Wide Sheave Stringing Roller for Cable up to 200mm Diameter
Once the cable passes about 120mm, the limit stops being the sheave
diameter and becomes the groove width. A narrow groove forces a
large cable to sit high in the roller, the contact patch shrinks to
a line, and the jacket takes a set at every roller. The 160x230mm
roller in this range opens the groove to 230mm so a 200mm cable
sits down in the profile with its full circumference supported.
Rated 5KN, 12.5kg, galvanized frame, ball bearing sheave, for cable
laying contractors and utility depots handling large power and
communication cable.
Range Data
| Item No. | Rated Load (kN) | Max Cable (mm) | Sheave (mm) | Weight (kg) |
| 21340 | 5 | 200 | 160 x 230 | 12.5 |
| 21339 | 5 | 150 | 140 x 160 | 3.5 |
| 21338 | 5 | 80 | 160 x 90 | 3.5 |
| 10228 | 5 | 100 | 120 x 130 | 2.7 |
Sheave size reads as outer diameter x groove width. The 160x230
unit is the one to specify for 200mm cable; the 140x160 and 120x130
units cover the mid range, and the 160x90 is the narrow groove
roller for smaller cable that has to run fast without wandering.
Why Groove Width Decides for Large Cable
Contact area: a cable 200mm across sitting in a 230mm groove contacts over a
wide arc, so the load spreads along the jacket instead of
concentrating at two shoulders.
No jacket set: wide support stops the cable taking a permanent bend at each
roller, which is what causes the flat spots crews find after a long
underground pull.
Straight tracking: a wide groove lets the cable run without climbing a side flange,
so rollers can be spaced further apart along the trench without the
cable walking out.
Ball bearing sheave: the sheave turns with the cable instead of being dragged, which
matters when a 12.5kg roller is carrying a heavy cable at low
tension.
Roller Configurations in the Same Range
The same sheave family is supplied as straight rollers for trench
runs, corner rollers for direction changes at manholes and duct
entries, and triple roller assemblies where three rollers cradle a
cable through a bend. Specify by cable diameter first, then by
configuration, then by mounting: most units are supplied with a
hook or a plate base, and the base is chosen against the trench
edge or the duct frame.
Setting Rollers in a Trench
Keep roller spacing so the cable never touches the ground between
rollers, align the rollers with the pull direction rather than the
trench wall, and at a corner use a roller with enough groove width
that the cable cannot ride up the outer flange. Check the cable
entry angle into each duct: a sharp entry will scuff the jacket no
matter how good the rollers are, so a bell mouth or a second corner
roller is often the cheaper answer.
Inspection
Spin the sheave before each pull and reject any unit with grit in
the bearing or a flat spot from a drop. Check the groove for burr
where a cable has previously ridden a flange, and check the frame
welds and base plate at every site move. Sheaves and bearings are
replaceable service parts.
Packing and Supply
Packed in plywood cases with the sheave protected. Monthly capacity
around 1000 pieces, delivery 7 to 15 days, minimum order 1 piece,
OEM marking and packing marks to the buyer drawing.
Frequently Asked Questions
Can the 160x230 roller take 250mm cable? No, the groove is sized
for 200mm; a wider unit is made to order.
Is a nylon sheave version available? Yes, nylon sheaves are
available for cable that must not be marked.
Which roller for a 90 degree duct entry? A corner roller of the
same sheave family, set square to the duct axis.
