When renewing a 1.5 kW WAT electric motor, the most common problem is not power but dimensions: the new motor does not sit on the base, the coupling hub does not fit the shaft, or the pulley alignment shifts. This article shows which frame and shaft sizes exist for 1.5 kW WAT motors, how to measure them, and which figures to compare with DRG MOTOR models.

Which frames carry 1.5 kW in the WAT catalogue?

According to the IE3 dimension tables in the WAT IM tr 24.0 catalogue, 1.5 kW motors come in these frames:

  • 2-pole (3000 rpm class) standard: Q3H90L2C – frame 90, shaft 24×50 mm, aluminium; the cast-iron Q3HG90L2C has the same frame and shaft
  • 2-pole HS type: Q3HS90S2C – frame 90, shaft 24×50 mm
  • 2-pole compact: Q3H80M2DE – frame 80, shaft 19×40 mm
  • 4-pole (1500 rpm class): Q3H90L4D and cast-iron Q3HG90L4D – frame 90, shaft 24×50 mm

The conclusion is clear: "1.5 kW 2-pole" alone may point to either frame 90 or frame 80. In the compact type the shaft is 19 mm instead of 24 mm in diameter and 40 mm instead of 50 mm long, which directly affects the coupling and pulley hub. The same kW and speed class do not mean the dimensions will match.

Grey three-phase electric motor with DRG MOTOR logo – frame and shaft dimensions for replacing a WAT 1.5 kW motor

The S and L letter in the frame designation

In the WAT type code, the letter after the frame size (S short, M medium, L long) describes the frame length. At the same 90 shaft height, S and L frames have different longitudinal foot-hole spacing in IEC dimensions. In the DRG MOTOR range, for example, this spacing (B) is 100 mm on frame 90S and 125 mm on frame 90L. If your current motor's code says 90L and the base holes are 125 mm apart, a 90S motor may need extra holes in the base. Measuring the base is the way to be sure.

What to measure on site

Even if the nameplate is readable, taking these measurements with a rule and calliper reduces later surprises:

  • H: height from the base to the shaft centre (90 mm on frame 90)
  • A: transverse foot-hole spacing; B: longitudinal spacing
  • Foot-hole diameter (K)
  • D×E: shaft diameter and shaft extension length; F: key width
  • L: overall motor length (to fit inside the machine body or guard)
  • If flanged: flange outer diameter, bolt circle and spigot diameter

Dimensions of DRG MOTOR 1.5 kW models

DRG Motor is an electric motor manufacturer, supplier and seller. Dimensions of the 1.5 kW models in the aluminium housing motors group are below (mm):

ModelFrame / HA × B / KShaft D×E / F
DRG-90S-2 (2-pole, 2895 rpm)90S / 90140 × 100 / 4–Φ1024×50 / 8
DRG-90L-4 (4-pole, 1445 rpm)90L / 90140 × 125 / 4–Φ1024×50 / 8
DRG-100L-6 (6-pole, 949 rpm)100L / 100160 × 140 / 4–Φ1228×60 / 8

Overall length (L) is 336 mm for DRG-90S-2, 361 mm for DRG-90L-4 and 406 mm for DRG-100L-6. For B5 flange mounting, frame 90 flange dimensions are P 200, M 165, N 130 mm. If your current motor is the compact type with a 19×40 mm shaft, whether an option matching that shaft size exists must be checked separately; if a move to a 24×50 mm shaft is considered, its effect on the coupling and base should be assessed by competent technical staff.

Send your measured values and a nameplate photo to DRG MOTOR so the suitable model can be determined against the table values. For detailed dimension drawings see the technical drawings page, and for the full range the DRG MOTOR electric motor shop.

Questions on 1.5 kW replacement

What if the shaft diameter is the same but the length differs?

The surface on which the coupling or pulley hub sits changes. A short shaft may not give enough grip, a long one may hit the guard; it must be assessed according to the machine layout.

Are cast-iron WAT electric motor dimensions different from aluminium?

In the WAT catalogue the 1.5 kW cast-iron types also have frame 90 and a 24×50 mm shaft. Details such as frame diameter, terminal box position and foot thickness may differ by material, so measure these too in tight spaces.

What if the nameplate shows no frame number?

The shaft centre height above the base largely indicates the frame number. Even so, the longitudinal foot-hole spacing should be measured to distinguish S from L.

Dimension list to send to DRG MOTOR

  • WAT nameplate photo and full type code (e.g. Q3H90L2C, Q3H80M2DE)
  • Number of poles or rated speed on the nameplate
  • H, A, B and foot-hole diameter
  • Shaft diameter × length and key width
  • Overall length and any points with fitting constraints
  • Flange dimensions if flanged; whether a coupling or pulley is used
  • Machine type and operating environment

When you send the dimensions via WhatsApp (+90 542 666 11 11), the quote list, by phone or to info@drgmotor.com, the assessment is made with these data. Other channels are on the contact page.

See current prices of DRG MOTOR electric motors and order online in our storeSEE PRICES →

Technical Sources

  • WAT Motor Sanayi ve Ticaret A.Ş. — WAT Product Catalogue (Turkish edition) — IM tr 24.0 — Motor type codes, PDF page 18 (printed page 16); IE3 three-phase aluminium motors, electrical data 50 Hz, PDF pages 38–39 (printed pages 36–37); IE3 three-phase aluminium motors, dimensions B3, PDF pages 44–45 (printed pages 42–43); IE3 three-phase cast-iron motors, electrical data 50 Hz, PDF page 76 (printed page 74); IE3 three-phase cast-iron motors, dimensions B3, PDF pages 77–78 (printed pages 75–76).