Wiring - Deckma Hamburg OMD-2005 Instruction Manual

8.0

WIRING

(Refer to Fig. 4 + 5)
See Section 2 for important notes concerning wiring.
This unit must be connected to the mains supply via a suitable rated and
approved fused isolator unless such fusing / isolation is provided by associated
equipment. When fitted, the isolator should be close, readily accessible and
marked as to function.
Electrical connections are made through the metric cable gland openings
prepared underneath the instrument.
Fig. 4
Precise wiring details will vary dependent upon the control system to be
employed but the most frequently used systems employ alarm relay 1 for alarm
only and alarm relay 2 for control purposes.
Electrical connections are made to the terminal blocks inside the computer
housing. Wires are connected to the terminals by pushing a suitable screwdriver
into the clamp holes to release the internal spring loaded clamps. After the wire is
inserted to the terminal and the screwdriver is removed, the wire is fixed.
If the instrument is operated at high voltages, additional care has to be taken to
provide reliable ground connections. Ground (PE) can be connected direct to the
terminal or, if this is not sufficient according local rules, to the computer housing
left side. In this case the plug needs to be replaced by a M6 screw with nut and
related washers.
The instrument provides a pilot voltage output at terminals 4&5. This is internally
connected to the power supply input (Terminals 1&2), but is fused by Fuse F1 (2
A). The pilot voltage can be used to supply additional external circuitry, e.g. alarm
lamps or electrical valves.
Please note: any device connected to the pilot voltage output must be rated for
the voltage the instrument is supplied with. Do not use the pilot voltage for driving
motors, heaters or other high load devices. The pilot voltage is intended for alarm
purposes only.
Issue: 27.05.08
DECKMA HAMBURG GmbH
Instruction Manual OMD-2005 Page 11 of 25