When buying an IE4 motor, the focus is often on power, speed and efficiency class; yet how well the motor fits your panel and cable route is just as important. The position of the terminal box and the cable entry direction are a critical detail that makes connecting the motor in the field either easy or difficult. A terminal box arriving in the wrong orientation can force you to route the cable around unnecessarily, use extra glands and trunking, and even put the IP protection at risk. By contrast, when the correct box position and entry direction are specified at the order stage, the motor connects to the panel cleanly, safely and tidily on the first try. In this article we examine the terminal box position (top/right/left) on an IE4 motor, the cable entry and gland direction, the rotatable box option, the panel-cable route, IP protection and what should be specified when ordering. (This article makes no fixed-price or numerical promises; the goal is to explain the right approach.)

Terminal box position and cable entry direction selection on an IE4 motor

Why Does the Terminal Box Position Matter?

The terminal box is where the motor's supply cable connects and the winding leads are brought out. This box is standardly located on top of the motor, but on many IE4 motors it can also be positioned on the right or left side. The box position determines from which direction the cable reaches the motor and along which route it reaches the panel. If the panel is on the right of the motor and the box is on the left side, the cable must be routed around the motor; this creates problems for both aesthetics and safety.

The correct box position shortens the cable route, eliminates unnecessary bends and speeds up installation. It also extends cable and gland life by preventing the cable from being stressed with sharp turns. We covered how to choose the terminal box orientation and cable entry side relative to the panel for the general motor range in detail in the terminal box orientation and cable entry side article. You can find the relationship of the terminal box and cable connection with IP protection in cast iron frame motors in the terminal box and cable connection in cast iron motors article.

Top, Right and Left Position Options

On most IEC-standard IE4 motors, the terminal box can be on top (standard), on the right or on the left relative to the foot position. Which position is suitable depends on how the motor is placed on the machine and on the panel-cable route. The top position is where the terminal box is most easily accessible and where the least water accumulates; this is why it is preferred in most applications. However, if the motor is mounted in a narrow channel or under other equipment, a side position can provide easier access. Another example is when the motor is placed close to a machine body; here a top-position box can clash with the machine and leave no room to connect the cable. In such cases the side position is the only practical solution.

A point often overlooked in position selection is that when the motor later needs to be removed for maintenance, the box and cable must not obstruct this operation. The terminal box should not block service points such as the motor's fan cowl, lifting eyebolt or bearing cap. A well-planned position eases both initial installation and lifelong maintenance.

Here the mounting type (B3 foot-mounted, B5 flange-mounted, B35 combined) and the box position must be considered together; because the motor's mounting arrangement determines which way the terminal box faces. For correctly reading the mounting code (IM B3, IM B5, IM V1) and specifying it when ordering, the IM mounting code reading guide provides direct guidance. We covered the box position and preventing water accumulation in vertical-mounted (V1/V5, shaft-down) applications in the vertical-mounted motor selection article.

Cable Entry Direction and Gland Selection

As important as the box position is the direction from which the cable enters the box. The cable entry (gland/cable hole) is on a side surface of the box and, since it is usually rotatable, can be oriented so the cable enters from below, the side or above. In outdoor and humid environments it is preferable for the cable to enter from below; because this prevents water droplets from running along the cable and seeping in through the gland (the siphon effect). Selecting the gland of the correct type and at the correct tightening torque is critical for both mechanical grip and IP protection. A wrongly sized gland does not grip the cable sufficiently; this opens the door to both mechanical loosening and the ingress of water and dust. Unused cable entry holes must always be closed with a blanking plug (of suitable IP class); a hole left open nullifies the motor's frame IP protection.

For cable cross-section, lug selection, terminal tightening torque and the correct gland, the electric motor cable connection and cable lug selection article is a comprehensive resource. You can find the cable cross-section, fuse and contactor selection according to the IE4 motor's rated current via its asynchronous equivalent in the rated current cable, fuse and contactor selection article. The terminal connection and voltage selection article explains the relationship of the IE4 motor's terminal connection with star/delta bridging and voltage selection.

Cable entry direction, gland and rotatable terminal box on an IE4 motor

The Advantage of a Rotatable Terminal Box

On many IE4 motors the terminal box can be fixed by rotating it to 4 directions (in 90-degree steps). This provides great flexibility in the field: the same motor, regardless of which side the panel is on, can have its box rotated to turn the cable entry to the right direction. The rotatable box offers stocking and installation ease especially in plants where many motors connect to panels in different orientations; a single motor type fits different layouts.

However, rotating the box must be done carefully regarding the correct ordering of the winding leads and the correct seating of the gasket; otherwise the IP protection can be compromised. After rotating the box, checking the direction of rotation and phase sequence prevents errors at commissioning. You can find the direction of rotation and phase sequence check in the rotation direction and phase sequence article, and all pre-commissioning checks in the incoming and acceptance inspection article.

Panel-Cable Route and IP Protection

The terminal box position and cable entry direction must be considered as integral with the plant's panel-cable route. A well-planned route makes the cable trunking, gland direction and box position compatible with one another. This shortens installation time, prevents excess cable and eases access during maintenance. Especially on lines with many motors, standardizing box positions greatly eases the maintenance team's work. A very winding cable route is not just an aesthetic problem; excess cable length both increases cost and enlarges voltage drop. The correct box position prevents these issues from the start by bringing the cable to the panel by the shortest and tidiest path.

IP protection is decisive in this equation. The IP class of the terminal box and gland is as important as the motor's frame IP class; because water and dust often enter through the weakest link, namely a poorly sealed cable entry. IE4 motors offer IP55 protection as standard; IP65/IP66 can be requested in harsher environments. You can find IP protection class selection in detail in the IP55, IP65, IP66 protection class selection article, and for hygienic plants requiring high-pressure washdown in the IP69K washdown and hygienic plant article.

Terminal and Grounding in VFD-Driven IE4 Systems

IE4 motors are frequently run with a variable frequency drive (VFD). In drive-fed systems the terminal box is a critical point where not only the power cable but also the shield connection of the shielded cable and the grounding are correctly made. Terminating the shield of the shielded cable in the box with a 360-degree (circumferential) EMC gland reduces bearing currents and electromagnetic interference. So in VFD-driven IE4 systems the terminal box must be chosen and connected correctly not only for position but also for EMC.

We covered the correct setup of grounding and EMC in a VFD system in the motor grounding and EMC article, and the VFD and harmonic-induced bearing current risk and protection in the VFD and harmonic bearing current article. The frequency drive with asynchronous motor article explains when a frequency drive is needed in the IE4 efficiency range.

Standard Box Options in the IE4 Efficiency Range

IE4 super premium motors are offered in a wide power range (0.25 kW – 355 kW) and in different mounting types (B3, B5, B35). In this range the terminal box options are usually standardized: standard top position, side position on request, rotatable box and different gland entry directions. Specifying the right option at the order stage prevents surprises and delays in the field. The terminal box option does not change the motor's efficiency class or mechanical connection dimensions; it only determines how the cable connects. This distinction is important: choosing the right terminal option eases installation without compromising the motor's performance. So specifying the box position when ordering is not an "extra" but a basic step ensuring that a correct motor connects correctly to the panel.

In multi-country or export projects, because different plants may have different panel layouts, the terminal box position and entry direction can vary from project to project. In such projects, defining a standard box position and preferring a rotatable box simplifies the logistics and installation process. We covered settling these details in advance in project-based bulk motor supply in the project-based bulk motor supply article.

We covered that frame, foot and shaft dimensions do not necessarily stay the same when transitioning to an IE4 motor in the mechanical compatibility in IE4 transition article; you can find the IEC connection dimensions in equivalent selection in the equivalent selection and IEC dimensions article. We covered nameplate reading and verifying all fields before ordering in the nameplate and label reading guide. For fast supply from the IE4 stock range, the IE4 stock range article is useful. You can reach all our IE4 solutions and product range via our homepage.

Frequently Asked Questions

Do I have to specify the terminal box orientation when ordering?

The standard top position fits most applications; but if the motor is mounted in a tight space, under other equipment, or the panel is on a particular side, specifying the box position and cable entry direction when ordering eases installation. If you do not specify, the standard position is shipped; if there is a rotatable box in the field it can still be adjusted, but the cleanest solution is to clarify it at the order stage.

Can I rotate the terminal box myself in the field?

On many IE4 motors the terminal box can be rotated in 90-degree steps. During rotation, attention must be paid to connecting the winding leads correctly, seating the gasket correctly and preserving the IP protection. After rotating, do not forget to check the direction of rotation and phase sequence. If unsure, seeking technical support is advised.

Should the cable entry be from above or below?

In humid and outdoor environments it is preferable for the cable to enter from below; this prevents water droplets from running along the cable and seeping in through the gland. In clean and dry indoor environments the direction is more flexible and can be set according to the panel route. In all cases, a gland of the correct type and tightening torque secures the IP protection.

Get a Quote

Let us clarify together your IE4 motor order with the terminal box position and cable entry direction suitable for your panel and cable route. To determine the right options, you can reach us at +90 (532) 345 49 86 or create a request via our contact page.

Purchasing and Selection Checklist

  • Determine the panel's position relative to the motor (right/left/top) and choose the box orientation accordingly.
  • Clarify the mounting type (B3/B5/B35) and IM mounting code when ordering.
  • Specify the cable entry direction (up/down/side) according to environment and route; entry from below in humid environments.
  • Select the gland type and quantity according to the cable cross-section and IP class.
  • Evaluate the need for a rotatable box (standardization on multi-motor lines).
  • Determine the IP protection class according to the environment (standard IP55; IP65/66 in harsh environments).
  • In a VFD system, plan the shielded cable shield and EMC gland/grounding.
  • After rotating the box, check the direction of rotation and phase sequence at commissioning.