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Pressurization Fan Motor Bearing Replacement | Mechanical Restoration by EKG

In a high-rise fire emergency, a Pressurization Fan must ramp from zero to full speed in seconds. This sudden torque is brutal on motor bearings, especially if the fan has been sitting idle in KL’s humidity. When bearings begin to "growl" or vibrate, it isn't just a noise issue—it’s a ticking clock until the motor seizes, potentially leading to a failed BOMBA inspection or, worse, a compromised escape route.

As part of a Ventilation Systems Audit, EKG provides precision Motor Bearing Replacement to restore your life-safety fans to "Factory-Quiet" reliability.

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1. The "Idle-Death" of Fire Fan Bearings

Unlike a standard AC fan that runs 24/7, pressurization fans suffer from False Brinelling.

• The Cause: Constant building vibrations (from elevators or nearby traffic) press the bearing rollers into the race while the fan is stationary.

• The Result: Tiny "micropits" form. When the motor finally starts during a fire test, these pits cause rapid heat buildup and metal fatigue.

• The Warning Sign: If your fan sounds like a "grinding mill" or shows vibration levels above 2.8 mm/s, the bearings have already structurally failed.

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2. The EKG "Zero-Tolerance" Replacement Protocol

We don't just "hammer in" new bearings. We use precision mechanical engineering to ensure a 10-year lifespan:

• Induction Heating Installation: We never use hammers, which can damage new bearing races. We use Induction Heaters to expand the bearing inner ring, allowing it to slide onto the shaft perfectly before shrinking into a "tight-fit" lock.

• High-Temp Synthetic Greasing: We use specialized lubricants rated for high-speed emergency starts. Standard grease can "channel" or dry out in a motor that sits idle for 30 days between tests.

• Shaft & Housing Tolerance Audit: We use digital micrometers to check for "Shaft Runout." If the shaft is worn down even by 0.01mm, the new bearing will spin on the shaft, causing total motor failure within months.

• Laser-Guided Re-Alignment: After the motor is reassembled, we use Laser Alignment to ensure the motor pulley and fan pulley are perfectly parallel.

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3. The Energy & Mechanical Impact: The Cube Law

A motor with "draggy," worn bearings is an energy thief. It draws significantly more Amperage ($A$) just to overcome its own internal friction.

• Friction Elimination: New, high-grade bearings reduce the "Starting Torque" required.

• The Logic: Because of the Cube Law, a motor that is mechanically "slick" can hit its required pressure target (e.g., 50 Pa) at a lower frequency (Hz).

Replacing worn bearings often allows us to tune the Variable Frequency Drive (VFD) to run at a lower speed, reducing power consumption by up to 20% during mandatory monthly tests.

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4. Bearing Health & Replacement Matrix

Symptom	Mechanical Condition	EKG Action Required
High-Pitched Whine	Lack of Lubrication / Retainer Wear	Flush & Re-grease or Replace
Low-Frequency Rumble	Race Pitting (False Brinelling)	Immediate Bearing Replacement
Hot Motor Housing	Excessive Friction / Over-greasing	Infrared Audit & Bearing Reset
Vibration > 4.5 mm/s	Impending Seizure / Shaft Damage	Emergency Overhaul & Balancing
Visible "Metal Dust"	Total Bearing Disintegration	Full Motor Teardown & Shaft Repair

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5. Why Trust EKG for Bearing Replacements?

• BOMBA Compliance: We provide the "Before & After" vibration reports required to prove your fan is fit for its annual Fire Certificate (FC) renewal.

• On-Site Service: For large fans, we perform the replacement in your mechanical room to avoid expensive crane costs and building downtime.

• VFD ROI Projection: We calculate the exact energy savings achieved by restoring your motor’s mechanical efficiency.

• Precision Parts: We only use premium, high-load bearings (SKF, FAG, or NSK) specifically rated for vertical or high-torque applications.