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Marathon X503 Replacement

The Marathon X503 is a 1-1/2 HP, 1140 RPM three-phase open-air-over (OAO) condenser fan / heat pump motor (56Y frame, belly-band mount). Below: the specs we verify before quoting, and what to check on your nameplate.

Verified specifications

Horsepower1-1/2 HP
Speed1140 RPM (6-pole)
Voltage200-230/460V (VCD voltage-change device)
PhaseThree-phase
Frequency60/50 Hz
Frame56Y
EnclosureOpen Air Over (OAO)
Full-load amps5.5-5.4/2.7 A
MountingRound belly band / resilient ring
Shaft5/8 in. dia. x 5 in. long, with flat and keyway
BearingsDouble-sealed ball bearings
RotationReversible
Thermal protectionAutomatic reset thermal protector
Max ambient70°C
Marathon model number056T11O5303
Weight35 lb (catalog)
CertificationsUL Recognized, CSA Certified

Open-air-over (OAO) motors are cooled by the fan's own airstream — the X503 must be mounted in the airstream to run at rated load.

Do not confuse with the X503-P (model 056T11O15570), a separate 56Z-frame variant — check the frame on your nameplate.

Confirming the right replacement

Before we quote, compare these fields on your failed motor's nameplate. If any of them differ, send us a photo of the nameplate and we'll match it exactly rather than guessing:

Other Marathon models

Need a Marathon X503?

Send the nameplate off your failed unit. We'll confirm the match and quote the X503 or a verified equivalent with availability and lead time.

Quote this motor