4 Steps of Power Loggers & Cable Tray Sizing use in commercial solar systems

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How to clamp power logger at Main Switch Board (MSB)

Before designing a commercial solar system, we must understand the facility’s actual energy usage. The process begins by installing a power logger at the Main Switch Board (MSB) where the incoming power supply from Tenaga Nasional Berhad (TNB) enters the building.

Since the Main Switchboard (MSB) operates with high voltage level, the installation of current transformer (CT) sensors and the connection of voltage leads must be performed exclusively by a certified chargeman to ensure safety and compliance with electrical regulations. Once installed, our engineers will set up the power logger and verify correct phase readings on all channels.

In accordance with TNB’s standard procedure for solar applications, the logger records the energy usage data for a minimum of four days, covering two weekdays and two weekend days. Typically, the monitoring period is scheduled from Friday to Monday. This approach ensures a comprehensive representation of both daily operational loads and off-hour energy usage, providing a complete overview of overall energy consumption patterns.

How to Extract Data and How to Analyze Client’s Load Profile

After monitoring is completed, the raw data is extracted and processed into hourly kW usage for the full four days. The results are then filled into the official TNB Customer Load Profile Form, a compulsory document for every application.

This form helps TNB verify the customer’s demand pattern and ensure that the solar PV design is accurately sized for their operations. This step gives both the client and engineers a solid view of when solar can offset the most energy and whether battery storage is beneficial later.

How to Sizing the DC Cable Tray Trunking

For the DC side of the system, each solar string carries two conductors which is positive (+) and negative (–) which must be routed safely from the rooftop to the inverter. Our engineers ensure that DC cables are always separated from AC cables, helping to reduce electromagnetic interference (EMI), prevent overheating and keep the installation compliant with commercial solar safety practices in Malaysia.

To protect the cables against local weather conditions, we use SuperDyma® coated trunking, which offers superior corrosion resistance and a clean, professional finish on industrial rooftops. We also select cables that comply with solar-rated standards such as IEC 62930 and UL 4703, ensuring long-term durability against heat, UV radiation and mechanical stress.

As part of proper engineering design, the cable fill level is kept below 50%, using standard commercial cable tray widths to allow better ventilation and easier future maintenance. This approach not only keeps the installation looking neat, but it also ensures a safer, more reliable solar PV performance throughout its lifespan.

Real Installation Example

How to Size the AC Cable Tray

After the inverter converts DC from the panels into AC power, the electricity is distributed through four-core AC cables which is red, yellow, blue for the three phases and black as Neutral. An Earth cable is routed separately to ensure proper grounding and safety during fault conditions.

For AC, we use SuperDyma® coated or Hot dip Galvanized preferable cable tray on the AC routes. It provides strong mechanical support and excellent corrosion resistance for rooftop and inverter-room environments in Malaysia.

Inside the cable tray, we use perforated to ensure good airflow and prevent overheating. Meanwhile, we also reserve about 10% – 20% spare width along the route for giving flexibility for rerouting or repositioning inverters during installation without needing to splice new cables.

Conclusions

A solid commercial solar project is not just about installing panels; it is about making sure every single part of the system works safely and efficiently together. From certified power logger installation at the MSB, to analyzing the real load profile, to sizing both DC and AC cable routes correctly, every step shapes the performance and lifespan of the solar system.

With Solana Tec, you get more than just a solar installation; you get engineering done right from day one. Fewer future problems, faster TNB approval, and a solar PV system that actually delivers the savings you expect. That is the Solana Tec difference: precision, reliability, and real performance.

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📈Solar is not just about going green; it is a smart business decision that pays back year after year.

When you choose Solana Tec, you are partnering with a trusted solar specialist in industrial solutions:

✅High-performance solar panels: 25 – 30 years performance warranty
✅Optional BESS battery system: 10 – 15 years lifespan
✅Competitive low-interest solar financing with partner banks
✅Experienced engineering team: installed systems for Restoran Osman, Pusat Latihan Memandu Berjaya, Xin Siang Enterprise, and more
✅End-to-end service: from design to government application & after-sales support

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