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bushing since it is adjusted at the factory to
c
provide proper clearance of the meter disk in
the magnet GAP when the jewel screw is
screwed completely into it.
c. Insert the pivot-wrench end of a combination
jewel-and-pivot wrench through the jewel
screw hole.
d. Replace with a new pivot.
e. Disassemble
jewel-setting plug with a new one, reassemble
and re-oil according to instructions given pre
viously.
f.
Assemble the repaired jewel screw, or a new
ope, screwing it into the adjustable bushing as
far as it will go.
g. Should the disk need adjusting for proper
clearance in the retarding magnet gap, this
may be accomplished by loosening the clamp
ing screw of the guide bushing and moving
the guide bushing and jewel-screw assembly
up or down as desired.
h. Reset the top bearing by pushing the disk of
the moving element up against the top of the
retarding magnet gap and the electrical stator
gap,
and
clamping screw.
for the top bearing, and it is recommended that
this be followed.
3. Lubrication of Open-type Ball Bearing
It is recommended that no lubrication be used with
this type of meter bearing.
4. Replacement of Open-type Ball Bearing
If the meter requires a new jewel, the following
procedure, with reference to Fig. 2, is recommended
for replacement of an open-type ball bearing.
a. Loosen the top bearing clamping screw so that
the bearing plug is free to move.
b. Remove the jewel screw from its adjustable
bushing.
bushing since it is adjusted at the factory to
c:
provide proper clearance of the meter disk in
the magnet
screwed completely into it.
c. Insert the special jewel-assembly wrench, Cat.
No. 4131823, through the jewel-screw hole.
Engage the upper jewel assembly and un
screw.
d.
Replace upper jewel assembly.
e.
Replace lower jewel assembly with a new as
\
sembly and ball.
(b) is tight on the jewel screw (d).
f.
Carefully screw the lower jewel screw into the
adjustable guide bushing (e) in the watthour
Engage the pivot and unscrew.
the
jewel
screw,
replace
then
tightening
the top bearing
This gives the proper setting
Do not disturb the setting of this
gap when the
jewel
Check to insure that sleeve
Polyphase Switchboard Watthour Meters
meter frame, as far as it will go.
g. Should the disk need adjusting for proper
clearance in the retarding magnet gap, this
may be accomplished by loosening the clamp
ing screw of the guide bushing and moving the
guide bushing and jewel-screw assembly up
or down as desired.
h. The top bearing should then be reset by push
ing the disk of the moving element up against
the
the top of the retarding magnet gap a�d the
electrical driving stator gap, and tightening
the top bearing clamping screw.
the proper setting for the top bearing, and it
is recommended that this be followed.
Register
The register dial face may be cleaned by the use of
a cloth moistened slightly in water.
When replacing a register, carefully inspect the
mesh of its wormwheel with the worm on the disk
shaft to see that it is approvimately 1/3 to 112 the
length of tooth of the register wormwheel.
means for its adjustment is provided in the eccentric
adjusting screw in the bracket on the back of the regis
ter.
Avoid meshing too deeply, which might cause
friction and effect the accuracy of the meter.
The use of oil on the bearings of watthour meter
registers is not recommended.
Refer to separate Instructions for proper care of
the demand registers used on Types DSM
-35, -38 to -41 incl., -43, and -44 meters.
Stators
In case a potential or current coil is damaged the
entire stator should be replaced.
The watthour constant, or the watthours per revo
lution of the meter disk, is marked on the nameplate or
In the case of transformer-rated meters, the Kh
disk.
is the over-all constant for the meter with its trans
The "Test K" on the nameplate, however,
formers.
is the watthour constant to be used when testing the
meter without its transformers.
All electric central station companies should be
screw
is
equipped for periodic meter calibration.
of making such tests is by the use of a reliable timing
device and indicating instruments.
is no question regarding the accuracy of this method,
the portable watthour-meter standards manufactured
by the General Electric Company provide a means
for testing more quickly, yet accurately and independ
ently of load variations.
hour meters accompany each portable standard.
ies may also be obtained on application to the General
Electric Company.
GEH764AB
19, -20, -34,
-
TEST CONSTANT
TESTING
One method
Although there
Instructions for testing watt
This gives
If not, a
Cop
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