Wrong rotation, bad foundation, rigid ducts

Wrong rotation, bad foundation, rigid ducts. Those three account for almost every commissioning failure we are ever called out to. Not exotic ones — those three.

A fan running backwards still moves some air, so it looks like it is working while it delivers a fraction of its rated flow and draws high current. A base bolted onto green concrete cracks under vibration. Ducting bolted rigidly to the fan flanges puts its own weight and its own movement through a casing that was never built to carry either.

All three are caught in the ten minutes before start-up, by someone who knows to look. That is what our field card is for: JEE-SVC-008 — four pages, belt, coupled and direct drive, written for site rather than for a specification file. From 1 September 2026 a copy travels with every blower we dispatch. Keep it with the fan.

Before anyone presses start — tick all ten

This is the part worth reading on your phone while standing at the machine.

• GA drawing on site and read
• Anti-brinelling device removed
• Bearings freshly greased, if stored over 45 days
• Shaft turns freely by hand
• Impeller clear of casing and inlet cone
• Yellow bellow transport brackets removed
• All foundation bolts torqued, fan level
• Belt guard or coupling guard fitted
• Nothing loose inside the casing or ducting
• Phase sequence checked with a meter

Then bump the motor and watch which way the impeller coasts down — it must match the arrow on the casing. That single check is the commonest commissioning fault there is.

Once it is running — the numbers that decide whether to stop the fan

Vibration limits are ISO 14694:2003 Table 5, in situ, category BV-3, rigidly mounted. On anti-vibration mounts or springs: alarm 11.8, shutdown 12.5 mm/s r.m.s. These apply after the first 24 hours — on the very first run a bearing at 100–115 °C between thirty minutes and two hours is normal, fresh grease churning before it settles. The card draws that curve so nobody shuts down a healthy new fan, and tells you when it stops being normal.

Fill in the commissioning record, and send us a photograph

Page 3 has a record to complete at handover: bearing temperatures, vibration at both bearings, current on all three phases, belt deflection, and who commissioned it. Photograph it and send it to us, and we file it against your J-number.

That is not paperwork for its own sake. It means that the day you call us about a fan, we already have the numbers it started life with — and a fan that has moved from 1.8 to 3.5 mm/s is telling you something real, even while it is still well inside the limit. Without a baseline, that same reading says nothing at all.

When you need more than four pages

Our troubleshooting guides are written by our service engineers from ten years of field work, on fans and blowers of any make: symptom, how to diagnose it, the usual root causes, the fix, and how to stop it coming back. There are fifteen of them. They are free, they need no form, and they do not care whose badge is on your fan. The QR code on page 4 of the card opens them directly.

• All fifteen troubleshooting guides →
• Commissioning & installation errors
• High vibration after commissioning
• Bearing running hot or noisy
• Damage found on arrival
• Fan not making its duty
• Belt drives: slip, smoke, misalignment
• Fan & blower glossary

The full manual is JEE-MAN-001 and governs in every case — ask and we will send it. If something on site is not covered by the card, tell us: this is Rev 01, and what you hit goes into Rev 02.

Jitamitra Electro Engineering · Published 17 August 2026. News and updates from the works at MIDC Ahilyanagar.