DRG Motor offers four models in its cast iron housing with a 225 mm shaft height: the 225S frame carries only the DRG-225S-4 (37 kW, 4-pole), while the 225M frame carries the DRG-225M-2 (45 kW, 2-pole), the DRG-225M-4 (45 kW, 4-pole) and the DRG-225M-6 (30 kW, 6-pole). The frame is shared, the shaft is not: on 225M the 2-pole motor has a 55×110 mm shaft, the 4- and 6-pole motors a 60×140 mm shaft. Common dimensions are H 225 mm, A 356 mm, C 149 mm and a B5 flange with P 450 mm.

Grey DRG three-phase cast iron electric motor – illustrative image for 225S and 225M frame models

All four models belong to the three-phase asynchronous electric motors range; you can compare their product pages and other frame sizes in the online motor shop. Motors in this power band usually drive fans, pumps, crushers, conveyors and compressors — machines that are hard to modify on site — so the most common ordering mistake is choosing by kW before checking the shaft and foot dimensions.

Which DRG models use the 225S and 225M frames?

The first difference between 225S and 225M is the number of models. In 225S, DRG's only model is the 37 kW 4-pole motor; there is no 2-pole or 6-pole DRG model in this frame. The 225M frame has three models, and two of them share the same rating: 45 kW is built on 225M in both 2-pole and 4-pole versions. The 30 kW 6-pole model also uses 225M. All models have cast iron housings and 400/690 V (Δ/Y) connection.

ModelPowerSpeed class / rated speedShaft D×E (mm)
DRG-225S-4 (225S frame, 4-pole)37 kW / 50 HP1500 / 1485 rpm60×140
DRG-225M-2 (225M frame, 2-pole)45 kW / 60 HP3000 / 2965 rpm55×110
DRG-225M-4 (225M frame, 4-pole)45 kW / 60 HP1500 / 1485 rpm60×140
DRG-225M-6 (225M frame, 6-pole)30 kW / 40 HP1000 / 980 rpm60×140

"1500 rpm" and "3000 rpm" describe the speed class (synchronous speed); the second value in the table is the nameplate speed. The DRG-225M-4, for example, is in the 1500 rpm class and its nameplate reads 1485 rpm.

Pole count changes the shaft: 55×110 versus 60×140

This is the main trap with the 225M frame. The DRG-225M-2 and the DRG-225M-4 share the frame, the 45 kW rating and the foot dimensions, yet they carry different shafts:

  • 2-pole (DRG-225M-2): shaft 55×110 mm, key 16 mm, overall length L 819 mm.
  • 4- and 6-pole (DRG-225M-4, DRG-225M-6): shaft 60×140 mm, key 18 mm, overall length L 849 mm.

The shaft diameter grows by 5 mm and the shaft length by 30 mm; the 30 mm difference in overall length comes entirely from the shaft. The reason is torque: a 2-pole motor delivers the same power at roughly twice the speed, so its shaft sees less torque. In practice, replacing a 2-pole 225M with a 4-pole 225M means the coupling hub or pulley bore has to change from 55 mm to 60 mm, and the machine needs room for a shaft 30 mm longer. The other way round, a 60 mm bore will not fit a 55 mm shaft. Shaft, key and coupling relationships are covered in motor shaft diameter, key and coupling standards, and shaft diameters for every rating are listed in the motor shaft diameter by kW table.

The 4-pole 225S also has a 60×140 mm shaft, so the 4-pole 225S and the 4-pole 225M use the same shaft size.

225S versus 225M: lengthwise foot hole spacing

The S and M letters in the IEC frame code indicate housing length. In DRG data, 225S and 225M share shaft height H 225 mm, transverse foot spacing A 356 mm, C 149 mm and foot holes 4–Ø18.5 mm. The dimension that changes is B: 286 mm on 225S and 311 mm on 225M. Those 25 mm move the rear pair of holes on the base. Going from a 4-pole 225S to a 4-pole 225M keeps the shaft but requires new holes in the motor base or an adapter plate; the 4-pole 225M is also 25 mm longer (L 824 → 849 mm).

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Foot-mounted B3 dimensions for 225S and 225M

The table below shows the B3 dimensions from DRG product records. The 6-pole DRG-225M-6 has the same dimensions as the 4-pole 225M, so both share one column. Values in bold differ between columns.

Dimension (mm)225S – 4-pole225M – 2-pole225M – 4/6-pole
H – shaft height225225225
A – foot hole spacing (across)356356356
B – foot hole spacing (lengthwise)286311311
C – shaft shoulder to foot hole149149149
K – foot holes4–Ø18.54–Ø18.54–Ø18.5
D – shaft diameter605560
E – shaft length140110140
F – key width181618
AC – housing diameter446446446
AD – axis to terminal box top322322322
L – overall length824819849

All four models list 6313-C3 bearings and a 2 × M50×1,5 cable entry. For the differences between mounting arrangements see motor mounting types B3, B5, B14 and B35; drawing files are available on the 2D technical drawings and 3D technical drawings pages.

B5 flange dimensions: two separate rows for 225M

In DRG's B5 large-flange catalogue table, 225S has a single row while 225M has two: one for 2-pole and one for 4-pole and above. The flange itself is the same in all three rows: outer diameter P 450 mm, spigot diameter N 350 mm, bolt circle M 400 mm, hole diameter S 18.5 mm, spigot depth T 5 mm. What differs is again the shaft and the lengths that depend on it.

B5 dimension (mm)225S – 4-pole225M – 2-pole225M – 4/6-pole
P – flange outer diameter450450450
N – spigot (pilot) diameter350350350
M – bolt circle diameter400400400
S – flange hole diameter18.518.518.5
T – spigot depth555
LA – flange thickness202020
D×E – shaft60×14055×11060×140
F – key width181618
G – shaft to key-seat bottom534953
DH – shaft end threadM20×42M20×42M20×42
LB – flange face to rear end684709709
L – overall length824819849

So for a B5 flanged 225M, quoting the flange is not enough: with the same flange the shaft is 55×110 mm on 2-pole and 60×140 mm on 4/6-pole. Flange values for every frame are in the B5 motor flange dimensions table, and the difference between the FF large flange and the small flange is explained in B5 and B14 flange FF/FT difference.

The B14 small-flange table is not part of the DRG catalogue, so we do not give B14 or B34 dimensions for the 225 frame. If you need such a connection, send the existing flange's outer diameter, bolt circle, spigot diameter and thread size on WhatsApp and we will check it.

Current and torque: different load behaviour in the same frame

The torque your machine needs selects the model as much as the frame does. Torque values in the table come from DRG records; the last column is our check with M = 9550·P/n (P in kW, n = nameplate speed in rpm).

ModelCurrent at 400 V (A)Rated torque (Nm)Check: 9550·P/n
DRG-225S-466.1237.99550·37/1485 = 237.9
DRG-225M-276.8144.99550·45/2965 = 144.9
DRG-225M-480.2289.49550·45/1485 = 289.4
DRG-225M-656.2292.39550·30/980 = 292.3

Notice that the 30 kW 6-pole DRG-225M-6 has a slightly higher rated torque than the 45 kW 4-pole DRG-225M-4 despite its lower power (292.3 Nm vs 289.4 Nm). At the same 45 kW, the 2-pole model delivers 144.9 Nm, which is why the thinner shaft is sufficient. For cable and protection sizing, use the 400 V current together with the motor current chart and the motor cable size calculator.

Dimensions to confirm before ordering

Working through these checks in order greatly reduces the risk of ordering the wrong pole count or the wrong frame length for a replacement.

What to checkHow to measure / readCompare with 225 data
Pole count / rated speedrpm on the old motor nameplate~2965 rpm → 2-pole (55×110); ~1485 or ~980 rpm → 4/6-pole (60×140)
Shaft diameter and lengthCaliper on the shaft, length from shoulder to end55×110 mm or 60×140 mm
Key widthWidth of the keyway16 mm (2-pole) / 18 mm (4/6-pole)
Foot holes (B3)Hole centre distances, across and lengthwiseA 356 mm; B 286 mm (225S) / 311 mm (225M)
Shaft heightFrom foot base to shaft axisH 225 mm
B5 flangeOuter diameter, spigot, bolt circle, hole sizeP 450 / N 350 / M 400 / S 18.5 mm

If the nameplate is unreadable, the shaft diameter alone is a strong clue: on the 225 frame, a 55 mm shaft appears in DRG data only on the 2-pole model. Ordering steps based on shaft and frame size are collected in the motor frame size order guide, and the price list by frame number lists models frame by frame.

Frequently asked questions

Is there a 45 kW motor in the 225S frame?

Not in DRG data. 225S carries only the 37 kW 4-pole DRG-225S-4. 45 kW is on the 225M frame in both 2-pole and 4-pole form.

Do the 45 kW 2-pole and 45 kW 4-pole motors have the same shaft?

No. Both are 225M, but the 2-pole shaft is 55×110 mm and the 4-pole shaft 60×140 mm; the key width also differs, 16 mm versus 18 mm.

Can a 225M motor replace a 225S motor?

Shaft height (225 mm) and transverse foot spacing (356 mm) are the same, but lengthwise foot spacing rises from 286 mm to 311 mm and the motor is longer. On 4-pole the shaft stays the same (60×140 mm); base holes and machine clearance must be checked separately.

Does the flange of a B5 225M motor change with pole count?

In DRG catalogue rows, P 450, N 350, M 400 and S 18.5 mm are identical in both 225M rows. What changes is the shaft (55×110 / 60×140 mm), the G value and the overall length.

Technical confirmation and ordering

DRG Motor is an electric motor manufacturer, supplier and seller. The fastest way to the right 225 frame model is to send us a photo of the existing nameplate plus the shaft diameter, shaft length, B dimension or flange dimensions. For the general features of large cast iron frames see cast iron frame and high kW motors and the DRG technical and product catalogue.

Send a photo of your current motor nameplate and we will find the suitable DRG model together.Send on WhatsApp

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Electric Motors Related to This Topic — Models and Current Prices

Suitability is not decided by power alone: compare the speed, voltage, mounting, shaft and fixing dimensions of your machine with the product data; if unsure, send us the nameplate of your current motor.

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