English
Türkçe
The motor on your machine may belong to a brand that arrived from Europe twenty years ago; the manufacturer may have closed its local representation, spare-motor lead times may have stretched into months, and prices may have reached a point where you question the machine's value. The good news is this: replacing that motor with a unit from another manufacturer on a like-for-like basis is far easier than it is assumed to be. What makes this possible is the fact that low-voltage electric motors are produced worldwide to the same dimensional standard, the IEC standard. Two motors with the same frame number sit on the same base, carry the same coupling and bolt to the same flange, even if their brands differ. As HEM Motor, we have been manufacturing motors in Turkiye since 1979, and every year we accompany hundreds of plants as they replace their foreign-branded motors with equivalent units from our stock. In this article we explain, step by step, the standard-based logic behind a brand transition, the four criteria of equivalence, brand-specific exceptions, and the stock and service advantages you gain along with the switch.
The Foundation of Brand Independence: The IEC Frame Standard
The international standard that defines mounting dimensions in electric motors is the IEC 60072 dimensional system. This standard ties shaft height, foot-hole spacing, shaft diameter, key size and flange dimensions to the frame number. The shaft axis of a 112M-frame motor sits 112 mm above the foot base anywhere in the world; its shaft diameter, foot holes and flange dimensions are likewise fixed in the same table. The practical meaning of this is straightforward: in place of a 112M motor of German, Italian, Czech or Far Eastern origin, a HEM motor carrying the same frame number fits without any mechanical modification. It is the frame number on the nameplate, not the brand of the machine builder, that is decisive. Thanks to this standardisation, the belief that "that brand's motor cannot be replaced with another brand" is nothing more than a myth when it comes to low-voltage standard motors. Even on foreign nameplates that look hard to read, the frame number, power and speed lines are written in a universal form; equivalence is established from these three lines within minutes.
The Four Criteria of Equivalence
For a motor's counterpart from another brand to be considered "equivalent," four values must overlap. If these four hold, the motors are interchangeable; the brand, the year of manufacture and the country of origin no longer matter.
1. Frame number: the key to the mechanical match
The frame code on the old motor's nameplate (for example 132S) must be exactly the same on the new motor. If the frame is the same, the shaft height, shaft diameter, key and foot holes automatically match. The only point to watch is the size letter: 132S and 132M share the same shaft height but have different foot-hole spacing. A full match that also covers the letter means the bolts you removed go back into the same holes.
2. Power: same kW, same load capacity
The equivalent motor must carry the same rated power as the old one. On European brands' nameplates, power is always given in kW; on motors removed from old American-origin machines you may see HP, and during conversion it should be remembered that 1 HP is roughly 0.75 kW. The standard power steps (1.5, 2.2, 3, 4, 5.5, 7.5 kW...) are common to all manufacturers; for this reason, whichever brand it comes from, a counterpart for every power rating is found in stock.
3. Speed: pole-count match
The speed value on the nameplate tells you the pole count: the 3000 rpm class is 2-pole, the 1500 rpm class is 4-pole, the 1000 rpm class is 6-pole. The equivalent motor is selected at the same pole count. Between brands the rated speed may be written a few revolutions apart - one may show 1440, another 1455 - this difference stems from efficiency and slip and is not felt in the application; what matters is staying in the same speed class.
4. Mounting type and voltage: the language of the mount and the panel
If the old motor is B3 foot-mounted, the new one is selected as B3; if B5 flanged, then B5; if B35, then B35. Because flange dimensions are tied to the standard through the frame number, no flange mismatch arises in a brand change. On the voltage side, having the 230/400 V or 400/690 V winding arrangement identical to the old one ensures the starting scheme in the panel remains unchanged. We covered in detail how to convey these four criteria during the ordering process, together with error examples, in our article on nameplate matching before ordering.
Decoding Foreign Nameplates: Today's Equivalent of Old Codes
In a brand transition, the issue that wastes the most time is that the code systems on old nameplates differ from today's. On German motors left over from the nineties, the efficiency class is not written at all, or you see now-obsolete labels such as eff1/eff2; these have no one-to-one counterpart in today's IE classes, so the equivalent motor is selected from the current IE3 or IE4 class. On some old nameplates the mounting type is written merely as "V1" instead of IM B5, or in the old DIN notation; on others the voltage appears as 220/380 V - this is a sign of the period when the grid voltage had not yet been raised to 230/400 V, and today's 230/400 V wound motor is its direct counterpart. The lines for cos phi (power factor), Ins.Cl. (insulation class) and duty/Betriebsart (operating regime) are also written differently from language to language, but their meanings are shared. You do not need to do this translation work yourself: send the nameplate in whatever language and from whatever period it is, and we will derive its current counterpart with our equivalence table. Reaching today's stock code from a thirty-year-old nameplate is a routine task our sales engineers carry out every day.
Quick Field Verification: The Equivalence Test with Three Measurements
When the equivalent motor reaches you, run a three-minute verification round before you start mounting. The first measurement is shaft height: the distance from the foot base to the shaft axis of the new motor should be the same as the motor you removed - if the frame number is correct it is already the same, and this measurement is merely a confirmation. The second measurement is shaft diameter and key: the old coupling hub or pulley should slide onto the new shaft snugly but without forcing when pushed by hand; if it does not, it means the old shaft was machined off-standard. The third measurement is the connection holes: on a foot-mounted motor the four foot holes, and on a flanged motor the bolt-hole circle, should coincide with the old connection. If all three measurements hold, mechanical equivalence has been proven in the field; what remains is the electrical connection, rotation-direction check and thermal setting. This three-minute round brings any surprises that could occur on installation day to the table in advance, and prevents resources such as cranes and platforms from being hired in vain.
Transition Notes for Belt and Geared Drives
On coupled systems, equivalence is closed by the four criteria; on belt-and-pulley and geared drives, two additional notes deserve attention. On belt systems, if the old pulley is to be moved onto the new motor's shaft, compatibility of the pulley bore with the shaft diameter and keyway is sufficient; however, if the pulley has suffered groove wear over the years, the motor change is the ideal time to renew the pulley as well - a worn pulley puts unnecessary belt slip and side load on the new motor. On motors flanged to a gearbox, the gearbox input bore is machined to the motor shaft; as long as the frame number and flange type hold, the new motor seats directly into the gearbox. If the gearbox input flange has been machined specifically for the old brand, this exception is identified from a photograph and resolved with a flange adaptation.
Brand-Specific Exceptions: Where Care Is Needed?
The standard sets the rule; but some motors are produced outside the standard. To avoid surprises in a brand transition, check the exception groups below.
Motors specific to a machine builder
Some machine builders order motors from the motor manufacturer with a special shaft length, a special flange, or additional connection surfaces machined into the frame. Even if the standard frame code is written on these motors' nameplates, the shaft end or flange may deviate from the standard. Comparing the shaft length and flange dimensions against the standard table before removing the old motor reveals this exception. If detected, it is not unsolvable: as a manufacturer, we adapt the equivalent motor to your machine with shaft machining and special flange work.
NEMA-frame motors
On machines of American origin, the NEMA dimensional system is used instead of IEC; frame codes are written like 143T, 213T, and the dimensions are inch-based. A NEMA motor does not match an IEC motor hole-for-hole. In this case there are two routes: using an IEC motor with an adapter plate and coupling adaptation, or requesting an adapted solution by stating the shaft and foot dimensions. In both routes the dimensions must first be clarified; a "let's just fit it, it'll probably match" approach does not work in NEMA transitions.
Braked, two-speed and drive-integrated motors
If the old motor is braked, the brake voltage and brake torque enter the equivalence calculation; if two-speed, the winding arrangement (Dahlander or separate winding); if it has an integrated drive, the control architecture. These motors can also be replaced; however, alongside the nameplate, a photograph of the terminal-box connection diagram is also required. A significant portion of old two-speed motors are today replaced more economically with a frequency converter and standard motor pairing; we price both options according to your application.
Efficiency-class difference: reflected in the current value
A twenty-year-old motor sits below today's efficiency classes. The IE3 or IE4 motor that replaces it produces the same power with fewer losses; this means the nameplate current is somewhat lower than before. It does not affect the mechanical match, but the thermal-relay setting in the panel needs to be adjusted to the new nameplate current. A rise in efficiency class is the hidden gain of the transition: the same machine, the same work, a lower electricity bill.
The Commercial Gain of the Transition: Stock, Service and a Single Point of Contact
The brand transition should be seen not merely as an obligation but as a supply strategy. On foreign-branded motors, spare supply comes at a premium on two counts: lead time and exchange rate. The order the representative places abroad takes weeks, sometimes months; during this time your machine either stops or makes do with a loaner motor. When you start working with a manufacturer that produces and holds stock in Turkiye, both of these counts are closed at once: at HEM Motor the equivalent motor is ready in the warehouse, shipment starts within the day, and the price is settled under domestic conditions. The second gain is service: because you deal directly with the manufacturer, technical questions, warranty procedures and special-adaptation requests are answered without getting caught in an intermediary chain. The third gain is standardisation: when the different-branded motors at the plant are gradually consolidated under a single brand, your spare-motor count drops, your maintenance team works with a single type of terminal layout, and purchasing can sign an annual agreement with a single supplier. We addressed the cost comparison of turning to a new stock motor instead of hunting for the old brand's second-hand unit in an emergency, with figures, in our article on second-hand or new stock motor; the brand transition makes the "new and from stock" option in that article permanent.
The cost of postponing the transition: a spare that grows more expensive the longer you wait
Continuing with a motor of a brand whose local representation has weakened carries an unseen price: with each passing year, access to that brand's spare grows harder, its price rises and the lead time lengthens. While the machine itself would run for another ten years, the closing of the motor supply line forces the plant to decide at the worst possible moment - on the day of a breakdown. Drawing up the equivalence list today, before a breakdown arrives, reduces that day's decision to a two-minute phone call and shifts your bargaining power back from the emergency buyer to the planned buyer.
How the Transition Process Works in Practice?
The process is completed in three steps. The first step is identification: you send a photograph of the old motor's nameplate and of its connection on the machine; the equivalent model is determined from the frame, power, speed and mounting type, and if there is a situation falling into the exception groups, it is caught at this stage. The second step is the written quotation: the full definition of the equivalent motor, its stock status and lead time are conveyed to you the same day. The third step is shipment and commissioning: the motor is dispatched, the rotation direction and thermal setting are checked during mounting, and your machine runs. We also give plants making the transition the old-to-new nameplate matching record; thanks to this record, the next order is placed in a single sentence at the next breakdown. You can review our wide range of powers and frames on the standard electric motors page, and all product groups in the products section.
Frequently Asked Questions
When I fit a HEM motor in place of my European-branded motor, is my machine warranty affected?
If your machine is under manufacturer warranty, it is correct to notify the machine builder of the motor change; however, on machines whose warranty period has expired - which covers nearly all twenty-year-old motor changes - there is no such restriction. The HEM motor you fit comes with our own manufacturer warranty; the assurance on winding and workmanship is no less than what you would expect from a foreign brand. Moreover, your warranty counterpart is not a headquarters abroad but the manufacturer itself, here in Turkiye.
Will the torque the old motor delivers be the same as the new motor's torque?
The rated torque of two motors at the same power and the same speed is physically identical; torque is calculated from power and speed and is independent of brand. The difference may lie in the starting characteristic: new-generation rotor designs generally offer a higher starting torque, which is an advantage on hard-starting machines. On applications with a special torque need, such as cranes and crushers, if you state the application along with the nameplate, we verify the starting curve to the requirement.
I have forty motors of five different brands at my plant; should I replace them all at once?
It is not necessary, and we do not recommend it. The right strategy is a phased transition: you start with the motors that break down or run at low efficiency, fit the equivalent HEM model at each change, and update the old-to-new matching list. Within two or three years the fleet consolidates under a single brand on its own; during this time, common spare motors are determined for critical machines and a shelf stock is established. We draw up the equivalence list for your forty-motor inventory free of charge; as long as the list is in your hands, every breakdown is reduced to a stoppage as short as the shipping time.
Get a Quote
Whatever the brand, send a photo of your old motor's nameplate; let us quote the exact equivalent HEM motor the same day with stock and lead-time information. You can reach our sales engineers at +90 (532) 345 49 86 or convey your request through our contact us page. Do not wait for an overseas lead time; the equivalent motor is in Turkiye, ready on the shelf.
