Winders work to a daily count: HR for electric motor manufacturers

A chalk board beside the winding tables shows each winder's stators for the day. The highest number earns a word of praise from the supervisor and, at month end, the biggest incentive. Three months after the summer rush, a pump maker sends back a crate of burnt monoblock motors. Stripping them shows nicked enamel where wire left the slot, a missing phase separator and coils that had shifted in the overhang.

Nobody on the floor did anything strange. They did what the board asked. That is the first pressure point on an electric motor line: the daily count, set up to reward output, quietly pays for speed in the one place speed does the most harm.

• Slot liners pushed in crooked so a corner of the slot cell folds, leaving copper close to the core.
• Coils forced in with a drift rather than fed, scraping enamel on the slot edge.
• Phase paper skipped or cut short between phases in the end-turn, because fitting it costs a minute.
• Wedges driven before the slot is settled, trapping a strand across the opening.
• Lacing done loosely, so end-turns move under vibration and rub against each other.
• Lead sleeving left short at the connection, inviting a fault where leads cross.

A rushed stator usually passes the bench. Resistance is balanced, the no-load run sounds fine and the motor ships. The weakness is in insulation that is thinner than it should be. Heat from long running, moisture in a borewell and vibration from a pump wear that spot down. Weeks or months later an inter-turn short or an earth fault burns the winding. By then the batch has left, the season is over and nobody knows which table it came from.

• Warranty replacements and the stripping time to find out what failed.
• A pump or fan customer who starts inspecting every lot, or quietly adds a second supplier.
• Careful winders earning less than fast ones, and either leaving or learning to rush.
• Seniors spending evenings rewinding returns instead of training the next batch of hands.

Owners keep the count for good reasons. It is simple, everyone understands it, and it links pay to output. Counting is not the mistake. Counting the wrong thing is.

1. 1

   Count only stators that clear the first bench run

   A stator scores when its motor passes resistance, surge comparison and the no-load run first time. A motor that needed a rewind scores nothing for anyone.

2. 2

   Stamp each stator with the winder's code

   A punched or painted code on the stack or the route card, so a return from the field leads to one table for coaching.

3. 3

   Post a weekly board, not a daily race

   For each winder: stators passed, first-run fails and returns traced. Read it on Friday, with the senior winder present.

4. 4

   Make the senior a coach

   When a fail traces to a winder, the senior strips it beside them and shows the fault. Nobody is named on the shop notice board.

5. 5

   Hold seasonal hands on lacing and leads

   New hires before the pump season start on lacing, sleeving and shaft work, and move to full winding only after a signed sample stator.

6. 6

   Rebuild the incentive around passes

   If an incentive exists, base it on passed stators and returns, with expert advice on how the change is introduced.

The measures are set out on the motor line performance page. Pay grades for winders, balancers and bench testers are on the motor works pay benchmarking page.

WEEK: ______  WINDER CODE: ______  TABLE: ______  GRADE: ______.
FRAME SIZES WOUND: ______.
STATORS PASSED FIRST BENCH RUN: ______.
FIRST-RUN FAILS, WITH CAUSE: slot liner / enamel nick / phase paper / lacing / leads / other.
FIELD RETURNS TRACED TO THIS CODE: ______, with the cause found on stripping.
COACHING GIVEN BY SENIOR: ______ (what was shown, on which stator).
WINDER'S OWN NOTE: anything slowing the work, such as wire quality or blunt tools.

• Count last week's first bench-run fails and sort them by winder, even by hand.
• Open the motors returned since the last season and see how many carry any winder's mark.
• Ask your senior winder which slot or end-turn faults he corrects most often in others' stators.
• Look at how the incentive is calculated today and whether a failed motor still counts.
• Walk to the varnish tank and check the extraction fan and masks while orders are heavy.

Fume and oven routines that hold up in a heavy week are on the motor works health and safety page. The electric motor manufacturers page covers the line's other strains, and the hub for electrical equipment makers compares them with transformer and panel work.