MEDC DB3B Manuel Technique page 5

AC version Ex de wiring details (Types 3 & 4)
Type 3: Connect the live and neutral
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supply wires to the terminals as detailed in
the wiring diagram. When power is
applied to the unit, the stage 1 tone will
be produced as selected on the 5- way
DIP switch inside the Ex d chamber.
Type 4: Connect the live and Neutral
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supply wires to the terminals as detailed in
the wiring diagram. When power is
initially applied to the unit, no tone will be
produced. Connect wires and remote
switches to terminals R0, R1 and R2 as
shown. When the switch connected to R1
is closed, the stage 1 tone will be
produced as selected by the 5-way DIP
switch on the electronics assembly. When
the switch connected to R2 is closed, the
pre-selected tone for stage 2 is produced.
See tone table 2 for details of pre-selected
tones.
Note: Closing both switches will produce
no tone.
DC version Ex d & Ex de wiring details (Types 5 & 6)
These types can be configured in a number of different ways depending on requirements. See following sheet for
details of terminal layouts. Independent tone selection for all three stages is via the 3 off 5-way DIP switches fitted
to the electronics assembly:
2-wire system (Single/dual stage): Connect the positive and negative supply wires to the terminals as
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detailed in the wiring diagram. The second stage is produced by reversing the polarity of the supply to the
unit.
3-wire system (Single/dual stage, common +ve): Connect three supply wires to the terminals as detailed
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in the wiring diagram (One common +ve wire and two -ve wires). Stage 1 is produced when power is
applied across the common +ve and stage 1 -ve terminals. Stage 2 is produced when power is applied
across the common +ve and stage 2 -ve terminals.
3-wire system (Single/dual stage, common -ve): Connect three supply wires to the terminals as detailed
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in the wiring diagram (two +ve wires and one common -ve wire). Stage 1 is produced when power is
applied across the stage 1 +ve and common -ve terminals. Stage 2 is produced when power is applied
across the stage 2 +ve and stage common -ve terminals.
4-wire system (Triple stage, Common +ve): Connect four supply wires to the terminals as detailed in the
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wiring diagram (One common +ve wire and three -ve wires). Stage 1 is produced when power is applied
across the common +ve and stage 1 -ve terminals. Stage 2 is produced when power is applied across the
common +ve and stage 2 -ve terminals. Stage 3 is produced when power is applied across the common
+ve and stage 3 -ve terminals.
4-wire system (Triple stage, Common -ve): Connect four supply wires to the terminals as detailed in the
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wiring diagram (Three +ve wires and one common -ve wire). Stage 1 is produced when power is applied
across the stage 1 +ve and common -ve terminals. Stage 2 is produced when power is applied across the
stage 2 +ve and common -ve terminals. Stage 3 is produced when power is applied across the stage 3
+ve and common -ve terminals.
All versions are supplied with terminals to allow loop-in loop-out connection of the supply wires.
If an EOL resistor is specified when ordering, it will be connected across teminals 5 & 6 as shown. If the unit is to
be used in a 4-wire, triple stage, common negative configuration, the EOL in the Ex d chamber must be moved to
terminals 7 & 8.
When positioning the EOL, ensure there is a minimum of 14mm free space between the resistor body and terminal
block and ensure the resistor is not in contact with the pcb or housing.
© MEDC 2014
05/14