Tuesday 4 August 2015

VRI & Irrigator Maintenance

In some areas it will not be long before pumps start up and irrigators are set in motion. So if you have not already done so you may want to consider a quick irrigator WOF check to make sure you get the best out of this critical piece of farm infrastructure. It may also be worthwhile evaluating if your irrigation system can be optimised or improved to save on costs such as water or energy.

Simple pre-season maintenance checks are able to be done by farm staff. A basic inspection while the irrigator is turned off can help assess if you will require service work to be carried out. It is recommended to park the pivot in an accessible position and ensure that the electrical isolator switch is tagged and locked to prevent accidental starting.

Every centre-pivot should be supplied with an operation manual which can come in handy, for most you will find this in the inside door of the main panel. Some manuals actually include recommended maintenance checks with instructions to show you how to carry them out. Whoever is carrying out the checks needs to be aware that centre-pivots are generally high voltage electrical systems, so leave all electrical checks to a qualified Service Technician. And if there is a need to work at heights make sure you have safe equipment to do so.

A walk up the length of the machine will allow you to assess any damage and parts requiring repair. Tighten, adjust or replace if possible, or note down so you can inform your Irrigation Dealer. Greasing of all the grease nipples as you go is highly recommended, important parts to maintain well-oiled are the pivot point, gear boxes and drive shafts. Checking that all moving parts around tower boxes are free and lubricated will help reduce problems for the upcoming season.

The uniformity of a centre pivot relies heavily on the correct sprinklers being fitted to each dropper, checking that the sprinklers installed match the sprinkler chart will allow your pivot to apply the specified application rates. Armed with a pole of some description you should be able to free any sprinklers that have become tangled over the truss rods.

It pays to check that the tyres are pumped up to their optimum pressure rating. As tyre pressure is critical not only for the life of the tyre, rim and gearboxes, but also the application rate of the sprinklers. Over or under-inflated tyres can apply higher or lower application depths than planned.

Once you have checked everything over with the pivot stationary, providing there are no required repairs, the next step is to run the pivot. This is ideally done when the soil is not too wet so that you dont create big wheel ruts, or worsen those that need attention. Wheel ruts significantly increase the load and wear on the drive train so should be dealt with when possible. GrowSmart Precision VRI technology can be used to reduce the spray onto the wheel tracks to help minimise wheel rutting.

Obvious checks while running the pivot are leaks. Some of these can be fixed with simple repairs such as replacing droppers, but others may require a call to your Irrigation Dealer to sort out. While walking the length of the irrigator listen for excessive vibration or noise that may indicate issues on the towers motors, gear boxes and drive shafts.

Some component wear will depend on water quality as high concentrations of iron, suspended solids and effluent solids or grit can increase damage and degradation to parts. A general check is recommended every season to ensure that worn sprinklers and pressure regulators are replaced to maximise the efficiency of the pivot. Common causes to check for are blockages or damages from knocks during the previous season, missing sprinklers and spray plates.

At the end of the irrigator remove the sand trap cap (with the irrigator turned off) and flush the system to get rid of any sediment build up, this is very often common in the overhang. If your water supply has a high level of sediment than it is recommended that this is done regularly.

Reducing the risk of breakdowns during the irrigation season will help avoid production loses due to downtime for repairs. Long term water and energy cost savings are also possible through the installation of technology such as variable rate irrigation, which can reduce nutrient leaching as well. If you would like more information on recommended maintenance checks for your irrigator, system calibrations or technology to improve water use efficiency call your local GrowSmart by Lindsay Dealer