The fan was on-spec — the fitting wasn’t

The Setup

Picture a coating and finishing line where hot air has to move through a drying tunnel to cure the product. If the dryer blower stops, the line stops. Our customer — a surface-finishing and industrial-coatings manufacturer in Maharashtra — runs two identical Jitamitra hot-air blowers on exactly such a line at their end-user's plant. We'll call them the Coatings Maker. These are our fans, supplied by us, and that means when a service call comes in, it is ours to answer — and ours to diagnose honestly, wherever the cause turns out to sit.

The Complication

Two service calls landed on the same fan, months apart.

• First, the Coatings Maker reported high running noise traced to the blower's drive-end bearing — enough that work on the line was being held up until it was sorted.
• Later, on one of the two blowers, their engineers spotted something that looked more serious: a crack in the heat-resisting wheel (the "heat-slinger" plate) near the bearing housing, together with an abnormal sound. On a hot-air blower the heat-slinger throws heat off the shaft to protect the drive-end bearing, so a cracked one is a reliability flag — and they raised it as top priority.

A cracked component on a running fan is the kind of thing a buyer immediately reads as "manufacturing defect." The useful part of this story is what the diagnosis actually found.

The Diagnosis & Fix

Start with the finding, because it is the point of the case: the fan itself was on-spec. Our signed field record put down "Fan Manufacturing Defect = No." The crack did not begin in anything we fabricated. It traced to a bought-out heat component — the heat-slinger plate — and to its fixing bolt not being seated correctly. The earlier bearing call was normal wear: a bearing that had run its service life and needed changing, not a fault in the fan.

We didn't reach that by guessing. We tried remote diagnosis first — asking for photos and video — and when that wasn't enough to be sure, we sent an engineer to site rather than assume. On site, our engineer confirmed the failed heat-slinger, replaced the damaged plate with a new one and refitted it correctly with a new fixing bolt, properly seated, re-greased the bearing, and ran the blower under observation before signing off. On the earlier bearing call, we dispatched a full replacement bearing set with the correct adaptor sleeves and grease, changed the bearing, and re-issued the operating & maintenance manual and spare-parts list so the customer's team could maintain both blowers with confidence.

The reusable, engineer-to-engineer lesson — teach it, don't blame anyone: - A heat-slinger is a bought-out heat component that is fitted as a serviceable part. Its fixing has to be seated correctly at fitment; a fixing that isn't properly home lets the plate work loose and crack near the bearing housing. Treat the heat-slinger fixing as a checked, correctly-seated joint — at build and after any part change. - Bearings are scheduled wear parts. They are meant to be greased on a regular interval and changed on condition — a noisy bearing after a normal run is maintenance, not a defect. A simple greasing regime and the spares list keep both blowers running.

Because the failed heat component was bought-out, we didn't just swap it and move on. We debited it back to its supplier, and we tightened our own rule so any complaint involving a bought-out item (bearing, heat-slinger and the like) now routes straight to our purchasing team with supplier feedback captured. That is how a one-off field fix becomes a permanent process improvement.

(No fan-selection software, spec sheet, or internal codes are shown here; the customer's process detail is withheld.)

How We Made It Right

• The fan was proven on-spec. The field record recorded no fan manufacturing defect. The cause sat in a bought-out heat component and its fixing, and — separately — in a bearing that had reached the end of normal service life.
• Handled under warranty. Every Jitamitra fan carries our standard warranty — Jitamitra Electro Engineering · Technical Services Both service calls on this fan were accepted and resolved under warranty.
• We answered both, fast. We didn't argue the cause — we went to site, diagnosed it, and made the hardware right.
• Replaced free. Both the heat-slinger plate (with a new, correctly seated fixing) and the bearing set were supplied and fitted at no cost to the customer.
• Cause pushed back to source. The bought-out heat component was debited back to its supplier, the replacement was fitted correctly and run under observation, and the bearing was put on a regular greasing regime.
• So it routes faster next time. We made a standing process change: complaints involving bought-out components now go straight to purchasing with supplier feedback on record.

The Result

• Acknowledged the same day on both calls, within our commitment to respond to a service request within 4 working hours.
• On the heat-slinger crack, our engineer was on site the next day, the plate was replaced and the resolution signed off in about two days, and a formal technical-closure followed shortly after.
• The customer's site team marked the resolution satisfactory and co-signed the closure record on both calls.
• The relationship continued across both warranty touches on the same line — the real proof that diagnosing a cause straight, rather than defaulting to "no fault found," keeps a customer.

(No before/after vibration, noise or downtime figures are published — they were not measured in the record, and we don't invent numbers.)

The Takeaway + Call to Action

When a part on a running fan fails, the easy answers are "it's a manufacturing defect" or "it's not our problem." The useful supplier does neither — they go to site, find the real cause (here: a bought-out heat component, its fixing, and a bearing at end of normal life — with the fan itself on-spec), replace the parts free under warranty, push the cause back to source, and set the maintenance right. Want a fan backed by a supplier who diagnoses the real cause and owns the fix? Talk to us.

— Jitamitra Electro Engineering · Technical Services

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