Housing Purge - ABB EasyLine Series Instructions For Installation Start-Up And Operation

34 EasyLine EL3000 Series Commissioning Instructions

Housing Purge

Housing Design
When does a housing purge become necessary?
Purge Gas
Initial Purging for Start-up
Remark: Housing purge in the Fidas24 is described in a separate section,
see below.
Housing Purge is only possible with the wall-mount housing (EL3040
model). The purging gas connectors (1/8-NPT female thread) are factory-
installed based on orders.
Housing purge becomes necessary when the sample gas contains
flammable (see page 38), corrosive or toxic components.
The following is to be used as purge gas:

Nitrogen for measuring flammable gases and

nitrogen or instrument air for measuring corrosive or toxic gases
(Quality of instrument air in conformity with ISO 8573-1 Category 3,
i.e. particle size max. 40 µm, oil content max. 1 mg/m
max. +3 °C).
NOTE
For Uras26, the purging gas must not contain any constituents of the
sample components! Sample component constituents in the purging gas
can falsify the measurement result.
ATTENTION
Leaks may cause the purging gas to escape from the housing. When
applying nitrogen as purge gas, appropriate precautionary measures
must be taken against asphyxiation!
The purge gas flow must always be restricted upstream of the purge
gas inlet! If the purge gas flow is not restricted until after the purge gas
outlet, the full pressure of the purge gas is exerted on the seals. This
can destroy the operator panel keypad!
Purging of the gas feed path:
Purging of the wall-mount housing: Purge gas flow max. 200 l/h,
If the purge gas flow is lower than specified, the duration of the purging
must be extended accordingly.
3
, dew point
Purge gas flow max. 100 l/h,
duration approx. 20 s
duration approx. 1 h