How to manage shed maintenance during the summer

Technical guide: Preventive maintenance for ACF circulators, EWS and EWD extractors, and electric motors

July and August are the months when a ventilation system works at its peak. They are also the months when it is most likely to stop. This is no coincidence; the summer heat amplifies everything. Temperatures inside the warehouse rise, motors struggle to dissipate heat, belts worn from winter use are reaching their limits. A component that was showing signs of weakness in March stops working in August. And in many sectors , stopping ventilation means stopping production .

The most cost-effective way to avoid this is a systematic check before the heat arrives, not during it. The following is the protocol we apply to our customers’ systems: three interventions, in order of priority, on the components most at risk during the hot season.

Cleaning the blades and protective nets on ACF circulators

The ACF circulator operates continuously and is responsible for moving large masses of air within the building, counteracting thermal stratification that in summer can create temperature differences of up to 10–15°C between the floor and ceiling. To do this efficiently, the fan must rotate freely and in balance.

The problem is that the blades of an ACF, which has been operating from October to April, accumulate dust, particulate matter, flour, or light shavings, depending on the sector. Even a thin, unevenly distributed layer introduces an imbalance that results in vibrations. Vibrations wear out the bearings. As summer temperatures rise, those already stressed bearings fail sooner.

What to do

Turn off the circulator and wait for the fan to stop. Remove the protective mesh and clean each blade individually with a dry cloth or low-pressure compressed air. On the 18″ and 26″ ACFs, the fan access system is designed for this purpose, and disassembly of the casing is not necessary.

Check the blades for warping, cracks, or signs of wear on the edges. Also check the mesh itself, as a partially clogged mesh reduces airflow and increases noise, which on the ACF 18 is already limited to 65 dB under normal conditions. If it sounds louder than usual, the cause is often a dirty or warped mesh.

Before closing, rotate the fan manually; it should turn freely and without irregular resistance . If you hear a slight scratching or a rubbing sensation, the bearing needs to be replaced.

Checking the belt tension on EWS pullers

The 42″ and 53″ EWS extractors are belt-driven. They are designed to handle large airflows in large warehouses. The most powerful versions of the 53″ EWS model move up to 44,500 m³/h at zero pressure, making them the benchmark for extraction in large agricultural and industrial environments.

The belt is the component that requires the most attention before summer. A loose belt slips on the pulley, dissipates energy in the form of heat, and produces noise. A belt that is too tight overloads the motor and shaft bearings. In both cases, performance decreases and mechanical wear accelerates.

What to do

With the machine turned off, press the belt at the center point between the two pulleys. The correct deflection is approximately 2% of the distance between the pulley centers. If it sags more, it is loose. If it is stiff and does not sag, it is too tight.

On EWS, the belt is pre-tensioned and the motor fastening system is designed to facilitate adjustment. Check the surface condition of the belt anyway . Transverse cracks, frayed edges, or excessive polishing of the sides are signs that the component is close to failure. Replacing it before it fails costs much less than an unplanned machine downtime in the middle of summer.

Also check the pulley alignment; a ruler placed on the outer faces is sufficient for a quick check. Misaligned pulleys wear the belt asymmetrically and produce vibrations that are transmitted to the bearings.

One last thing. If your system has EWD extractors in the 26″ to 37″ sizes, you don’t have any belts to check because they operate with direct drive. On these models, however, check the patented flap opening system , which guarantees full opening at just 40% of the nominal speed, but only if the flaps are clean and the rotation pins are not blocked by deposits or oxidation.

Thermal control of electric motors

The electric motors mounted on ACF, EWD, and EWS are high-efficiency IE3 motors, compatible with inverters for speed regulation. They are designed for continuous operation, but have a specific thermal limit that is tested differently in summer than in the colder months.

The reason for overheating is simple: the motor’s cooling air comes directly from the outside environment. If the temperature in the building rises from 20°C to 45°C, the motor is already in trouble. If we then factor in the dust that settles on the cooling fins throughout the year, the result is excessive heat buildup that never emerges in winter but becomes noticeable in summer.

The basic rule of thumb is that for every 10°C above the ideal operating temperature, the lifespan of the electrical insulation is halved. Although the most common motors can withstand temperatures up to 155°C, staying below 130°C is the best option to ensure a long machine life.

What to do

Clean the engine’s cooling fins and ventilation grille. This is the simplest and often most overlooked task. A dusty engine cannot dissipate the heat generated internally.

Check the operating temperature with an infrared thermometer, pointing it at the engine casing away from the bearings. If the engine is hotter than usual, check three things:

• Does the load match the size of the motor installed?
• Is the supply voltage within tolerance?
• Are the three phases balanced?

A 5% phase imbalance can result in a temperature rise of more than 25%.

If you’re using an inverter for speed control on your system, also check that the minimum frequency setting doesn’t force the motor to run too slowly during peak hours. At low speeds, the internal cooling fan becomes less effective, and the motor tends to overheat.

Three checks, a season without stops

Cleaning the blades, tensioning the belts, and checking the motors’ thermals. On a standard system, this takes two or three hours. The downtime they prevent, in the middle of summer, can cost tens of thousands, in addition to the collateral damage to production, personnel, and facilities.

If you manage a warehouse with ACF circulators, EWS, or EWD extractors and haven’t yet had a seasonal inspection, now is the perfect time, before temperatures really rise. We have the spare parts in stock in Fisciano and can support you from the technical inspection to delivery.