Something stopped. The breaker did not trip, the PLC is in RUN, and nobody knows who to call. This is the most expensive question in a plant, because the wrong trade arrives, diagnoses for two hours, and then tells you it is not their scope.
The dividing line, in plain terms
An industrial electrician owns everything that carries power: the service entrance and distribution, feeders and branch circuits, motor starters and disconnects, drives, transformers, grounding, and the wiring inside a control panel. Their world is voltage, current, protection and code compliance.
A controls technician or automation engineer owns the logic: PLC and HMI programs, communication networks, sequencing, interlocks, data and reporting. Their world is what the machine is being told to do.
The overlap is the panel itself. Both will open it, both will read a schematic, and both will put a meter on a terminal. That overlap is exactly why scope gets blurry.
Match the symptom to the trade
- Breaker trips, fuse blows, burning smell, hot terminal, arcing sound. Electrician. Stop running it first.
- A motor will not turn, hums, or trips its overload. Usually electrician - check supply, winding and starter before blaming logic.
- Drive faults on overcurrent, overvoltage or ground fault. Electrician for the power side, controls for the drive configuration.
- Machine runs but the sequence is wrong, a step is skipped, or a permissive never comes true. Controls.
- HMI frozen, screens blank, values stale. Controls, though check panel power first.
- Network node dropped, drive not communicating. Either - this is where a controls tech with electrical grounding is worth the money.
- Safety circuit will not reset. Both, and it should be treated as a safety investigation, not a nuisance fault.
What Ontario requires
Electrical work in Ontario is regulated. Electrical contractors must be licensed and work must be done by or under the supervision of a licensed electrician, with notification to the Electrical Safety Authority for work that falls under its scope. Industrial maintenance departments can hold a certificate of authorization for in-house work, but the rules are specific and worth knowing before someone's cousin "has a guy".
Practical takeaway: if the work involves permanent wiring, distribution, or anything that has to pass inspection, it needs a licensed electrical contractor. Do not let a controls integrator pull branch circuits on the side, and do not let an electrician reflash a safety PLC.
The five jobs an industrial electrician is actually for
1. Power distribution and capacity
Adding a machine means adding load. Someone has to read the panel schedule, calculate available capacity, size the feeder and protection, and confirm the transformer and grounding will carry it. Getting this wrong is how plants end up with nuisance trips every summer.
2. Motor controls and drives
Starters, contactors, overloads, soft starts and VFDs. The electrical side is supply, protection, cable sizing, grounding and shielding. Cable selection matters more than people expect: an unshielded motor lead run next to signal wiring will inject noise into your analogue inputs and you will spend a week chasing a "PLC problem" that is really a cable routing problem.
3. Control panel build and wiring
Layout, drilling, wireway, terminal numbering, ferrules, torque, point-to-point checks and insulation testing. A panel that is wired neatly is not vanity - it is the difference between a two-hour fault and a two-day one three years from now.
4. Safety circuit wiring
Dual-channel E-stop strings, guard interlocks, safety relays and monitored contactors. The wiring has to match the risk assessment and the required performance level. This is one place where "it works" is not the standard.
5. Inspection, thermography and compliance
Panel thermography finds loose lugs before they become fires. Insulation resistance testing on motors finds winding degradation before failure. Arc flash labelling and documentation keep you compliant and keep your people alive.
Where plants waste money
- Sending a controls tech to a power fault. They will find it eventually, but you paid engineering rates for electrician work.
- Sending an electrician to a logic fault. They will verify every wire is good, then tell you the program is wrong - which is true, and now you have two bills.
- Quoting a retrofit without the electrical scope. The panel needs a new feeder, the drive needs a line reactor, the enclosure needs to be bigger. None of that was in the controls quote, and now it is a change order.
- Replacing parts instead of finding the cause. Three contactors in a month is not bad luck. It is a coil voltage problem, a duty cycle problem, or a mechanism binding.
Questions that save a callout
- Did the breaker trip, or did the machine simply stop?
- Is the controller in RUN, and are there any fault codes?
- Does the fault follow the product, the station, or the shift?
- What changed since it last ran - new recipe, new operator, new part, new firmware?
- Is there a schematic and a program backup in the panel?
Answers to those five usually tell us which trade to send, and half the time they solve it before anyone arrives.
How we scope it
We take the electrical and the controls scope together, because on a retrofit they are one project. One point of contact, one commissioning window, one set of drawings that matches what is actually installed. Licensed electrical work is executed as licensed electrical work - we do not blur that line, and you should not accept a quote that does.