Commercial renovation projects do not always follow an ideal construction schedule.
This restaurant renovation in South Korea was one of those projects. From the beginning, our electrical work was limited to three working days.
The owner had previous experience with electrical and interior work and planned to complete some of the finishing work himself. He asked our electrical team to concentrate on the parts that would be difficult to deal with later: the ceiling raceway, distribution panel relocation, branch circuits, switches, outlets, and power supplies for the restaurant equipment.
We explained that three days would not be enough to complete every electrical detail in the restaurant. The owner understood that and specifically wanted to install the final lighting fixtures himself so he could adjust their positions as the interior progressed.
Project at a Glance
- Three-day electrical work scope for a commercial restaurant renovation
- 70 × 40 mm ceiling raceway installation
- Distribution panel relocation and circuit organization
- Lighting circuits, switches, outlets, and equipment power preparation
- 30 A fryer circuit prepared for later equipment connection
- Two unidentified exhaust circuits diagnosed using resistance comparison and operating-current measurements
Working Around a Three-Day Schedule
A short work period changes how a commercial electrical job has to be approached.
Electrical work was taking place while carpentry, tile work, ventilation work, and other interior work were also progressing. We therefore had to decide which electrical work needed to be completed first, before other trades made those areas harder to access.
The ceiling work was especially important. Once painting and other finishing work advanced, installing the main raceway would become much more difficult.
For that reason, the ceiling raceway and its supports became one of our first priorities.
.png "Electrical Work During Commercial Restaurant Renovation")
Electrical work progressing alongside carpentry during the restaurant renovation.
Preparing the Ceiling Raceway
The raceway materials were ordered in the morning.
While waiting for delivery, we started installing the ceiling support brackets rather than losing time. A laser level was used to establish a consistent installation height across the open ceiling.
The raceway used on this project measured 70 × 40 mm and came in standard 3-meter sections.
For the suspension system, I cut 3/8-inch threaded rods into approximately 500 mm lengths using a cordless band saw.
Using the DEWALT DCN890 for Bracket Installation
One tool that helped us move quickly was a DEWALT DCN890 cordless concrete nailer.
I used 25 mm high-density pins to fasten the support brackets to the concrete ceiling. On this job, that made repetitive bracket installation much faster than drilling and installing a mechanical anchor at every single support point.
I did not rely only on driven pins. At approximately every fifth hanger, I added a heavy-duty wedge anchor as supplemental reinforcement.
The approximately 1-in-5 wedge-anchor arrangement described here was the method used on this particular project. It should not be interpreted as a universal engineering or code requirement. Support and fastening methods must be selected according to the actual substrate, load, fastening system, installation conditions, and applicable local requirements.
.png "Installing Raceway Support Brackets on Concrete Ceiling")
Ceiling support brackets installed on the concrete structure before mounting the raceway.
Installing and Leveling the Raceway
After the hangers were prepared, the raceway sections were installed.
The laser reference was set at approximately 2.8 meters above the floor, allowing the long raceway sections to remain at a consistent height across the open ceiling.
This was visually important because the restaurant used an exposed-ceiling design. With no finished ceiling hiding the electrical and mechanical services, uneven raceway installation would remain visible after the interior work was completed.
The raceway therefore needed to function as an electrical pathway while also maintaining a clean appearance alongside the ventilation ducts and other ceiling services.
.png "Commercial Ceiling Raceway Installation")
The 70 × 40 mm raceway installed across the exposed ceiling using a laser reference for consistent alignment.
Relocating the Distribution Panel
Another major part of the work was relocating the existing distribution panel to its new position.
The branch-circuit wiring was brought into the relocated panel, connected, and identified so the individual loads could be distinguished later.
Clear identification becomes especially useful on a commercial site where lighting, kitchen equipment, exhaust systems, and other loads are concentrated in a relatively small area.
.png "Relocated Commercial Electrical Distribution Panel")
Relocated distribution panel with branch circuits organized for later identification and maintenance.
Final Electrical Work on Day 3
By the third day, the main raceway and panel work had been completed and the interior renovation had progressed significantly.
Our remaining work focused on preparing the restaurant so that the owner could continue the finishing work himself.
We installed outlets at the required equipment locations and prepared the lighting power and switch circuits.
The final decorative lighting fixtures were not installed by our electrical team. The owner wanted to install them himself so he could determine the exact positions as the interior took shape.
Temporary Lighting and Circuit Checks
Instead of installing the final fixtures, we brought the required lighting conductors to their locations and installed the switches that would control them.
Temporary lamps were then connected to some of those prepared circuits.
They served two practical purposes: they provided working light inside the dark interior, and they gave us an immediate visual indication that the newly installed lighting circuits and switches were operating.
The round lamps visible below the spiral ventilation ducts in the photographs are therefore temporary work lights, not the restaurant's final lighting fixtures.
Temporary lamps connected to the prepared lighting circuits provided work illumination and a simple visual function check.
Preparing Power for the 30 A Fryer
One of the larger individual loads was an electric fryer requiring a 30 A power supply.
For this project, we brought a 3-core 6 mm² CV cable to the equipment location but did not make the final connection to the fryer.
Before leaving the cable ready for later connection, the conductors were identified with colored tape:
- Line (L): Brown
- Neutral (N): Blue
- Protective Earth (PE): Green/Yellow
The 3C × 6 mm² CV cable described here is what we used on this specific project. It should not be treated as a universal conductor-size recommendation for every 30 A load. Cable selection depends on installation method, conductor characteristics, ambient conditions, circuit length, protective device, equipment requirements, and applicable electrical rules.
Identifying Two Unmarked Exhaust-Fan Circuits
Near the end of the project, we encountered a small but interesting troubleshooting problem.
The ventilation contractor had brought two electrical connections to us. One belonged to the kitchen exhaust system, while the other belonged to the larger hall exhaust system.
The problem was that the two circuits had not been clearly identified.
I already knew that the hall exhaust motor was significantly larger than the kitchen exhaust motor, so I first used a digital multimeter to compare the resistance of the two motor circuits.
The readings were approximately:
- Hall exhaust candidate: approximately 2.2 Ω
- Kitchen exhaust candidate: approximately 20 Ω
The large difference gave us a useful indication of which circuit was connected to the larger motor. However, I did not treat the resistance measurement as final confirmation.
A handheld multimeter resistance measurement is not a precise method for determining an AC motor's power rating. In this case, however, the two motors were substantially different in size, so the large resistance difference was useful for initial identification. We then confirmed the result by measuring the actual operating current.
Comparing motor-circuit resistance provided the first clue for identifying the two unmarked exhaust connections.
Confirming the Loads by Operating Current
After operating the exhaust systems, I measured the actual current.
The readings clearly separated the two loads:
- Hall exhaust: approximately 6.25 A
- Kitchen exhaust: approximately 1.51 A
These measurements confirmed which circuit belonged to each exhaust system.
More importantly, the measurement changed how I approached the control method.
Operating-current comparison: the larger hall exhaust system measured approximately 6.25 A, while the smaller kitchen exhaust system measured approximately 1.51 A.
Why the Larger Exhaust Fan Needed Different Control
The smaller kitchen exhaust load could be operated using the intended switch arrangement.
The larger hall exhaust system was different.
With an operating current of approximately 6.25 A, I did not want to treat it like an ordinary lighting load and simply run it through a typical lighting wall switch.
A motor is not the same type of load as a lamp. Motor switching must consider not only normal running current but also starting characteristics and the switching rating of the control device.
For the limited scope of this job, the hall exhaust circuit was connected at the breaker. I explained to the owner that a proper magnetic contactor-based control arrangement would be a better way to complete the control system later.
The important result of the measurement was therefore not simply the number 6.25 A. The measurement helped determine how the load should be treated.
Bathroom Lighting Left Ready for Final Finishing
The bathroom was another example of the agreed division of work.
The owner planned to install a dome ceiling later and told us that only lighting power was required at this stage.
We therefore installed one surface-mounted switch and prepared a lighting power point.
Because the bathroom was very dark during construction, we connected a temporary lamp before leaving the site. The owner would later complete the dome ceiling and final lighting installation himself.
A temporary bathroom lamp connected to the prepared lighting circuit before the owner completed the dome ceiling.
What We Actually Completed in Three Days
It would be misleading to say that the entire restaurant electrical installation was completely finished in three days.
That was never the agreed scope.
Because of the owner's budget and his own experience with electrical and interior work, the project was contracted as a three-day electrical work scope from the beginning.
During those three days, our work included:
- Ceiling raceway and support installation
- Distribution panel relocation and circuit organization
- Lighting power circuits and switches
- Outlets at the required equipment locations
- Power preparation for the 30 A fryer
- Identification and connection of the exhaust circuits
- Temporary lighting for work and circuit checks
The final decorative lighting installation, bathroom ceiling finishing, and some other finishing work were intentionally left to the owner.
This distinction is important. A three-day work scope should not be confused with a claim that an entire commercial electrical installation can normally be completed in three days.
Three Practical Lessons from This Project
1. Work Sequence Matters on Renovation Sites
Raceway and other difficult-to-access electrical work need to be coordinated with carpentry, painting, tile, ventilation, and other trades before those areas become difficult to reach.
2. A Measurement Is Useful When It Leads to a Decision
Resistance readings helped us distinguish two unidentified motor circuits, but the operating-current measurements provided stronger confirmation.
Those measurements then influenced how we approached the control method for the larger exhaust motor.
3. Define Exactly Where Your Work Ends
On this project, the owner intentionally took responsibility for the final lighting installation and some finishing work.
Clearly defining what the electrical contractor completes—and what remains for the owner or another trade—is especially important on renovation projects with a limited work scope.
Closing the Three-Day Work Scope
This project was not about trying to complete an entire commercial electrical installation as quickly as possible.
The three-day limit was part of the agreement from the beginning.
Our responsibility was to complete the electrical infrastructure that needed to be handled at this stage, verify the circuits we worked on, identify an unexpected exhaust-fan wiring issue, and leave clearly prepared power points for the work the owner planned to finish himself.
Real renovation work rarely follows a perfect textbook sequence. Existing conditions, other trades, the owner's plans, available time, and unexpected electrical questions all influence the decisions made on site.
Korean Electrical Construction · Field Experience · Safety · Technical Education
Website: electrickorea.co.kr
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