KROHNE BM 90 EN - Manual (Page 7)

7
Figure 2:
AC power supply - connected:
Earth to terminal 1
Neutral to terminal 2
Live to terminal 3
The instrument will automatically accept either 110V or
230V AC –10%, 50Hz or 60Hz, 12VA. A time lag fuse
T160mA is fitted.
DC power supply - connected :
Positive +ve to terminal 27
Negative -ve to terminal 28
The instrument will accept 24V DC + 25%, - 10%. 9W.
A time lag fuse T315mA is fitted.
5 SPDT Relays - rated 8A/250V AC/30V DC resistive,
with gold contacts for lower power switching, are connect-
ed to terminals 4 to 18, for activating external alarms,
contactors, pumps etc..
Transducer RZV15 - is connected:
Black to terminal 19
Blue to terminal 20
Screen to terminal 21
Temperature compensated transducer RZT15 -
is connected:
(Screen to terminal 19
Must enable Pr.37 (Blue to terminal 20
(Black to terminal 22
Isolated Analogue - is connected :
Screen to terminal 24
Positive +ve to terminal 25
Negative -ve to terminal 26.
Separate Temperature Compensation - when compen-
sation is provided by a separate temperature sensor, the
sensor should be connected with a shielded twisted pair
and connected:-
(Screen to terminal 21
Must enable Pr.37 (Core* to terminal 22
(Core* to terminal 23
* The polarity of the cores is unimportant, but it is impor-
tant that the screen is connected only at the instrument
end and not at the temperature sensor end.
1 2 3
E N L
L2 L1
AC POWER
110/230 VAC
+10%/-10%
50/60 HZ
12VA
19 20 21 22 23 24 25 26
27 28
+ -
DC Power
21.6-30VDC
9W
Isolated
Analog
Output
+ -
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
RELAY 1 RELAY
3
RELAY
4
RELAY 5 RELAY 2
2.1.2. Transducer Wiring for BM90 / L
The wall mount instrument has two-part screw terminals. It can be powered from either an AC or DC supply.
Simultaneous AC & DC powering can be done through an external relay which switch on the other power when the
main one is off. The relay contact will be released when main power is off. Ask for scheme if necessary.