Appendix A - 9438 080 24 V Dc Power Supply Unit (Optional); Description; Psu Dimensions; Accessing Psu Terminals - ABB 9438 User Manual

APPENDIX A – 9438 080 24 V DC POWER SUPPLY UNIT (OPTIONAL)
A.1 Description
The 24 V DC switch mode power supply unit is capable of
powering up to four separate 9438 dissolved oxygen system
solenoids. The 24 V is switched to the solenoid when required by
the operation of the calibration relay in the main 9438
transmitter.
Fig. A.3 shows the connection details in the PSU.
Fig. A.4 shows the interconnection between the PSU and a
single 9438 transmitter.
A.2 PSU Dimensions – Fig. A.1
Warning.
• Before making any connections, ensure that the power
supply, any high voltage-operated control circuits and
high common mode voltage are switched off.
• Although certain instruments are fitted with internal fuse
protection, a suitably rated external protection device,
e.g. fuse or miniature circuit breaker (m.c.b.), must also
be fitted by the installer.
Note. Make allowance for cable bends
160
23
M6 stud for
earth
145 CTRS
bonding
All dimensions in mm
Fig. A.1 Power Supply Unit Dimensions
34
A.3 Accessing PSU Terminals – Fig. A.2
62
136
98
Fixing screws M4
Slacken
captive
screws
Fig. A.2 Access to PSU Terminals