4
Structure and functions
NK8237 hardware
20
Building Technologies
A6V10854379_a_en
CPS Fire Safety
25.01.2019
X101 onboard relay output.
Pin
Signal
Circuit
1
Common
X101
1
2
3
NO
NC
2
NO
3
NC
The input signals can be used for acquiring external power supply supervision
lines, for example, to supervise the fire system power supply. Note that this is an
alternative to the DF8090 power supply supervision (see I2C interface: DF8090
X102 onboard inputs.
Pin
Signal
Circuit 1
(internal power supply)
Circuit 2
(external power supply)
1
Input 1 (Mains
failure)
X102
1, 2, 3
4
5
6
4K7
100R
X102
1, 2, 3
4
5
6
4K7
100R
2
Input 2 (Battery fault)
3
Input 3 (Power
supply fault)
4
Common
5
+ Val
6
- Val
6.1.6
I2C interface: DF8090 power supply supervision
The I
2
C interface (X11) allows for a direct support of:
⚫
Power supply supervision: one DF8090 power supply supervision module.
The module can be installed on the DIN-rail, next to NK8237 unit.
Note: Although it can be supported, the DF8090 is not frequently used in the
NK8237 installations, which typically rely on the fire system power supply and the
related supervision, whose signals are acquired on the X102 onboard inputs.
Note also that the DF8090 signals are not reported on the IEC interface.
DF8090 Power Supply Supervision
DF8090 is a module designed for monitoring a 12V DC power supply. It can detect
the conditions listed below, shown on the DF8090 local panel and report them to
NK8237, and in turn to the management station (see the following):
⚫
Mains failure (no 220VAC)
⚫
Battery low
⚫
Power supply failure (trouble with AC/DC converter)
⚫
Battery protection fuse blown (internal micro-fuse type MSF 3.15A/250V)