Fluke Calibration 4184297, User Manual

Page: 37 / 48

Maintenance & Servicing
Top Plate Removal
5
5-9
3
1
2
4
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Figure 5-4. PCU Assembly - 22 mm
Table 5-4. PCU Assembly - 22 mm - Parts List
Item Description Part Item Description Part
1 Piston Spec 3 Bearing Cap 3918182
2 Cylinder Spec 4 O Ring 3867509
Top Plate Removal
Note
In order to perform maintenance procedures on the hydraulic system, the
Top Plate Assembly must first be removed from the instrument case.
1. Depressurize the system by slowly opening the Exhaust valve.
2. Disconnect any DUT from the test port.
3. Remove the 4 screws from the instrument top plate, (1 at the mid-point of each edge).
W
Caution
The top plate will be connected to the instrument case by the
tubing that runs to the external supply manifold, so care must
be taken when lifting the plate to avoid damage to these
connections.
4. In most cases, the top plate can be lifted out vertically, but the system selector valve
fitted to the dual PCU (pressure & vacuum) models extends through the front of the
instrument case. For these instruments: Hold the top plate assembly by the test port,
and tilt the plate so that the rear edge is lifted, but the front edge remains in contact
with the instrument case.
5. Slide the top plate towards the rear until the selector valve is clear of the front lip of
the instrument case.
6. Carefully lift the top plate to reveal the inlet connection(s) from the external supply
manifold (mounted on the rear panel of the case).
7. Disconnect the tubing, and lift the top plate clear of the case.