Leeson Motor Cross Reference: What the Part Number 056B17DR370036A1 Tells You
When you're sourcing a replacement electric motor — whether for an industrial application, an automotive shop compressor, a car lift, or another piece of shop equipment — part numbers like 056B17DR370036A1 aren't random strings. They're coded specifications. Understanding how Leeson motor part numbers work, and how to cross-reference them to equivalent motors, is practical knowledge for anyone maintaining power equipment in a repair or fleet environment.
What Leeson Motors Are and Why They Show Up in Auto Repair Contexts
Leeson Electric is a manufacturer of AC and DC electric motors widely used in commercial and industrial equipment. In automotive settings, Leeson motors commonly power:
- Vehicle lifts and hoists
- Air compressors
- Parts washers
- Lube and fluid transfer equipment
- Shop fans and ventilation systems
- Hydraulic power units
When one of these motors fails, the nameplate part number becomes your starting point for finding an exact replacement — or a cross-referenced equivalent from another manufacturer.
How to Read the Leeson Part Number 056B17DR370036A1
Leeson's catalog numbers are structured to encode the motor's physical and electrical specifications. Breaking down 056B17DR370036A1:
| Segment | What It Typically Indicates |
|---|---|
| 056 | Frame size (NEMA 56 frame) |
| B | Body or mounting configuration variant |
| 17 | Horsepower or output indicator within the series |
| DR | Design or enclosure type (e.g., DRIPPROOF) |
| 37 | Voltage or speed code |
| 0036 | Internal catalog sequence |
| A1 | Revision or feature suffix |
⚙️ Not every position maps identically across all Leeson product lines — the company has used multiple catalog numbering systems across different eras and motor families. Always verify against the motor nameplate data rather than relying on the part number alone.
What "Cross Reference" Actually Means for Electric Motors
A cross reference finds a motor from another manufacturer — such as Marathon, Baldor, WEG, Dayton, or Century — that matches the original motor's critical specifications closely enough to serve as a drop-in or functional replacement.
The specifications that must align for a valid cross reference include:
- Horsepower (HP)
- RPM (full-load speed)
- Voltage and phase (115V/230V single-phase or 208-230/460V three-phase)
- NEMA frame size (determines physical mounting dimensions)
- Enclosure type (TEFC, ODP, DRIP-PROOF, etc.)
- Service factor
- Rotation direction
- Shaft diameter and length
- Mounting configuration (face mount, base mount, C-face, etc.)
A part number cross reference alone is not a guarantee of compatibility. Two motors with matching frame sizes and horsepower can still differ in shaft length, conduit box position, or thermal protection type — details that matter in a tight installation.
How to Cross-Reference a Leeson Motor
Step 1: Pull the nameplate data directly. The motor's metal nameplate carries the authoritative specs: HP, RPM, voltage, frame, Hz, full-load amps, and service factor. The catalog number on the nameplate is your primary lookup tool.
Step 2: Use manufacturer cross-reference tools. Leeson (now part of Regal Rexnord) and competing manufacturers like Marathon Electric, Baldor (ABB), and WEG maintain cross-reference databases — available through their websites or through industrial distributors. Entering the Leeson catalog number typically returns a list of equivalent models.
Step 3: Verify physical dimensions independently. Even after a cross-reference match, compare the NEMA frame drawing for the replacement motor against the original. NEMA frame standards set shaft height and bolt patterns, but accessory details vary by manufacturer.
Step 4: Check application-specific requirements. Some equipment manufacturers void warranties or have performance concerns if non-OEM motors are installed. This is less common with commodity NEMA-frame motors but worth confirming for lift equipment or any safety-rated application.
Variables That Shape Your Replacement Options 🔍
The right cross reference depends on more than the part number:
- Age of equipment — Older Leeson catalog numbers may reference discontinued frames or designs, narrowing equivalent options
- Single-phase vs. three-phase power — Shop power availability directly limits which replacements are viable
- Application duty cycle — Continuous-duty vs. intermittent-duty ratings affect which motors are appropriate
- Enclosure requirements — A TEFC (Totally Enclosed Fan Cooled) motor matters in wash-down or dusty shop environments; ODP (Open Drip-Proof) does not seal out contaminants the same way
- Inverter compatibility — If the motor runs on a VFD (variable frequency drive), it needs to be rated for inverter duty
- Availability and lead times — Exact Leeson replacements may be stocked locally or require ordering; cross-referenced alternatives from stocked brands may be faster
The Gap Between the Part Number and Your Specific Motor
A cross-reference lookup gives you candidates — not a confirmed answer. The nameplate on the motor you're replacing, the physical constraints of the equipment it powers, and the power supply available in your shop are what actually determine which replacement works. Two shops with the same Leeson part number could end up with different viable options based on installation geometry alone.