20-02245 REV E
9
MAINTENANCE
The RS-485 Controlled positioners were designed to provide a long lifetime of service
with minimal maintenance.
If the positioner is oil-filled, the recommended routine maintenance is limited to checking
the compensating fluid volume. For other maintenance, we recommend the positioner
be returned to the factory. If this is not possible, field maintenance and repair should be
limited to the procedures described in this manual. For unusual situations or if
additional field maintenance is required, please contact the factory for assistance. The
maintenance procedures covered in this manual are End Cap Removal and
Replacement, Seal Replacement, and Motor Removal and Replacement and, if
equipped with oil, Fluid Volume Checking.
FLUID VOLUME CHECK
(If equipped with oil)
The unit is shipped from the factory containing approximately 45.3 fl oz of SAE 10
spindle oil. The compensator fluid volume should be checked periodically to assure that
no fluid is leaking out of the unit due to worn seals, etc. This is done by a simple visual
inspection of the Bellofram end of the housing. A protective cover with holes for water
flow covers the Bellofram. When the fluid volume is normal, the Bellofram will expand
outward. Its position can be checked by visual observation through the holes or by
using a blunt probe (Q-Tip) inserted through the compensator cover. If fluid has leaked
out, the Bellofram will become flat or recessed into the housing, and the unit should be
recharged with fluid.
WORK AREA PREPARATION
Any work done on the internal parts of the positioner requires the unit to be opened. A
clean work area should be prepared to avoid getting dirt or other debris on the seals or
sealing surfaces, or inside the motor or precision harmonic gearing.
If the positioner is oil-filled, there is a high probability of spillage when the unit is
opened. Additional fluid, Spindle Oil 10, should be available for refilling and towels
should be available for cleaning.
END CAP REMOVAL
The end cap must be removed for any internal maintenance procedures.
CAUTION:
If the unit is oil-filled, it is internally pressurized by the compensator
Bellofram.
1.
Oil Filled - Using a ¼-20 x 2 bolt with a nut and washer, withdraw the
plunger to relieve the pressure on the Bellofram. Secure in withdrawn
position. If not oil filled, skip this step and begin at step 2.
