BRADEN PD12C Series Installation Maintenance And Service Manual page 14

TROUBLE
D
The hoist will not hoist the rated
load.
E
The hoist runs hot.
PROBABLE CAUSE
1. The hoist may be mounted on
an uneven or fl exible surface which
causes distortion of the hoist base
and binding of the gear train. Bind-
ing in the gear train will absorb
horsepower needed to hoist the
rated load and cause heat.
2. System relief valve may be set
too low. Relief valve needs adjust-
ment or repair.
3. Be certain hydraulic system tem-
perature is not more than 180 de-
grees F. Excessive hydraulic oil
temperatures increase motor inter-
nal leakage and reduce motor per-
formance.
4. Hoist line pull rating is based on
1st layer of wire rope.
5. Rigging and sheaves not operat-
ing effi ciently.
1. Same as D1.
2. Be certain that the hydraulic sys-
tem temperature is not more than
180 degrees F. Excessive hydrau-
lic oil temperatures may be caused
by:
A. Plugged heat exchanger.
B. Too low or too high oil level in hy-
draulic reservoir.
C. Same as D2.
14
REMEDY
Reinforce mounting surface.
If necessary, use shim stock to level
hoist. Refer to "Hoist Installation".
First loosen, then evenly retighten
all hoist mounting bolts to recom-
mended torque.
Check relief pressure as follows:
A. Install an accurate 0-4000 psi
(27,580 kPa) gauge into the inlet
port of the brake valve.
B. Apply a stall pull load on the hoist
while monitoring pressure.
C. Compare gauge reading to hoist
specifi cations. Adjust relief valve as
required.
NOTE: If pressure does not in-
crease in proportion to adjustment,
relief valve may be contaminated or
worn out. In either case, the relief
valve may require disassembly or
replacement.
Same as remedies for Trouble D1 &
D2.
Same as remedies for Trouble E2.
Refer to hoist performance charts
for additional information.
Perform rigging service as recom-
mended by crane manufacturer.
Same as remedies for Trouble D1.
Thoroughly clean exterior and fl ush
interior.
Fill/drain to proper level.
Same remedies as D2