EXPO MiniPurge D825/ET, Руководство пользователя, Страница: 13 / 40

ML550 | v6
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Expo Technologies UK
T: +44 (0) 20 8398 8011
E: sales@expoworldwide.com
Expo Technologies US
T: +1 (440) 247 5314
E:sales.na@expoworldwide.com
Expo Technologies China
T: +86 532 8906 9858
E: qingdao@expoworldwide.com
Visual Indicators
Visual indicators are fitted to provide status information to the operator.
* The Green / Black combination indicates normal operation of the pressurized enclosure after the initial
purging cycle has been completed.
Relief Valve Unit
The Relief Valve Unit allows the purge air to exit the enclosure safely via a built-in spark arrestor. This spark
arrestor is designed to prevent the emission of arcs, sparks and incandescent particles produced within the
pressurized enclosure.
Purge air passes through the Relief Valve Unit; the preset pressure differential across the appropriate orifice
ensures that the purge flow sensor is activated once the selected purge flow has been attained.
During the purge cycle a pneumatic cylinder operates the Purge Outlet Valve that lets the air from inside the
enclosure exhaust through the Relief Valve Unit. When the system changes to leakage compensation mode, the
Purge Outlet Valve is closed and the enclosure sealed.
The Relief Valve Unit has an in-built relief valve.This is sized to ensure that, if the air supply pressure rises up
from the specified maximum, the internal enclosure pressure will not exceed the specified maximum working
pressure of the pressurized enclosure.
Explosionproof Terminal Box
The Terminal Box is flameproof Ex d Zone 1 Gas Group IIC, and explosionproof Class I and Class II Div 1 Grp
BCDEFG, and incorporates the terminal connection points for the alarm, power interlock and intermediate
outputs. All contacts provided are volt free (dry).
Cable entry methods (for example conduit or cable glands) must be suitable certified for the location of the
system and the type of cable being used. Cable entries are 1/2 in. NPT(F). Unused openings shall be blanked
with suitable certified flameproof/explosionproof plugs.
Alarm / Pressurized Indicator
Green*
Pressurized
Red
Pressure Alarm (enclosure pressure low)
System Purging Indicator
Black*
Purge flow too low (not in purge mode)
Yellow (flashing)
Purging (flow above minimum)
Alarm/Pressurized Switch
Intermediate Pressure Switch
Power interlock 125Vac 6A / 250Vac 3A
125 Vac 6A / 250 Vac 3 A
125Vac 1A