Centre Pivots

Pivot

The pivot structure with its three internally mounted cross braces per side (four on the high profile models) provides more than enough strength and durability to handle radial, vertical and horizontal loads.

The stainless steel cable conduit seals and low cost, extremely durable riser pipe seal require virtually no maintenance.

Coupling to the first tower is by means of a standard pivot flex (Not an optional extra).

The system is controlled by SA designed and built mechanical and electronic control panels making use of standard 230 Volt control circuit. All electronic panels are backed by a mechanical system and have modula panels for easy upgrading.

 Span & Overhang

The spans are probably the strongest on the market in SA. This is achieved without adding extra weight and by making use of up to eleven pipe trusses per 57.6m span.

Truss rods are 20 mm in diameter and per tower consists of four tower truss rods with 20 inter long truss rods and 4 inter short for the 64m span; 20 inter long truss rods for the 57m span; sixteen inter long plus two inter short for the 51m and 12 interlong plus four inter short for the 45m span.

Each of the four overhang pipes has its own set of support cables with three sets of back cables for the various span lengths.

All pipes are 6,4m in length irrespective of the diameter and are thus easily transported and installed.

Drive Unit-Base Beam

The standard 4,5m long heavy duty base beam (5.9m for the high profile models) ensures stability over uneven terrain and during windy conditions. Drive unit legs are made from 100x75x6 angle iron and reinforced with horizontal and diagonal braces.

The ball & socket joint between large diameter spans, prevents operating loads from being transformed from one tower to the next.

All in all the Senter360 pivot was designed and is built to last.

System Truss Locations

System Span Detail

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.

Collector ring end gun control/auto stop

Active/deactivate end gun from collector ring at pivot point or stop system at predetermined point.

End of field stop

Allows the system to be stopped at present positions such as obstructions (Activation unit is mounted on the last drive unit).

End of field stop/auto reverse

System automatically goes into reverse at preset positions.

Low pressure shut-down

Shuts the system off if a water pressure loss occurs.

Pressure start

Starts the system automatically when water pressure has reached a predetermined level at the pivot.

Ap-protection

Shuts the pumping unit off if the system fails to move after predetermined time. For operation without cable connection, power for pump and pivot must come from the same electrical supply point.

Standard Pivot inlet

Galvanised flanged pipe and bends connect underground mainline to pivot inlet flange. Provision made for fitting electrically or hydraulically operated valve.

Wheels and tyres

The standard tyre is a 13.6×24, mounted on a 12×24 galvanised rim.

Four wheeler

Available for 152mm and 165mm spans up to seven spans.

High speeds motors

The standard motor is a 0,56kW; 40:1; 35 RPM unit. A 1,1 kW; 30:1; 48 RPM motor for high speed operation is available.

Electronic control panels

The basic APT electronic panel, PAT part circle electronic panel, and PRO full networking electronic panel, are available with radio or cell phone communication as an optional extra.

Control Panel Options

Please note:

• Many of the options may vary with new models being updated regularly.
• Make sure that you order the panel you prefer with the specific options you need.
• The above panels do not necessarily include all the marked options as standard.
• The APT and PAT panels can also be connected to a network system.