⚡ Preventative Maintenance Audit: Clover DC – Queensburgh

Client: Clover South Africa
Site: Distribution Centre, Queensburgh
Scope: Preventative Electrical Maintenance, Thermal Scanning, Load Verification
Focus: Ammonia Refrigeration System, Compressor Room, MCC & Condensers
Date: March–April 2025

---

Project Overview

Clover's Queensburgh DC operates a high-load ammonia-based refrigeration system integral to its cold chain logistics. Our team conducted a preventative maintenance inspection across the facility’s electrical infrastructure — covering compressors, condensers, MCC busbars, and signal/control terminations.

Given the safety-critical nature of ammonia systems and the high uptime required by the client, the goal was to identify potential electrical failures before they occur — especially those that can lead to equipment damage, energy loss, or fire risk.

---

Audit Objectives

• Conduct thermal scans of VSD panels and MCCs
• Measure compressor current draw
• Inspect terminal integrity, busbar condition, and connection tightness
• Identify hotspots, scorched components, and degraded insulation
• Generate a report with actionable rectification steps

---

Key Findings

🛑 Critical Thermal Hotspots Identified

• Issue: Panels for Condensers 3, 4, and 5 were found operating above 120°C, with the highest recorded at 126°C (limit: 65°C).
• Cause: Potential overloads, undersized breakers, or poor terminal torque.
• Action: Replace overloads and re-terminate all cables with proper torque checks.

---

🔥 Scorched Panels & Component Burnout

• Issue: Visual burn marks inside Condenser 5 control panel.
• Cause: Loose terminal creating arc fault or short from overcurrent.
• Action: Replace terminals, strip and rewire affected cores, check upstream protection.

---

📉 Compressor Load Discrepancies

• Issue: Load monitoring on High Stage Compressors showed unbalanced amp draw, with one unit barely pulling current.
• Action: Test compressor contactors, verify signal from control logic, and inspect VFD state.

---

⚠️ Busbar & CT Section: Dust, Heat, and Oxidation

• Issue: Early signs of terminal discoloration and possible oxidization under load.
• Action: Clean, apply anti-oxidant paste, re-tighten, and monitor under thermal scan after reloading.

---

🔎 Miscellaneous Observations

• Burnt terminal blocks in multiple panels (Condenser 3 & 5).
• Damaged earth bonding and conduit fittings requiring securement.
• Loose ferrules and unlabeled cores in one section of signal termination.
• Low stage accumulator sensor plate showed corrosion and high surface heat due to poor contact.

---

Results & Recommendations

The preventative inspection revealed several high-risk faults which, if left unattended, could have led to equipment failure, downtime, or panel fires. All faults were logged and submitted to the client for rectification, with priority listed by severity.

Top 3 Recommendations:

1. Replace all damaged terminals and overloads in Condenser panels 3–5.
2. Retorque and clean all MCC and CT busbar connections.
3. Update panel protection and introduce scheduled thermographic scans every 6 months.

---

Why Preventative Maintenance Matters

In critical infrastructure like cold storage and ammonia plants, preventative maintenance isn’t optional — it’s your insurance against breakdowns and risk. Proactive inspections allow us to catch thermal stress, wiring fatigue, and load irregularities before they cause downtime or damage.