Operation - MEDC DB3 Technical Manual

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external terminal is for a supplementary bonding connection where local codes or authorities permit or require
such a connection.
Once termination is complete, carefully replace the cover assembly back onto the body, avoiding damage to
the mating surfaces. Replace the cover screws into the holes in the cover assembly and tighten evenly.
Ensure the O-ring is seated correctly on the cover during re-assembly. On Exd certified versions, ensure the
required maximum gap of 0.15mm is maintained between the cover and the base once assembled.
Wiring options
The unit is available in six basic configurations:
1. Exd - DC Input, single tone
2. Exde - DC input, single tone
3. Exd - DC input, dual tone
4. Exde - DC input, dual tone
5. Exd - AC input, single tone
6. Exde - AC input, single tone
Types 1 & 2 have 6 terminals labelled as T1 to T6. The supply should be connected to T1 (+ve), T3 (-ve),
loop out on T4 & T6 respectively
Types 3 & 4 have 6 terminals labelled as T1 to T6:
For a 2 wire system, the supply should be connected to T1 (+ve), T2 (-ve), loop out on T4 & T5 respectively
to produce tone 1. Tone2 is produced when the polarity of the supply is reversed T1 (-ve), T2 (+ve), loop out
on T4 & T5 respectively. Optionally an EOL resistor may be connected to T4, T5.
For a 3 wire system, the supply should be connected to T1 (common +ve), T2 (-ve 1) & T3 (-ve 2), loop out
on T4, T5 & T6 respectively. Tone 1 is produced when the supply is connected to T1 (Common +ve) & T2 (-
ve 1). Tone 2 us produced when the supply is connected to T1 (common +ve) & T3 (-ve 2). Optionally an EOL
resistor can be connected to T4, T5 or T4, T6.
Type 5 has 4 terminals labelled as L, L, N, N. The supply should be connected to one L,N pair of terminals,
loop out on the second L,N pair of terminals
Type 6 has 6 terminals labelled as T1 to T6. The supply should be connected to T1 (L), T2 (N), loop out on
T4 & T5 respectively.

3.0 OPERATION

The sounder is available in various AC input voltage versions and a single DC voltage input version.
For AC versions, the nominal operating voltage is stated on the unit label and the supply voltage tolerance is
±10%
For DC versions, the absolute input voltage range is 11.0Vdc to 58.0Vdc
The DC version can be operated as a dual-tone unit (if specified when ordering). The unit can be switched
between the two tones by either:-
a. Reversing the polarity of the supply (2 wire versions)
b. Connecting as a 3 wire common +ve system and switching between the two -ve lines.
Note: - with T1 (+ve), T2 (-ve) tone 1 is produced (as set by DIL switch 'TONE 1')
- with T1 (+ve) T3 (-ve) or T1 (-ve), T2 (+ve) tone 2 is produced (as set by DIL switch 'TONE 2')
The unit is fitted with a volume control which is positioned adjacent to the DIL switches on dc units and is
mounted on the transformer on ac units. Maximum volume is obtained when this control is turned fully
clockwise.Minimum volume is obtained when this control is turned fully anticlockwise. Please note that on
the EN54-3 compliant version the minimum sound output is 65dB
WARNING: Do not attempt to turn the volume control past its limits of movement as this may cause damage
to the unit.
© Cooper MEDC 2013
Title:
DB3 TECHNICAL MANUAL
PROCEDURE/
DOCUMENT NO.
3
DD036-0 -03