Specifications

18
4. Remove the spinner. Check the torque on the
blade nuts; the recommended value is 54 N.m
(40 ft-lbs). Check the front bearing cover for
seal integrity and grease loss. Check the al-
ternator bearings for lack of play, a tiny
amount of play is acceptable and normal, if it
appears excessive, pop the front bearing cov-
er off. This will expose the bearing adjust-
ment nut. Remove the cotter pin and tighten
the nut to just snug. DO NOT USE A
WRENCH, if the cotter pin will go through one
of the two holes in the alternator shaft then
push it through, if not BACK THE NUT OFF
(CCW) until a cotter pin will go through. Re-
place the front bearing cover. Reattach the
spinner and check that it is secure.
5. Check the screws holding the nacelle rubber
bumpers and tail fin in place.
6. Check the cotter pins on the tail pivot pin.
7. Check the torque on the tower mounting
bolts; the recommended value is 54 N.m (40
ft-lbs).
8. Check for cracks or loose hardware on the tail
boom and fin.
9. While descending the tower or before raising it,
inspect the following:
A. Check that the tower wiring is properly
secure.
B. Check all tower fasteners.
C. Look for any cracks in the tower structure.
D. Check the condition of the guy wire at-
tachments.
10. Check the connection on all ground rods and
hardware.
11. Inspect the surge arrestor(s). Replace if
there are signs of damage.
12. Restart the turbine.
13. Listen to the sound of the machine as it
speeds up. No mechanical sounds, such as a
"clunking" or "banging," should be heard. Al-
so watch for any new or significant vibration.
Some “growling” from the alternator is normal.
The turbine operation should be smooth.
14. Inspect the wire run, particularly all electrical
connections.
15. Check condition of all wiring connections into
and out of the PowerCenter.
Preventive Maintenance
We recommend that the bearings be re-packed
(re-greased) every 8-12 years. There are four
tapered roller bearings, two for the alternator and
two for the tower adapter. They are all the same
size (Timken L44643/L44610), except for the low-
er yaw bearing on XL.1’s shipped after September
2003. There are two bearing seals and we rec-
ommend that these seals be replaced when the
bearings are re-packed.
The strength of the blades, particularly at the root
(inner) end, may degrade over time due to flexure
and UV degradation of the fiberglass material.
The symptom of degradation is a reduction in
blade stiffness fore-and-aft. The blades have to
become very flexible in the fore-aft direction be-
fore there is any risk of tower strikes during se-
vere weather. We recommend that you check
blade stiffness about every 10 years and replace
the blades if they become extremely flexible.
PowerCenter Fuses
The PowerCenter has four fuses. If you blow
(fail) one or more of these fuses you may replace
them using the following specifications and parts
identifiers (P/N means part number):
Battery Fuse: 90-amps; Buss P/N JJN-90 or Little
Fuse P/N JLLN-90
Turbine Fuse: 70-amp or 75-amp; special order
because of the L-shaped mounting tabs, but you
can use a Buss P/N JJN-70 or Little Fuse JLLN-
70 by also installing 2 x M6 brass nuts per post
(before placing the new fuse) to accommodate the
straight tabs on the stock fuse.
Dump Load Fuse: 60-amp or 63-amp; Buss P/N
JJN-60L or JJN-60, or Little Fuse JLLN-60, using
2 x M6 brass nuts per post as described for the
Turbine Fuse.
Solar Fuse: 30-amp; Buss JJN-30L or JJN-30,
or Little Fuse JLLN-30, using 2 x M6 brass nuts
per post as described for the Turbine Fuse.