MEDC DB20 User Manual

Page 4

3. OPERATION
The operating voltage of the unit is stated on the unit label.
Different sound levels can be obtained by selecting the transformer tappings in the unit (see table below):

Transformer

Power

Tappings

1:2

2:3

3:4

1:3

1.5W

0.75W

2:4

0.75W 0.375W

1:4

0.4W

0.2W

4. MAINTENANCE
During the working life of the unit, it should require little or no maintenance. However, if abnormal or unusual

environmental conditions occur due to plant damage or accident etc., then visual inspection is recommended.
If a unit fault should occur, then the unit can be replaced by MEDC.
If you acquired a significant quantity of units, then it is recommended that spares are also made available.

Please discuss your requirements with the Technical Sales Engineers at MEDC.

5. SPECIAL CONDITIONFOR SAFE USE:
For both IIB and IIC units:-
1. This apparatus is not suitable for use in atmospheres containing carbon disulphide.
2. Not more than one single or multiple strand lead shall be connected into either side of any terminal, unless

multiple conductors have been joined in a suitable manner, e.g. two conductors into a single insulated crimped

boot lace ferrule.
3. Leads connected to the terminals shall be insulated for at least 275V and this insulation shall extend to

within 1mm of the terminal throat.
4. All terminal screws, used and unused, shall be tightened down.
5. Minimum creepage and clearance distances between the terminals and adjacent conductive parts (including

cable entry devices) must be at least 5mm.
6. Painting and surface finishes, other than those applied by the manufacturer, are not permitted.

For IIC units only:-
7. When this unit is intended for use in dust atmospheres the cable entries shall be sealed, in accordance with the

applicable installation code of practice, to ensure that the IP66 to IP ingress protection rating is maintained.

6. CERTIFICATION/APPROVALS

UNITS CERTIFIED TO:
IIB VERSIONS:
EN 60079-0, EN 60079-1, EN 60079-7, prIEC 60079-0, IEC60079-1 & IEC 60079-7.
IIC VERSIONS:
EN 60079-0, EN 60079-1, EN 60079-7, IEC 60079-0, IEC 60079-1, IEC 60079-7, prIEC 61241-0 & IEC

61241-1

11/07