When an electric motor arrives on site, the first critical step before installation is lifting it and moving it into place safely. Especially in medium and large-power cast iron body motors, the weight quickly rises to hundreds of kilograms; wrong lifting means both an occupational safety risk and hidden damage to the motor. In this practical guide we cover the motor lifting eyebolt (lifting eye/bolt), the weight by frame size, the sling and crane angle, the principles of safe lifting and the pre-mounting checks. Our aim is to help you protect both the crew and the investment while lifting the motor with a crane, and to carry out the right checks before commissioning.

Electric motor lifting eyebolt and safe crane lifting

What Is a Lifting Eyebolt (Lifting Eye) and How Is Its Capacity Understood?

The lifting eyebolt is the lifting point in the form of a ring or bolt screwed into the motor body. This eyebolt is designed only to lift the motor own weight; it is not used to lift additional loads such as a pump, reducer or pulley attached to the motor. The eyebolt capacity is proportional to the frame size and must be used within the limits set by the manufacturer. If there are multiple eyebolts, the load must be balanced across all of them and the slings connected symmetrically.

The integrity of the eyebolt must be inspected visually before every lift: if there is looseness, cracking, corrosion or bending, the eyebolt must not be used. In cast iron body motors the eyebolt seat is durable; however the corrosion risk rises in motors stored outdoors for long periods. On open field and corrosion, our article on corrosion protection in cast iron motors is valuable. For earthing and electrical safety, also see our guide on earthing and electrical safety.

Motor Weight by Frame Size

The weight of an electric motor is directly related to the frame size (IEC frame size) and the body material. While small-frame (IEC 56–90) motors weigh a few tens of kilograms, large-frame (IEC 250–355) cast iron motors can reach hundreds of kilograms, even tonnes. A cast iron body is heavier than an aluminium body; therefore the body material must also be taken into account when planning handling. Our article on frame sizes (IEC 56-355) weight and handling covers the frame-weight relationship in detail; for frame-power matching our guide on frame size and power matching shows the way.

Knowing the approximate motor weight at the ordering stage lets you select the right lifting equipment on site (crane, chain hoist, forklift). When deciding cast iron or aluminium, both the environmental conditions and ease of handling play a role; our comparison cast iron or aluminium body clarifies this decision.

Sling, Crane Angle and Load Distribution

The most often overlooked point of safe lifting is the sling angle. As the slings move away from vertical (as the angle widens), the load on each sling leg increases multiplicatively. Therefore the slings should be connected as close to vertical as possible, and wide-angle cross connection should be avoided. The load must be balanced relative to the motor centre of gravity; when lifted, the motor should not tilt or swing. Using slings and hooks of suitable capacity, and not exceeding the eyebolt capacity, is essential.

Safe motor lifting with sling angle and load distribution

Principles of Safe Lifting

To lift the motor safely, a few basic principles must be followed: the lifting area must be cleared, no one must stand under the load, lifting must be slow and controlled, and sudden movement avoided. When the motor is lowered, vibration and shock can damage the bearings; a soft and balanced lowering is therefore required. Bearings are sensitive to shock during lifting; for the bearing life and shock relationship, our article on bearing and bearing life is useful.

A sling must never be attached directly to the motor shaft; the shaft and key are sensitive mechanical elements and if damaged the coupling/pulley fit is impaired. For shaft, key and coupling fit, our guide on shaft diameter and key dimensions is important. For the transport and lifting plan of high-power motors, see our article on high-power motor supply above 90 kW.

Pre-Mounting Check: Is It Dry, Clean and Sound?

After the motor is moved into place, a few checks are essential before proceeding to installation. The motor must be confirmed dry and clean; if it took on moisture during transport or was stored for a long time, the insulation resistance must be measured. For the insulation check, our article on insulation resistance and megger test shows the way step by step. The shaft should be turned by hand to check that the bearings rotate freely, with no abnormal noise or binding.

In motors stored for a long time, the topics of moisture, bearings and commissioning become critical; our guide on electric motor storage and long-term keeping should certainly be read in this case. To catch any transport damage on delivery, our article on shipping damage check list is a practical inspection tool.

Forklift, Hoist or Crane: Which Equipment to Handle With?

The motor weight and the site conditions determine the choice of lifting equipment. Small-frame motors (a few tens of kilograms) can often be moved by hand or with a simple chain hoist; however medium and large-frame cast iron motors definitely require mechanical lifting. If a forklift is used, the motor must sit balanced on a sound pallet, the forks must be positioned relative to the motor centre of gravity, and the motor must be secured so it cannot slide. When lifting with a crane or hoist, the load must always be taken from the lifting eyebolt, paying attention to the sling angle.

During lowering on site, the motor feet (in B3 mounting) or flange (in B5 mounting) must sit balanced on the ground. The lifting and seating plan changes with the mounting type; for mounting types and connection faces, our guide on B5 or B14 mounting type selection helps. In vertically mounted motors (shaft down), lifting and seating require even more care; our article on vertical mounting (V1/V5) covers this special case.

Storage: If It Will Wait Before Installation

If the motor will not be installed immediately after arriving on site, correct storage conditions preserve the motor life. The motor must be kept in a dry, enclosed, vibration-free environment that does not take on moisture. In a motor left for a long time outdoors or in a humid store, the winding can absorb moisture, the bearing seats can corrode and rust can form on the shaft surface. In motors stored for a long time, turning the shaft by hand periodically prevents the grease film in the bearing from breaking down and a local pressure mark from forming in the seat.

If the storage period is long, insulation resistance measurement and visual inspection are essential before commissioning. On this, our article on electric motor storage and long-term keeping explains the steps of moisture, bearings and commissioning in detail. Planning which powers should be kept as spares for facilities is also important; our guide on critical spare motor list and stock planning shows the way on this. For the advantage of a cast iron body against corrosion in long storage, you can see our article on paint and cataphoresis coating.

Final Steps Before Commissioning

After mechanical installation is complete, the rotation direction, phase sequence and first-start checks are carried out. If these steps are skipped, a wrong rotation direction can cause damage in a pump or fan. Our articles on rotation direction and phase sequence and the commissioning and first-start checklist complete this process. For terminal connection and voltage selection, the guide on terminal connection (230/400V) should also be reviewed before commissioning.

For all motors you wish to source with the right frame size, the right weight and the right lifting plan, you can review our efficient electric motors product group and the HEM Motor home page. If you will lift and handle the motor together with a reducer, be sure to account for the extra load; for reducer solutions our worm gear reducers group can be considered.

Frequently Asked Questions

Can I also lift the pump or reducer with the motor lifting eyebolt?

No. The lifting eyebolt is designed only to lift the motor own weight. Lifting additional loads such as a pump, reducer or pulley attached to the motor with this eyebolt exceeds the eyebolt capacity and is dangerous. When lifting the complete assembly, separate lifting points and equipment of suitable capacity must be used to carry the extra load.

How can I find out the motor weight before ordering?

Motor weight depends on the frame size (IEC frame) and the body material (cast iron/aluminium). If you share the frame size and power information, we can help clarify the approximate weight and select the right lifting equipment on site. This matters for both occupational safety and the installation plan.

Why is the sling angle so important?

As the slings move away from vertical, the load on each leg increases; at very wide angles the sling force can rise well above the motor weight. This stresses both the sling and the eyebolt. Therefore the slings should be connected as close to vertical as possible, and the load distributed in balance with the centre of gravity.

Get a Quote

Contact us to safely source motors with the right frame size and with the weight and lifting plan clarified in advance. Share your need; let us determine the most suitable motor together with the frame size, approximate weight and installation details. Phone: +90 (532) 345 49 86 — or request a fast quote via our contact page.

Safe Handling and Pre-Mounting Checklist

  • Is the lifting eyebolt visually inspected (cracks, looseness, corrosion)?
  • Are the approximate motor weight and frame size known?
  • Is the lifting equipment (crane/hoist) capacity sufficient?
  • Are the slings connected near vertical, with the load balanced and symmetric?
  • Is the sling attached to the eyebolt and never to the shaft/key?
  • Is the lifting area clear with no one under the load?
  • Is the motor dry and clean; if it took on moisture, was insulation measured?
  • When the shaft is turned by hand, do the bearings rotate freely?
  • Are the rotation direction and phase sequence checked before commissioning?