Does a circuit breaker trip when connecting a new PC?
Does a circuit breaker trip when connecting a new PC?
Inrush refers to the initial surge of power required to charge capacitors upon first activation. Generally, a circuit breaker can manage this situation similarly to how it handles the increased load from a refrigerator motor at startup. By reviewing electrical codes, you can discover the specific current requirements for a circuit breaker. Typically, it can withstand a brief spike well beyond its rated capacity. Although the exact magnitude is uncertain, many installations involve high-power devices like window AC units, which generate significantly larger surges.
This concept was clearly outlined in the previous discussion about UPS systems. It’s not only about pure sine waves but also requires "double conversion." It would be more economical to replace the power supply rather than attempting to conceal issues. The breaker should comfortably accommodate a 1500-watt computer power supply.
The first strong current increase happens only when the main power is connected to the ATX power supply unit. It doesn’t repeat until after you disconnect the main and reconnect it again, either by flipping the rear panel switch or unplugging from the wall.
This spike does not occur when you press the power button on a computer case. The surge has already taken place once the circuit from the wall outlet through the rear panel switch was closed.
True. Examining current and speed curves for various breakers shows they won’t trip until the current exceeds 3 to 10 times or even 20 times the rated value.
There are three breaker types illustrated in the diagram below. B is the most sensitive (3x to 5x), D is the least sensitive (10x to 20x).
https://www.ecosoch.com/blogdesc/66c96cc...974bb980df
These breakers use thermal and magnetic mechanisms, but they also include two extra protection features: an arc detector and a ground leakage detector. These add complexity when troubleshooting remotely.
I’m unsure which specific function is causing the trip if it happens unpredictably. Could you share the trip current rating of the breaker? A low rating (10A) suggests a higher chance of tripping, while a higher rating (20A) means less sensitivity. Ideally, having the exact part numbers would help look up the data sheets.
If I had modern MCBs on my main service panel, each circuit would be rated at 32A. With a 240V 50Hz supply, that equals about 7.68kW per ring main. Since I lack leakage or arc detectors, I avoid unnecessary disconnections.
During a major short circuit, the fuse in my utility panel trips, and I have to rewire the large ceramic fuse holder with new wire (a somewhat outdated method). Perhaps one day I’ll install MCBs.
I hope a properly trained electrician understands the significant current spike that appears in many ATX power supplies, though they might not be aware of its impact. The smallest surge recorded in ATX PSU test reports is 20A, while the largest reaches 110A. Usually it falls between 40 and 80A.
If I use a 10A breaker and push 60A through it, it’s unlikely to trip, though it could. ATX power supply spikes are brief, and the energy often isn’t sufficient to trigger the breaker. If the spike exceeds 100A, the outcome is uncertain for a 10A breaker.
As Tom notes in his PSU testing, these current surges can influence switches, fuses, and breakers, and I’ve replaced several inexpensive main switches with melted contacts due to repeated shocks.
Unless you're prepared to use a non-AFCI breaker, I concur with Bill; it's more economical to purchase PSUs from retailers that allow returns, testing them individually until compatibility is found. Any standard standby UPS will simply continue supplying power until the voltage drops or rises excessively (including line-interactive models which attempt voltage regulation and try to synchronize with the inverter’s output), thereby preventing the breaker from detecting a PSU load it dislikes. GFCI protection is acceptable, but with certain conditions:
These devices significantly prolong the life of connected surge protectors by interrupting power as soon as surges are detected, which also safeguards equipment on the same circuit even if not directly connected to a surge protector. However, this means you can't tolerate minor surges for long—though it’s manageable for a gaming PC but less desirable for content creation. This issue occurs occasionally (about once a year here) and is common in Texas due to frequent thunderstorms.
They also shorten the lifespan of UPS batteries, since lead-acid cannot be fully discharged to the manufacturer’s recommended cutoff voltage (which is set too low to ensure adequate runtime). Even when the PC is idle but you’re away when the breaker trips (as most UPS units have built-in surge protection), the battery drains to maintain standby power, including for power bricks. The inverter then operates inefficiently at such low loads, resulting in a surprisingly short runtime. Consequently, you may find yourself returning home with completely drained and damaged batteries—even though the power never actually failed.
By the way, the diagram indicates that the main breakers controlling the rest of the panel are located directly above 1 and 2. According to the NEC electrical code, it only takes up to six throws to shut off all power, allowing firefighters to quickly de-energize the area. Turning off these two breakers leaves the remaining ones without power, making them safe for maintenance. Next to the diagram is a list of suitable breaker types.
Purchase an inexpensive kettle with high wattage to check if it causes a circuit trip.
AFCI is a scam created by breaker manufacturers who pushed laws to boost profits. It relies on misunderstandings about how extension cords get damaged, not real safety concerns. The small number of fires caused by people making mistakes seems minor compared to the extra costs everyone pays for these devices. If you challenge this, manufacturers often defend themselves with emotional appeals and misleading images. If my home had the problem, I’d replace the breakers and only consider swapping them back if needed. It might be due to a specific brand affecting power adapters, but it’s likely just a quirky issue tied to certain power supplies. Most new homes built after 2018 must now have AFCI protection.