Expo-Telektron Safety Systems MiniPurge Z & Y Purge Manual ...

Expo-Telektron MiniPurge Z purge Handbook ML 307 Issue A
6.6.2 Purge air from Control Unit to pressurized enclosure.
When the control unit is directly mounted onto the pressurized enclosure, no connection will
C:\Main System Files\Marketing\Memo\ML307 ISSUE A.doc
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normally be necessary, as the purge air will discharge into the pressurized enclosure directly.
When the control unit is not direct mounted, or where internal air distribution is necessary a
connection should be made from the purge air outlet on the control unit (normally ½” NPT
Female), via pipe pressure rated at least to the supply pressure, to the pressurized enclosure.
This should be kept as short as possible and should be adequately sized to ensure that the full
purge flow can be delivered.
6.6.3 Control Unit to enclosure pressure monitor.
When the control unit is directly mounted onto the pressurized enclosure, no connection will
normally be necessary, as the enclosure pressure monitor point will sense directly inside the
pressurized enclosure. Only if the control unit is not directly mounted or if there are fans, which
may create, localized low-pressure areas within the pressurized enclosure is it necessary to
pipe this connection. The connection is made to the enclosure pressure sensor fitting
(normally 1/8” NPT Female) on the control unit. There is virtually no flow in this circuit so small
bore tube may be used. Expo-Telektron recommends 6mm (¼”) bore tube. It is important that
all connections are free of leaks.
6.6.4 Control unit to flow sensor.
For Continuous Flow CF systems this function is performed by the enclosure pressure sensor
monitor connection. On Leakage Compensation LC systems this connection is made from the
enclosure flow sensor fitting (normally 1/8” NPT Female) on the control unit, to the fitting
(normally 1/8” NPT Female) on the Relief Valve (RLV). Tube and connections are all internal to
the pressurized enclosure. Again, Expo-Telektron recommends 6mm (¼”) bore tube.
6.6.5 Power supplies and their isolation
All power entering the pressurized enclosure must be controlled manually by the user.
Reference should be made to NFPA 496 or the relevant local codes.
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