Products
Centre Pivot Specifications
Pivot
The Pivot legs are manufactured from 90x90x8 angle iron and the horizontal cross braces from 70x70x6 angel iron. The complete pivot is available as a fixed structure or with towable skids. A 4-wheel towable option for daily towing is an optional extra. A 100mm tractor mount quick tow pivot for the one tower water driven machine can also be utilised for a one or two tower electric quick tow pivot.
Spans
Coupling between larger diameter spans is by means of an external ball and socket joint that does not transfer operating loads from one tower to the next. The flexible rubber boot can be replaced without disengaging towers and without any lifting equipment. See table for complete range of lengths and diameters.
Trusses and Truss Rods
Truss supports and spreaders are made from 38 x 2,5mm structural pipe while the truss rods are 20mm in diameter.
Drive Unit Base Beam
1,5m long 165mm x 3mm pipe (5,9m x 165mm x 3,5mm on the high profile models) with motor, gearbox and leg bracket welded on.
Drive Unit Legs
Four 100x75x6 legs with 20mm Ö and two 38 x 2,5mm diagonal braces form an extremely ridged connection between base beam and span.
Drive Train
The 0,56kW 40:1 or 1,1kW 30:1 three phase 400 Volt 50 Hz motor-gearbox unit has a fully enclosed irrigation duty motor, mounted at the centre of each base beam.
The 50:1 wheel gearboxes are fitted with 57,15mm output shafts. All shafts have double lip oil seals with external seal savers. A full cycle expansion chamber with bellows-type expansion diaphragm is standard on all gearboxes.
Coupling drive shafts to motors and gearboxes is by means of no maintenance, precision die cast aluminium, high torque, driveline universals. The self aligning rubber insert allows for softer starts and stops. This feature is critical in prolonging gearbox life.
Pivot Control
The standard system is a manually controlled main panel with push button and toggle switches. Various electronic options are available to automate this system. Although proven very reliable, all electronic panels are backed by a mechanical system and are made up of modular panels for easy upgrading and maintenance to keep you going.
The electrical system is designed to operate from a 400 Volt 50 Hz, three-phase, four wire power source with built in 380/230/24V step down transformer for the 230V single phase control circuit.
The minimum and maximum recommended voltage at the last drive unit is 380 and 420 Volt respectively.
Wiring
Main power leads: 4mm2 copper cables
Control power leads: 1,5mm2 copper cables
Speed Control
Speed of the system is controlled by stopping and starting the last tower for predetermined periods of time. This percentage timer setting is done at the main panel. Electronic panels have a direct mm application dialling feature as standard on the "wet" setting.
Electrical Switches
Heavy duty micro-switches and contactors at each drive unit control the forward and reverse circuits. A second micro-switch provides alignment safety shutdown. All control equipment mounted in a drip-proof tower box.
Over-Watering Safety
A timer in the second last tower box shuts the system down if it fails to move after a pre-selected time.
Run Light
Mounted at the lat drive unit. Indicated when system is in operation.
Protective Coating
All Structural components are galvanised in accordance with SABS 763 1977 specifications.
Bolts and Nuts
All bolts and nuts are grade 8,8 and are electro galvanised. Locknuts are used on all truss assemblies.
Height of overhanging supports:
6,90m with standard tyres.
Overhanging from socket to wheel:
0,90m centre centre. |
