ABB

M3BP Cast-Iron (Process Performance)

Rotary-screw and centrifugal compressors globally.

Nameplate

Phase: 3-Phase
HP range: 1 – 900 HP
Voltage codes: 230/460 V · 460 V · 575 V
NEMA frames: IEC 63 – 450 (NEMA 143T – 5011)
Enclosure: TEFC IP55 (IP56 optional)
Poles / RPM: 2, 4, 6, 8
Efficiency: IE3 / IE4
Insulation class: F (Class B rise)
Service factor: 1.15
Family: M3BP / M3AA

Lead connection diagrams

9-lead Wye (High voltage · 460 V)

L1 ─┬─ T1 ── T7
L2 ─┬─ T2 ── T8
L3 ─┬─ T3 ── T9
     T4 ─┐
     T5 ─┼── tied together (neutral point)
     T6 ─┘

Tie T4-T5-T6 together and insulate. Feed line to T1/T2/T3; jumper T7-T1, T8-T2, T9-T3.

9-lead Delta (Low voltage · 230 V)

L1 ─┬─ T1 ── T6 ── T7
L2 ─┬─ T2 ── T4 ── T8
L3 ─┬─ T3 ── T5 ── T9

Parallel pairs: T1-T6-T7, T2-T4-T8, T3-T5-T9. No neutral tie.

Schematics & manuals

ABB low-voltage motor manual (3GZF500730-85)

Links point to the manufacturer's own PDF hosting. If a link 404s, search the model number on the manufacturer's Download Center — filenames change with revision.

Field notes

6-lead terminal box standard on IEC frames — connect wye or delta by jumper bar orientation.
M3AA is aluminum frame (smaller HP); M3BP is cast iron for compressor duty.

The connection charts above are the NEMA MG-1 industry-standard patterns most brands follow. Always confirm the exact chart printed inside your motor's peckerhead lid before landing leads — voltage-code and lead-tag conventions vary between OEMs and production years.

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