Johnson Controls SAB 355 - External Oil Filter; Unit with Double Oil Filter

Engineering manual - SAB 355 Screw compressor unit (including ATEX)
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004100 en 2020.10
Technical description
Fig. 24
Note: The sectional view shows the valve structure. Some of the internal oil channels are not
visible.
4.1.13 External oil filter
The compressor unit is equipped with an external oil filter, pos. 195/196, which is mounted in the
oil pipe between the oil separator or oil cooler (if present) and the compressor.
The external oil filter may be constructed with either one or two parallel filters.
Fig. 25: External oil filter
The filter is a horizontal filter through which the oil must pass the filter cartridge from the inside
out. This way dirt will accumulate inside the filter cartridge and thus not fall into the filter housing
when replacing the filter cartridge. The filter is protected against bursting because Unisab III will
stop the compressor if the pressure drop across the filter exceeds 1 bar.
Stopping the compressor at a too high differential pressure will happen with a 600 second delay
as the pressure difference may momentarily exceed 1.7 bar if the compressor is started up with
cold oil.
4.1.14 Unit with double oil filter
If the unit is equipped with two parallel oil filters, only one filter at a time must be in operation.
The filter not in use can be cleaned when the compressor is in operation.
6
8
10
2
7
9
1
5
In
Out
3
4
D
Oil draining/purging Filter cartridge