Commissioning Report Drum Heating Oven And Motor Drying Oven Line Two

By Author: MV International
Total Articles: 2
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First Power-Up After Installation

Line two was finally ready for commissioning after the civil work and ducting delays pushed us back almost three weeks. Before energizing anything, I went through the full electrical schedule with the installation crew, checking torque on every busbar connection in the main panel and confirming the earthing continuity across both chamber bodies with a low resistance ohmmeter. One earthing strap on the Drum Heating Oven frame showed a reading slightly higher than the rest, traced it to a paint-coated bolt where the crew hadn't scraped the surface properly before fitting the lug. Cleaned the contact point and re-torqued it before allowing first power-up.

Dry Run Without Load On The Drum Heating Oven

Ran the chamber empty for two hours to check heat-up behavior before putting any product inside. Chamber climbed to 130°C in about eighteen minutes, which was faster than expected for a unit this size, so I pulled the heater bank wiring diagram again just to confirm the elements were wired in the correct configuration ...
... rather than accidentally paralleled instead of series-parallel as specified. Wiring checked out fine, the fast climb was simply because the chamber was still new and hadn't picked up any thermal mass losses yet from product or moisture. Recorded the empty-chamber heat-up curve for future reference since this baseline helps later when troubleshooting slow heating complaints.

Checking Fan Rotation And Static Pressure

Verified the recirculation fan was rotating in the correct direction, since reversed fan rotation on a new install is more common than people expect, especially when the site electrician wires the motor without checking rotation against the fan housing arrow. Fan was correct here, but static pressure across the duct work measured lower than the commissioning sheet specified, about 15 percent under target. Found a damper that had been left in a half-closed transport position from the factory, adjusted it fully open, and pressure came back within range.

Loading Flux Drums For The First Production Trial

For the trial run, loaded flux material drums that needed moisture removal before they could go into storage. Kept a gap between each drum row rather than stacking them tight against each other, since this was the first real load and I wanted to see actual airflow behavior rather than assume it from the empty chamber test. Surface temperature across the drums varied by about four degrees between the front row and back row closest to the return air duct, acceptable for a first trial but something to monitor as more batches run through.

Motor Drying Oven Trial With Varnish Coated Stators

On the Motor Drying Oven side, the trial load was a set of stators that had just come through the varnish dip tank before final bake. Varnish baking needs a controlled ramp because if the surface skins over too fast, solvent trapped underneath can blister the coating instead of curing clean. Set the ramp at 2°C per minute up to 150°C and watched the chamber closely through the first forty minutes since this was an unfamiliar load type for this particular oven.

Solvent Vapor Behavior During Early Ramp

Around the twenty minute mark, noticed condensation forming on the inside of the observation window, which is normal for varnish baking as solvent vapor releases and hits the cooler glass surface before the chamber fully warms through. What wasn't normal was a faint haze building up near the exhaust vent opening, which pointed to the exhaust damper not pulling enough vapor out of the chamber. Opened the exhaust damper further and the haze cleared within about ten minutes, confirming it was an airflow issue rather than a heater or control fault.

Conveyor Line Speed Calibration

The third piece of equipment on this line was a conveyor-based continuous heating unit meant for composite curing on smaller parts. Belt speed had been pre-set by the factory but needed calibration against the actual dwell time this cure cycle required. Ran timed pieces through the chamber at three different speed settings and checked core temperature of the composite samples using an embedded probe rather than relying on the surface reading alone, since composite parts often show a lag between surface and core temperature during cure. Settled on a belt speed that gave a fourteen minute dwell time, slightly longer than the factory default, since the shorter dwell wasn't letting core temperature catch up to the target cure profile.

Control Panel Sensor Cross Check

Before signing off the commissioning, cross-checked every chamber thermocouple against a calibrated reference probe, one station at a time. Drum Heating Oven chamber sensor read within half a degree of the reference, acceptable. Motor Drying Oven chamber sensor read almost two degrees low, outside the tolerance the commissioning checklist called for. Rather than adjust the offset in the controller software straightaway, flagged it for the instrumentation team to physically re-verify the thermocouple grade and connection before making any calibration change, since a wiring or connection issue can mimic a sensor drift and adjusting software over it just hides the real fault.

Final Documentation Before Handover

Went through the full commissioning checklist one more time with the site supervisor, noting the earthing bolt correction, the damper adjustment on the drum line, the exhaust damper correction on the motor drying side, the conveyor speed setting for the composite cure cycle, and the sensor discrepancy flagged for instrumentation. Walked both chambers with the electrical contractor present so nothing would be disputed later about what condition the equipment was handed over in. Checked each temperature controller one final time to confirm they had settled back to standby, switched off the main power from the panel, closed both oven doors properly, and left the site once the handover paperwork was signed for the day.