Buildings focus: Should every dairy farm have a generator?

For many dairy farmers who did not have a generator, 2017 was a year to forget. Adverse weather conditions at crucial times throughout the year played havoc on farms across the country.

In addition, who can forgot ex-hurricane Ophelia? It left a trail of destruction and thousands of farms without power.

Since then, storms Dylan and Eleanor have also left farms in certain parts of the country flooded and without power. One thing that has become evident is the need for generators on farms – especially dairy enterprises.

Therefore, the question needs to be asked: Should every dairy farmer have a back-up generator? AgriLand recently visited Bradley Magnate – a company which produces tractor-driven generators – to see what they have available; how their generators work; the cost; and how business has been in 2017.

Roland Bradley of Bradley Magnate

Located on the Dublin Road, Portlaoise, Roland Bradley has been producing tractor-driven generators in Ireland since 2008. Before this, he imported the Magnate generator for the previous 30 years and sold some 7,000 units into the Irish market.

Bradley’s generators are assembled and packed in two different sites in Portlaoise. The company has dealers in Ireland, England, Wales, Scotland, Northern Ireland, Sweden, Denmark and various other places.

Commenting on the production operation here in Ireland, Bradley said: “We build the generators here in Portlaoise. Building the generator is actually the assembly of the unit.

“The alternators come from England, the gearboxes come from France and the control boxes are imported from Germany.

All the parts come to our production site where the finished unit is assembled, spray painted and tested.

The generators

There are two different types of tractor-driven generators that the company manufacturers – a portable unit that can be attached to the three-point linkage on a tractor or a bolted-down generator.

Bradley said: “The generators are the same, the alternators will be the same and what’s producing the electricity will be the same.

“The advantage of the PTO generator is that the tractor will always work. If the farmer has an engine-driven generator and doesn’t run it on a regular basis, it may not start when required.

Out of Ophelia, I have three generators going to farmers who previously had engine-driven generators.

“More than likely, there will always be a tractor available in the yard. Secondly, the tractor will have plenty of power so when you put it to the generator there will be perfect torque,” he explained.

Bradley outlined that, on a dairy farm, it takes very little to start the milking machine as it starts under no vacuum and is usually the first item turned on.

The main load arises when starting the milk tank compressors. They can draw up to five times their running load when starting. At this stage, other equipment such as scrapers and water pumps will have already cut in.

A quality generator will be capable of giving 200-300% surge for starting motors.

The company produces tractor-driven generators of different sizes to meet the needs of different farmers. The most popular generators are the 27KVA (one KVA is 1,000 volt amps) and the 33KVA (single-phase).

However, many of the larger farms are now converting to a three-phase generator, where 50KVA, 75KVA and even 110KVA units are in use.

A 33KVA tractor driven geneator with ‘fixed’ legs

“The ratio for a single-phase generator is 2:1, so if you have a 33KVA generator you will need a minimum of 60hp at the shaft to ensure that everything operates smoothly.

“The 27KVA generator is a very popular generator for the dairy men that have 10-12 unit milking parlours. There is also the 75KVA three-phase generator, which can supply enough electricity to run a rotary parlour.

Anything after a 12-unit milking parlour would probably need a 33KVA generator.

Bradley continued: “It is important to install a generator of sufficient size, that is matched to the incoming mains supply, so that all equipment on the farm can operate as normal and at the same time.”

How the generators work?

According to Bradley, the maximum amount of electricity the ESB allows the farmer coming into the farm is 125 amps. Therefore, there is not much point going bigger than this with a generator.

“A 33KVA generator will give 144 amps, protected by a 125-amp breaker and that matches exactly what the ESB is giving.

“Some farmers, if they have very big units – for instance a 30-unit parlour – would go to a 40KVA generator. But the bread and butter generator – the 33kVA – I have never seen them beaten,” he said.

Bradley insists that the product is extremely easy to use. The instructions are clear to see and once they are followed, he says, there will be no problems.

“If the farmer decides to totally over-rev the tractor, harm can be done. But it’s like any other piece of machinery; if it’s minded and the instructions are followed, there will be no issues,” he explained.

When there is a power cut, the farmer attaches the tractor to the generator via the PTO shaft. When the speed is correct, the changeover is made. The power will then come from the generator to feed the farm.


There is a unique speed control system on the generators which has been developed over 40 years. On the generator, whether it is portable or bolted down, there is a LED light system mounted on the wall. It works via frequency.

When the farmer brings up the speed of the generator, a light will start to flash. When it gets to 48 cycles, the light will become constant.

After reaching 52 cycles, it will start to flash extremely fast. The farmer can then ease back the throttle and when the light becomes constant again, it is perfectly set up.


The generators are run off a 540rpm (revs per minute) ‘box’. Once engaged, the farmer can bring the revs up to 430rpm on the clock. This will leave the tractor running at approximately 1,450rpm.

“This gives perfect torque which ensures the tractor is operating at a comfortable speed,” he explained.

He continued: “It is very important that the shaft is level. If the shaft is un-level, the voltage would be fine but there would be a flicker in the lights.

“Many men have rang me over the years and said everything is going perfect, but there’s a flicker in the lights and it’s driving me mad,” he laughed.

Bradley also commented on the different legs which can be fitted to the ‘fixed’ generator, stating: “We have different size legs where we can build up the generator if needs be. We have two guys with rotary parlours where the generators are 5ft off the ground.

“The maintenance on the generators is practically zero.  There’s two-to-three years warranty and we barely ever have any trouble.

However, nothing that was built mechanically will be trouble-free forever. But we are able to react quickly and fix the problem.

All maintenance procedures are clearly outlined on the generators. The oil should be changed every 500 hours or every five years and the generator should be kept in a dust-free environment.

“Generators do not like dust. They will take dampness sooner than they will take dust,” he explained.

The cost

“If the farmer goes for a 33KVA generator, which is the industry norm, on a set of legs, with a PTO shaft – the list price is €3,500 (excluding VAT). However, the farmer will end up paying around €3,200 (excluding VAT),” Bradley said.

If the farmer goes for the 33KVA [unit] on the three-point linkage, equipped with the PTO shaft, they are looking at €4,200 (excluding VAT). The bigger units, such as the 110KVA version, cost €5,500.

The smaller generators, such as the 20KVA units, cost €2,300 (excluding VAT). The 75KVA costs €4,700 (excluding VAT). However, VAT can only be claimed back on fixed generators.

A 75KVA generator (three-point linkage version)

“30 years ago, in one calendar year, we sold 1,000 generators. People think that the storms are only after coming now.

“However, Ophelia was the big one. It came up the middle of the country. The most inquires came from the counties outside of Kerry, Clare, Galway, Mayo, Sligo and Donegal. We have built a large quantity of generators since then.

“There is no doubt about it that the storms have helped my business. But the way I look at is, a farmer wouldn’t contemplate not having insurance on his/her farm and, in a nutshell, a generator is an insurance measure.

“My generators should last 50 odd years and if you buy it at the listed price, that works out at roughly a euro a day. However, I won’t except payment by a euro a day; but that to me is a solid investment,” he concluded.