Inside Your Power Meter And Panel. Today, we’re going to talk about power meters — what’s actually behind them, and how they’re wired. Stick around and we’ll walk you through it.
Understanding the Setup
This particular setup is a 200-amp underground service.
If you haven’t seen our video on underground feeds yet, make sure to check that one out first — I’ll drop a link in the description.
The power comes from the utility pole, runs underground, and then comes up through this protective guard. Inside that guard is a tech cable carrying power into the meter base.
Inside, we’ve got a 250 KCML (MCM) cable — with two hot wires (one black and one red) that carry 240 volts between them. There’s also a white neutral and a #6 green ground wire, which serves as the main ground.
Here in Canada, that main ground bonds at the first point of connection, and you can actually see the bonding screw at the back of the meter base tying it all together.
Bonding and Grounding Explained
From the meter, the secondary conductors head into the house, where they bond to the back of the main electrical panel.
You’ll notice the metal casing around the tech cable has a bond connector that attaches to a lug, ensuring it’s properly bonded to the casing.
It’s important to understand the difference between grounding and bonding:
- The ground connects to earth — and there’s only one true grounding point.
- Bonding connects all metal parts of the electrical system together so that, in case of a fault, current can safely return to ground.
Since this setup transitions from metal conduit to plastic, we have to make sure both metal sections are bonded together properly.
How the Power Flows
In a standard meter setup:
- The line (incoming power) connects at the top.
- The load (power going into your house) connects at the bottom.
The power enters the top terminals, passes through the meter (which measures your energy usage), and then continues into your home’s panel.
On this job, our journeyman Luke — who’s visiting from the UK — is handling the meter tie-in. You’ll see him connecting the main ground wire to the bonding lug at the back of the meter base.
Line Side and Load Side Wiring
Because this is an underground service, the line conductors come up from below, loop around, and tie into the top lugs of the meter base. Luke starts by installing the neutral in the center, then the two hots (black and red) on either side.
It doesn’t matter which side the red or black goes on — it’s a split-phase system, not three-phase — as long as there’s 240 volts between them.
Since we’re using aluminum wire, we apply Noalox (anti-oxidation compound) to prevent corrosion and ensure a solid connection. After tightening the lugs, we always recheck and retorque them once everything’s set.
Secondary Side and Panel Connections
Next, we move to the secondary side, where the power heads into the main panel inside the house.
We tie the neutral to the center lug and the two hots to the side lugs, leaving the #4 bond wire connecting the meter casing to the panel casing.
Inside the main panel:
- The #4 bond wire connects to the metal enclosure.
- We remove the bonding screw, since this is the second point of connection — we can’t have the neutral and ground bonded together again here.
- The main neutral goes to the neutral bus, and the two hots connect to the main breaker.
Canada vs. UK Wiring: A Quick Comparison
Luke mentioned that things are quite different back in the UK.
Over there, electricians don’t typically handle the main service connections — the power company does. They’ll hook the mains into the meter, and the electrician ties into an isolator switch on the customer side.
He also pointed out that most UK homes use copper wiring exclusively, whereas here in Canada, aluminum is still common for service conductors (anything over #8 AWG).
In the UK, power is almost entirely underground, while here in Canada, overhead lines are still very common.
Their panels are also smaller — usually around 16 to 30 circuits — compared to the 40/80-circuit panels we often use in North America.
Finishing Touches: Weatherproofing and Inspection
Once everything is wired, we seal the opening with duct seal to keep out moisture — a required step that inspectors definitely check for here in Canada.
We also drill small drain holes at the bottom of the meter base to allow any water that does get in to escape before installing the cover.
After that, we put the meter cover on, secure it, and once the inspection is complete, the utility company will install the meter itself and seal it.
Final Look
And there you have it — a completed 200-amp underground meter installation!
Now you know exactly what’s behind your power meter and how everything ties together safely and properly.
See you next week on the next one!
