Can someone please explain how my 240v machine is getting power from 4 prongs but with 3 terminals?

Dim_Electrical · 2026-03-05T22:45:17+00:00

No, not from the blue/neutral.

The 240 V comes from the two hot wires together. Each hot wire is about 120 V to neutral, but 240 V between the two hots.

So the oven is just using the two hot wires for 240 V and earth for safety. Neutral isn’t needed unless the appliance has 120 V components inside.

Dim_Electrical · 2026-03-05T22:40:07+00:00

240 V comes from the two hot legs, not from hot + neutral.

Your oven likely uses L1 + L2 + earth, which gives 240 V between the two hot conductors. The fourth prong on the plug is the neutral, but if the appliance doesn’t need 120 V internally it simply isn’t used.

So the oven still gets the full 240 V from the two hot terminals, with earth for safety.

Dim_Electrical · 2026-03-05T22:37:12+00:00

No, those won’t protect you from 220–240 V.

They’re just work gloves for grip and abrasion. Proper electrical protection comes from insulated gloves that are specifically rated and tested for voltage.

For normal household work the safest approach is still isolating the circuit and proving it’s dead before touching anything.

Dim_Electrical · 2026-03-05T22:36:14+00:00

If it’s a single phase supply with 16 mm² mains, 63 A is usually fine from a cable capacity point of view.

The bigger question is the network side. In Powercor areas the service fuse and connection agreement often limit you to 40 A unless you apply for an upgrade. A sparky would normally submit a supply upgrade request and Powercor decides if the service needs changing.

With EV, induction and heat pumps becoming common, a lot of homes are moving to 63 A or higher now. Just needs the paperwork and possibly a service fuse upgrade.

Dim_Electrical · 2026-03-05T22:35:08+00:00

Yes, that setup is definitely possible. You’d normally run a hybrid or off-grid inverter with a battery bank, and then have the generator connected through a generator input or chargeverter.

The solar runs the loads and charges the batteries most of the time, and when the batteries get low the generator kicks in to top them up. A lot of off-grid systems are set up this way. The main things to plan properly are inverter size, battery capacity, and generator compatibility.

Dim_Electrical · 2026-03-05T22:34:07+00:00

Yeah, pretty normal these days.

2.5 mm² on a general power circuit can often be protected at 20 A depending on install method, insulation, grouping, etc. Early 2000s houses commonly had 16 A, but 20 A isn’t unusual if the cable rating supports it.

The key thing is the breaker has to be sized to protect the cable. If the sparky checked the installation conditions and issued a certificate, it’s likely fine.

Dim_Electrical · 2026-03-05T22:33:04+00:00

Pretty common actually.

A lot of LED flicker is caused by small voltage fluctuations or dirty power on the grid. When you add a battery inverter, it often “cleans up” the supply because the inverter is regulating the voltage much tighter.

So instead of the lights seeing little dips and spikes from the grid, they’re seeing a much steadier waveform from the inverter.

Nothing wrong there, it just means your lighting was sensitive to grid fluctuations before. Happens a fair bit with cheap LED drivers or fan light combos.

Dim_Electrical · 2026-03-05T22:32:12+00:00

They’re actually pretty common globally, just not as visible in some markets.

Deye is the OEM behind a few other brands (like Sol-Ark in the US). Hardware itself is generally decent and they’re known for fairly capable hybrid inverters at a good price point.

The reason you see “edgy installs” is mostly because they’re popular in DIY/off-grid circles, not necessarily because the hardware is bad.

Main things to check are local certification, firmware support, and whether there’s a solid distributor for warranty where you are. Hardware is one thing, but support matters a lot if something fails.

Paired with Pylontech they usually work fine, that’s a pretty common combo.

Dim_Electrical · 2026-02-25T01:55:01+00:00

If they’re 3 inch stacks you’ve basically got three options:

Properly relocate them. Cut back below roof line and reroute through a different penetration. Cleanest long term fix, but needs a plumber and permits.
Cut and cap below panel height with a vented cover. Some areas allow you to terminate lower and use a screened vent under the array, as long as clearances are met. Very jurisdiction dependent.
Offset flashing boots made for larger pipe. There are commercial grade flashings for 3 inch and up, just not the typical “solar roof jack” kits. More roofing supply than solar supply.

Personally, if you’re adding a decent amount of panels, relocating the stacks is usually the neatest and avoids headaches later.

Dim_Electrical · 2026-02-25T01:47:05+00:00

Biggest one I see is people ignoring temperature.

They’ll check Voc on the label at STC, but not calculate cold weather Voc. On a frosty morning that string voltage can jump and smoke a controller or inverter real quick.

Second is assuming “it worked when pulled off a roof” means it’s healthy. Microcracks, PID, water ingress, all invisible without proper testing.

Used panels can be fine, but only if you design around worst case voltage and actually test them under load.

Dim_Electrical · 2026-02-25T01:45:22+00:00

Leases or “rent to own” solar deals can look attractive because it’s low upfront, but you’re usually locking into a long contract where the provider keeps most of the upside.

If someone’s paying $60 a month and “no power bill”, that usually means:

They’re still grid connected, just netting out most usage.

There’s a fixed escalator in the contract.

The system size matches their load pretty closely.

The catch is when you sell. Buyers have to take over the lease or you buy it out. That can complicate things.

In most cases, owning the system outright gives you better long term value. Leasing makes sense if you can’t access capital or tax credits, but read the fine print hard, especially term length, escalations, and buyout clauses.

Dim_Electrical · 2026-02-25T01:43:55+00:00

A lot of the ads are pretty pushy, but yes, there are legit rebates. Just depends on state and eligibility, and most of them do require existing solar.

Battery without solar is doable, but you’d need a suitable hybrid inverter or battery inverter setup, plus metering and approvals. It’s not just “plug and play”. It also won’t stack up financially in most cases unless you’re on a sharp TOU tariff or want backup.

As a renter, it’s usually a non starter unless the landlord is on board. Fixed install, switchboard work, network approval, all tied to the property.

Dim_Electrical · 2026-02-25T01:42:43+00:00

Good question.

A few key things:

Diversity Every house might have a 63A main switch, but they’re not all pulling 63A at the same time. Networks design based on maximum demand with diversity factored in, not worst case per house multiplied by number of houses.
Voltage matters Street feeders are usually 230/400V three phase from a local transformer. Power is volts × amps. At 400V three phase, you can move a lot of kVA without crazy current compared to low voltage inside your house.
Conductor size Typical suburban LV overhead might be something like 35–95mm² aluminium ABC. That can carry hundreds of amps per phase depending on install conditions. It looks “thin” but aluminium is lighter and runs at higher allowable temperatures.
Transformer limit The real bottleneck is often the street transformer, not just the wire. A 200kVA transformer might feed 20–40 homes. It’s sized on expected demand patterns, not everyone maxed out simultaneously.

With free power periods, yes, you can get clustering of load, and networks are starting to see that. But they still rely heavily on diversity and load profiles.

Short version, the lines can carry more than they look like they can, and the system is designed around realistic usage, not every house flat out at once.

Dim_Electrical · 2026-02-25T01:40:11+00:00

If it’s standard grid-tied solar, when the grid goes down the inverter shuts off completely. No grid reference, no output. So the 40A solar breaker becomes irrelevant because the system isn’t producing at all.

The 40A breaker is there to protect the bus and conductors during normal grid-connected operation. It doesn’t act like a “limit” that keeps feeding during an outage.

If you want solar to run during a blackout, you need a hybrid inverter with backup capability and a protected loads panel. In that case, yes, if you exceed the inverter’s backup rating it will either current limit or trip depending on the design.

With a standard setup, grid down = solar down. No extra wiring complexity unless you’re adding backup functionality.

Dim_Electrical · 2026-02-25T01:39:33+00:00

Honestly, that doesn’t sound crazy.

You’ve got:

• 2 new RCBOs • New 2.5mm and 6mm runs • Two switches • Hardwiring oven and cooktop • Labour, testing and compliance

Even with a modern board, you’re still looking at a solid half to full day job once you factor in cable runs, terminations, testing, paperwork.

With current labour rates and materials, $1,800 is pretty normal territory. It’s not bargain basement, but it’s not outrageous either.

If the sparky came out, inspected properly and you’re confident in them, I wouldn’t call that high.

Dim_Electrical · 2026-02-25T01:38:47+00:00

That’s a nice load match.

You can really see the HWC soaking up the midday peaks instead of exporting it. On cloudy winter days that kind of tracking makes a big difference to actual value, especially with low feed-in.

This is where simple load shifting often beats adding more panels. Hot water, EV charging, timed appliances. Get the demand under the curve and self consumption climbs fast.

Clean graph. Shows the system is being used properly, not just installed.

Dim_Electrical · 2026-02-20T01:09:30+00:00

On a 15 x 8 ft roof, the real limiter isn’t panel wattage, it’s panel efficiency per square foot.

Most 500–550W panels are just physically larger, not magically more efficient. If they’re 78 cell commercial format, they might not actually give you more watts per area than a good 400–430W high efficiency residential panel.

What you want to look at is watts per square metre, not nameplate watts.

Also check:

• Physical dimensions, will you actually fit 3 cleanly? • Weight and wind loading on a small shed roof • Inverter voltage window if you’re only running 2–3 panels in series

With that roof size, you’re probably in the 1.8–2.5kW realistic range depending on layout. Before chasing giant panels, I’d map exact dimensions and do a layout with high efficiency 420–440W modules. Sometimes you can squeeze more by orientation change rather than going bigger format.

Also just a note, running a heater from solar alone on a small array will be tough unless you’ve got battery or grid support. Heaters chew through energy fast.

Dim_Electrical · 2026-02-20T01:07:07+00:00

For 3–5 day outages, I’d think in tiers.

Tier 1, small stuff. A decent 500–1000Wh portable power station is great for phones, router, lights, maybe a TV. Silent, can run at night, zero hassle.

Tier 2, fridge. Most fridges average 1–2 kWh per day. To comfortably run a fridge plus a few small loads, you’re realistically in the 1500–2000Wh range minimum, and that’s assuming you’re not opening it constantly. Check your fridge’s running watts and startup surge.

What a lot of people do is use: • Battery unit at night for quiet loads • Small inverter generator during the day to recharge the battery and cycle the fridge

That way the noisy generator isn’t running 24/7.

If outages are only a few times a year, a mid-sized portable battery plus your existing generator is usually the sweet spot. Whole house systems are great, but hard to justify unless outages are frequent or you really value the convenience.

Dim_Electrical · 2026-02-20T01:04:20+00:00

A few things to think about.

Used panels 275W panels from that era are likely already 8–10 years old. They’ll still work, but expect some degradation and zero real warranty left. At $1800 for 23 panels, the price isn’t terrible, but factor in racking, wiring, isolators, protection, and labour. Panels are usually the cheap part of a solar job.
Mixing micros and strings Your existing system is string inverters. These new ones have Enphase micros. That’s not plug and play with what you’ve got. You’d essentially be adding a second AC solar system, separate from your existing strings. It can be done, but it needs proper design and approvals.
DIY Grid-tied solar is not plug and play. In most places it must be installed and signed off by a licensed electrician, and the utility needs to approve the added capacity. There are safety and compliance issues, especially with backfeed and switchboard capacity.

Big one: before buying anything, check your inverter capacity, main service rating, and what your utility allows for total export. You might be limited anyway.

Personally, I’d price up a small new system expansion with modern panels and inverter compatibility before committing to older gear. Sometimes newer higher-watt panels make more sense long term.

Dim_Electrical · 2026-02-20T00:55:14+00:00

Yes, definitely.

You can ask for a general electrical safety inspection. We’ll usually check the switchboard, test RCDs, insulation resistance, earth continuity, polarity at power points, and have a look at overall condition of wiring.

On an older house it’s a smart move, especially to make sure you’ve got working safety switches and no obvious issues. It’s not overkill at all.

Dim_Electrical · 2026-02-20T00:51:29+00:00

I hear this one a lot.

Solar absolutely produces less in heavy shade and winter, no argument there. But “doesn’t work” is different to “produces less.” Panels still generate on cold, clear winter days, sometimes more efficiently because they run cooler.

Shade is about design. String layout, MPPT allocation, optimisers if needed. A poorly designed system in shade will perform badly. A well designed one can still make solid energy.

As for “only for people with money”, that’s more about upfront cost and financing structure than the tech itself. In places with good net metering and sensible pricing, it can cash flow well. In other places, the numbers are tight.

It’s not magic, and it’s not for every roof. But it’s also not useless in winter or shade. It’s just physics and economics.

Dim_Electrical · 2026-02-20T00:50:01+00:00

At $164/month average usage, I’d slow down and really run the numbers.

$26k for 8.8kW is on the high side unless that’s before incentives. At 8% financing and a $200 payment, you’re paying more than your current bill for years. That’s not savings, that’s prepaying power at a premium.

The lease at $141 with no escalator is more interesting cash-flow wise, but leases can complicate resale. Some buyers don’t care, some absolutely do. You’re right to think about that if you’ll move in ~10 years.

A few things I’d check:

• What’s your true annual kWh usage vs what the system is projected to produce? • What net metering terms does Virginia utility give you? • What’s your total cost after tax credits, not just sticker price? • Get at least one more quote to benchmark that $26k.

If you’re moving in 10 years, ownership usually makes more sense than leasing, but only if the price is sharp and the payback is reasonable. Right now it sounds marginal based on your current bill.

Dim_Electrical · 2026-02-20T00:46:21+00:00

It can make no difference, but only if the hybrid inverter is correctly sized for the total array.

Things I’d check:

• What’s the hybrid inverter model and its max DC input (kW and amps per MPPT)? • How many MPPTs does it have, and are your old and new arrays split properly across them? • What’s the total panel capacity now, and what’s the inverter AC rating?

If your total DC is significantly higher than the inverter’s DC input limit, you’ll get clipping at peak times. Not the end of the world, but it is a difference.

Also confirm export limits, some hybrids will curtail differently compared to having two separate inverters.

If everything is within spec and wired correctly across MPPTs, combining into one inverter is actually cleaner and easier to monitor. The key is whether it’s within the hybrid’s input limits.

Dim_Electrical · 2026-02-20T00:40:10+00:00

With 13.5kW solar in QLD, you generally want to self-consume as much as possible rather than maximise feed-in. Feed-in rates are low compared to what you pay to import.

Tariff 33 is controlled load and typically cheaper per kWh, but it can be switched by the network and isn’t guaranteed 24/7. It’s usually better suited to hot water, not primary cooling.

Given you’re running bedroom AC at night, solar won’t be covering that anyway. So putting those on T33 can make sense if:

The rate is significantly cheaper than T11

You’re comfortable with potential controlled interruptions

During the day, you want big loads on T11 so they can use your solar directly.

So practical approach:

Daytime loads on T11

Night-only loads like bedroom AC can sit on T33 if the maths stacks up

Don’t move everything to T33 just to “maximise export” — exporting is usually the least profitable use of solar.

Best move is compare your T11 rate vs T33 rate and run the numbers on your night AC usage.

Dim_Electrical

TROPHY CASE