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How to decide between rewinding and replacing electric motors in HVAC systems.


Electric motors drive the pumps, fans, and compressors that power Pretoria’s HVAC systems. When they fail, the question arises — rewind or replace? The right choice affects cost, downtime, and energy efficiency. This guide explains how ACCM Airconditioning’s in-house workshop helps Pretoria businesses make the right decision for every situation.

 

The Role of Motors in HVAC Systems

 

Every HVAC system relies on electric motors — whether they’re running fans, circulating chilled water, or powering compressors. These motors often operate for thousands of hours a year, exposed to heat, dust, vibration, and load stress common in Pretoria’s industrial environments.

 

Over time, insulation breaks down, bearings wear out, or windings short-circuit. When that happens, facility managers must weigh whether a motor rewind or full replacement offers the best long-term performance and value.

 

What Is a Motor Rewind?
 

Motor rewinding involves removing old copper windings from the stator and replacing them with new, insulated wire according to the original design.

 

A professional rewind restores the motor’s electrical and mechanical performance — extending its service life without altering speed, torque, or efficiency, provided it’s done to specification.

 

For motors up to 250 kW, a rewind is often faster and more affordable than importing or waiting for a replacement motor.

 

When Rewinding Makes Sense
 

Rewinding is a smart choice when:

 

  • The motor frame and rotor are in good condition
     
  • The replacement lead-time is long or costly
     
  • The damage is limited to insulation or shorted coils
     
  • The motor is part of custom or specialised equipment
     
  • The efficiency loss after rewind is minimal (≤1–2%)
     

Rewinding also supports sustainability — by reusing the housing and core materials, you reduce waste and the carbon footprint associated with manufacturing a new unit.

 

When Replacement Is the Better Option
 

Replacement is the right call when:

 

  • The stator or rotor is severely damaged
     
  • The motor has overheated beyond repair
     
  • Spare parts or technical data are unavailable
     
  • Upgrading to a high-efficiency or Variable Speed Drive (VSD)-compatible model improves performance
     
  • The motor is obsolete, inefficient, or high-vibration
     

A modern, high-efficiency motor can deliver lower operating costs and better ROI, especially in energy-intensive HVAC systems.

 

Cost and Downtime Considerations
 

In Pretoria, rewinding typically costs 40–60% of a new motor, depending on size and fault severity. But total impact extends beyond cost:

 

  • Lead-time: New motors may take weeks to source.
     
  • Compatibility: Mountings, couplers, and drives must align.
     
  • Downtime: A fast rewind can restore operation within days, minimising production loss.
     

The best decision balances cost, reliability, and efficiency, ensuring minimal disruption to operations.

 

How to Evaluate a Failed Motor
 

Professional workshops assess multiple factors before recommending a solution:

 

  • Winding insulation resistance (megger test)
     
  • Bearing and shaft alignment
     
  • Stator and rotor core condition
     
  • Vibration and temperature trends
     
  • Compatibility with Variable Speed Drives (VSDs)
     

This data-driven approach determines whether rewinding or replacement provides the best technical and financial outcome.

 

Benefits of Partnering with a Local Pretoria Workshop
 

✅ Faster turnaround: No waiting for imported parts.
✅ Controlled quality: Every step inspected locally.
✅ On-site pickup and delivery.
✅ Integrated expertise: Pumps, motors, and VSD systems serviced together.
✅ Local knowledge: Technicians familiar with Pretoria’s HVAC conditions.

 

Working with a local specialist like ACCM ensures minimal downtime and maximum return on your maintenance investment.

 

Why Choose ACCM Airconditioning (Pretoria.)
 

ACCM Airconditioning operates a full in-house workshop capable of rewinding electric motors up to 250 kW (3-phase).

The team also performs mechanical repairs on pumps, supplies Variable Speed Drives (VSDs) and new motors, and conducts on-site performance inspections to detect inefficiencies before failure.

 

This integrated service model—combining electrical, mechanical, and preventative expertise—makes ACCM one of Pretoria’s only HVAC providers capable of managing both rewinds and replacements under one roof.

 

“Our Pretoria workshop helps clients save thousands by restoring critical motors quickly and correctly. Rewind or replace, we guide each decision based on data and long-term value.”
— ACCM Airconditioning Workshop Team