of time (on the order of milliseconds) with a
current on the order of 2500 mA typically encountered when
switching on multiple thermal actuators.
Universal Inputs
The terminal blocks containing the controller's universal
inputs are blue. Universal input types: See Table 4.
The universal inputs are protected against voltages of max.
29 VAC and 30 VDC (due to, e.g., miswiring).
Bias Resistors
Each universal input is equipped with one bias resistor. See
Fig. 25.
UI
GND
SENSOR
R
DOWN
R
BIAS
R
SER
S2
S1
ADC
V
UP
Fig. 25. Schematic of universal inputs and bias resistors
LEGEND:
V
UP
=
10 V (except for UI1-4 of RL8N, which have 24 V).
R
BIAS
=
Bias resistor (with a resistance of 24.9 k
Ω
in the
case of NTC10k
Ω
and
NTC20k
Ω
sensor inputs,
and 7.5 k
Ω
in the case of Pt1000 sensor inputs);
can be switched OFF via software by S1 to support
0…10 V inputs without bias current ("high
impedance") – except in the case of UI1-4 of
RL8N, which have a resistance of 11.8 k
Ω
and
cannot be switched OFF.
R
SER
=
Series resistor for voltage dividing and filtering
(with a resistance of 150 k
Ω
).
R
DOWN
= An internal load resistor (with a resistance of
49 k
Ω
); depending upon the given type of con-
nected sensor, the firmware may switch this
resistor OFF.
Analog Outputs
The terminal blocks containing the controller's analog outputs
are green. Analog output types: See Table 5.
The analog outputs of the RLxN controllers (large housing)
are protected against voltages of max. 29 VAC and 30 VDC
(due to, e.g., miswiring).
NOTE:
Connecting 24 VAC to any analog output of the
RSxN controller (small housing) will damage the
hardware.
Free I/O Option
The limitations – including model-dependent limitations – set
forth in Table 2, Table 3, Table 4, Table 5 apply. Further
limitations are explained below.
Free Universal Inputs
Max. 5 BACnet Analog Input Objects
Under the free I/O option, a maximum of five of the MERLIN
NX controller's unused UIs are available for use as analog
inputs by the plant controller. However, they cannot be used
for receiving input from NI1000TK5000 sensors.
Max. 5 BACnet Binary Input Objects
Under the free I/O option, a maximum of five of the MERLIN
NX Controller's unused UIs are available for use as binary
inputs by the plant controller.
Max. 2 BACnet Accumulator Objects
Under the free I/O option, a maximum of two of the MERLIN
NX Controller's unused UIs are available for use as
accumulators by the plant controller.
These accumulators can have up to 30 Hz (pulse ON ≥ 16
ms; pulse OFF ≥ 16 ms; closed: voltage < 1 V; open: voltage
> 5 V).
These accumulators can be used, e.g., for energy meters
which create pulses when energy is consumed.
Free Outputs
Max. 4 BACnet Analog Output Objects
Under the free I/O option, a maximum of four of the MERLIN
NX Controller's unused outputs (analog or binary outputs)
may be used with BACnet Analog Output objects by the plant
controller. Possible characteristics are as follows:
▪ analog output: 0(2)..10 V outputs;
▪ floating output: triac or relay outputs;
▪ PWM: triac outputs;
▪ 1-, 2-, 3-stage output: triac / relay outputs.
Max. 4 BACnet Binary Output Objects
Under the free I/O option, a maximum of four of the MERLIN
NX Controller's unused relays and triacs are available for use
as binary outputs by the plant controller. However, they can
be used only as ON / OFF binary outputs.
Example:
The customer wants the plant controller to use some of the
I/Os of the CLMERL2N not used by the application as free