Prediction Report

Ticket #JOB-2 · July 9, 2026 · Predicted

Submitted inputs · July 9, 2026 · 5:27 PM

Nameplate

hp: 75

rpm: 1180

frame: 365T

voltage: 460

phase: 3

Symptoms

Does it run at all?: trips on start

Drive & installation

Environment: washdown wet

Shop queue: 2 days

Tests

Insulation resistance: 2.0 MΩ @ 500.0 V

Polarization index: 1.1

Surge: fail

Winding resistance: [0.4, 0.41, 0.4]

Ground/continuity: fail

Notes

sat outside through winter, trips on start, rust on conduit box

◐ Two-stage bindConfidence 87/100 · High

Executive summary

Multiple hard-failure signals converge on a ground-wall/turn insulation breakdown: fails ground continuity, fails surge, low PI (1.1) with marginal insulation resistance, and trips on start after a wet winter. Keep locked out — do not attempt to run. Confirm and localize with insulation and surge testing; this motor is almost certainly headed for rewind.

Est. cost · internal

$5,200

Labor

49 hrs

Turnaround

11 business days

Repair vs. replace

Repair if cost < ~60% of a new motor; otherwise replace

Likely failure mode

Highground-wall insulation failure to frame

Mediumturn-to-turn / phase winding short

Lowmoisture/contamination surface tracking (recoverable)

Required repairs

• Rewind stator (pending teardown/test confirmation)
• Clean, dip and bake windings if drying reveals recoverable moisture only (pending confirmation)
• Clean/re-terminate and seal conduit box; address moisture ingress path

Material staging

Magnet wire (copper, rewind) ×lot · ~4d lead

98% likelyorder before teardown

Insulation kit — slot liners, wedges, phase paper ×1 set · ~3d lead

98% likelyorder before teardown

DE bearing ×1 · ~2d lead

95% likelyorder before teardown

ODE bearing ×1 · ~2d lead

95% likelyorder before teardown

Shaft / bearing seals ×set · ~1d lead

95% likelycheck stock

Varnish / resin (VPI or dip-and-bake) ×as req

95% likelycheck stock

Lead wire & sleeving ×as req · ~1d lead

80% likelycheck stock

Labor — 49 hrs total

Teardown & clean

7.3 h

Strip & rewind

22.1 h

Fit new bearings

3.9 h

VPI / dip & bake

5.9 h

Reassemble

5.9 h

Test & balance

3.9 h

Reinstall & coverage

• Reinstall & laser alignment on site — field service, quoted separately
• 12-month workmanship warranty — carried in the estimate
• Preventive maintenance plan — optional add-on

Sharpen estimate

Add evidence to tighten the estimate and raise confidence:

• Photo of the winding (burn pattern) — burn pattern often fixes the mode and the rewind extent

• IR/PI after controlled oven-dry (recovers or not) — reduces remaining uncertainty in the scope

• Which phase the ground fault localizes to — reduces remaining uncertainty in the scope

Confirmed outcome

Reasoning

ground-wall insulation failure to frame — tests: ground/continuity fail; tests: PI 1.1 (poor, non-recovering)

turn-to-turn / phase winding short — tests: surge test fail; physics: 2% winding-resistance imbalance flags asymmetry

moisture/contamination surface tracking (recoverable) — free text: sat outside through winter, washdown/wet, rust on conduit box

poor connection at conduit box (rust/corrosion) — free text: rust on conduit box; physics: winding-resistance imbalance

No confirmation of whether insulation recovers after drying; without a post-dry IR/PI the split between hard ground-wall failure and recoverable moisture cannot be fully settled, capping overall confidence.