Control Unit - Honeywell NX series User Manual

6.2

Control unit

The control unit of the frequency converter consists roughly of the control board and additional boards (see
Figure 6-23 and Figure 6-24) connected to the five slot connectors (A to E) of the control board. The control
board is connected to the power unit through a D-connector (1) or fibre optic cables (FR9).
Figure 6-23. NX control board
Usually, when the frequency converter is delivered from the factory, the control unit includes at least the
standard compilation of two basic boards (I/O board and relay board) which are normally installed in slots A
and B. On the next pages you will find the arrangement of the
basic boards, the general wiring diagram
the factory are indicated in the type code. For more information on the option boards, see NX option board
manual (ud741).
The control board can be powered externally (+24V, ±10%) by connecting the external power source to
either of the bidirectional terminala #6 or #12, see page 68. This voltage is sufficient for parameter setting
and for keeping the fieldbus active. Note however that the analogue inputs and outputs as well as the
measurements of the main circuit (e.g. DC-link voltage, unit temperature) are not available when the mains
is not connected (with the exception of frame size FR9 and bigger).
Note! If the 24V inputs of several frequency converters are parallelly connected we recommend to use a
diode in terminal #6 (or #12) in order to avoid the current to flow in opposite direction. This might damage
the control board. See picture below.
CABLING AND CONNECTIONS
and the control signal
+ - + - +
#6 #7 #6 #7 #6
A
Figure 6-24. Basic and option board connections
on the control board
control I/O and the relay terminals
descriptions. The I/O boards mounted at
External
+24V
- + -
#7 #6 #7
nk6_17
65(110)
E
D
C
B
of the two
6