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Expo Technologies UK
T: +44 (0) 20 8398 8011
E: [email protected]
Expo Technologies US
T: +1 (440) 247 5314
E:[email protected]
Expo Technologies China
T: +86 532 8906 9858
E: [email protected]
b) IS - Intrinsically Safe Output
The power control and alarm outputs are volt free contacts which form part of an Intrinsically
Safe (IS) circuit which then provides power control or alarm outputs in a safe (unclassified)
area. These contacts must only be connected to IS circuits as the switch contacts are in the
hazardous area. In many instances these outputs may be connected to the Expo range of
MiniPurge
Interface Units (MIU).
Figure 7. Intrinsically Safe (IS) Option
c) PA - Power and Alarm
Figure 8. Ex de Power and Alarm (PA) Option
The terminal box is Increased Safety (Ex e) certified and incorporates the terminal connection
points for the alarm and interlock circuits. All contacts provided are volt free (dry).
Cable entry methods (for example conduit or cable glands) must be certified to IECEx, ATEX or
INMETRO standards. The main requirement is that IP66 (or better) ingress protection must be
provided by use of seals or washers.
