2.4 Electrical installation
Figure 9 shows the electrical connection diagram of the NGC-20 controller. The limiter temperature sensor connection is only applicable
with the NGC-20-CL-E. The optional second Pt100 temperature sensor for the control unit is omitted for clarity.
W/B
W/B
R
R
R
R
PE
L1
N
PE
RS485 cable from
previous device
RS485 cable to
next device
To next NGC-20
Heating cable
PT100
temperature sensor
Only to be used for the LIMITER
PT100
temperature
sensor(s)
RTD 1
RTD 2
RS485
RS485 S
S
+
Li
Lo
Ni
No PE
PE
PE
Lo
No
Internal RS485
end of line
termination
resistor
When the device is the last on the communication
line install a wire bridge between the - and
T terminal as shown by the dotted line
Alarm
3A Max
Heater
+
–
– T
PE
RTD LIMITER
R
PE
R
PE
W/B
Figure 9: electrical connection diagram NGC-20
14 | nVent.com
