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Non-engineer here. Well, not the electrical kind.

About once a week the breaker to my office (read: gamer cave) trips. I just noticed that our 70 inch TV, 2 x Echo Studios, etc. in the living room on the other side of the wall also go out. There's our problem: Two rooms, each with major entertainment systems are both tied to the same breaker. I noticed that when I play computationally expensive games it seems to more often trigger the breaker as my GPU and CPU draw more power, so I wonder: Would some small uninterruptable power supplies between my power strips and the walls for the major power draw appliances potentially fix the issue?

The same way batteries in Satisfactory (simulation game) help my electrical grid not spike above maximum production, by being able to offer energy to spikes while drawing a more consistent amount from the wall.

Is there a certain type of power supply that would accomplish this, while others wouldn't?

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    \$\begingroup\$ What kind of breaker? At my home I have all outlets 230v@16A = cca. 3.5kW. I don't thin a computer can "eat" all that electricity. \$\endgroup\$ May 3, 2021 at 17:11
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    \$\begingroup\$ Sorry should've clarified, it's a (750W) power supply PC, 70 in (110W) TV, Echo Studio sound system (330W x 2), and 1500W heater, which I use even in the summer, might be cold blooded. I'm drawing quite a bit. Takes trip to breaker box... Doesn't seem to say the breaker specs on the box. \$\endgroup\$
    – J.Todd
    May 3, 2021 at 17:40
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    \$\begingroup\$ Are you at 110V or 220V or what? And you're saying the circuit breaker has no 5, 10, 15, 20, or 30 Amps rating indicated on it? It's usually molded into the switch itself, but should be there. Perhaps buy a Kill-A-Watt to see how much each contraption is actually drawing? (especially the heater). \$\endgroup\$ May 4, 2021 at 3:13
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    \$\begingroup\$ @J.Todd Note that the "330 W" rating of the sound system doesn't have anything to do with power consumption. It's just a marketing figure ("peak" or "music" power). Actually pumping 300 Watts into a speaker system for any appreciable time would make everyone in your house deaf immediately. (Plus require a whole lot of noisy active cooling to dissipate all the heat.) \$\endgroup\$
    – TooTea
    May 4, 2021 at 8:00
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    \$\begingroup\$ It's the heater. Just move it. The heater takes an entire circuit of its own, leaving room for only a few lights. It also doesn't need an expensive UPS. \$\endgroup\$ May 4, 2021 at 12:28

6 Answers 6

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Home UPS aren't designed for peak-shaving. Any system that could do that would have to know what the load is on the entire circuit (i.e. what the rest of the loads are drawing) and then try to supply additional power onto an active bus...you see where this is going. Much easier and very likely cheaper to put in an additional circuit. Do not attempt to replace the breaker with a larger one as this increases the chance your wiring will catch fire.

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A computer + screen + audio should never trip a breaker, you are talking less than 1 kW even with hard out gaming (note: does not include mining). It's your heater... Call an electrician and get another socket in your room on a different circuit breaker or get a heat pump fitted to the bat cave.

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  • \$\begingroup\$ "you are talking less than 1 kW even with hard out gaming" If you add up the wattages of the systems he mentions in his comments, aside from the heater, he's drawing about 1200 W of power. Upvoted for "call an electrician", though. \$\endgroup\$
    – nick012000
    May 4, 2021 at 5:31
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    \$\begingroup\$ @nick012000 those are marketing numbers. If the sound system actually used full power for some time it would melt and OP would be deaf. \$\endgroup\$
    – Rokta
    May 4, 2021 at 6:33
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    \$\begingroup\$ Cheapest solution.. put the heater on a (good!) extension cord plugged in another room that has its own breaker.. \$\endgroup\$
    – WooShell
    May 4, 2021 at 8:30
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    \$\begingroup\$ @WooShell I'd actually be more inclined to run the smaller stuff off an extension cable, or move the heater across the room if there's a socket there on another circuit. \$\endgroup\$
    – Chris H
    May 4, 2021 at 10:58
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    \$\begingroup\$ @Rokta You don't need to draw full power "for some time" to trip the breaker, a short surge when all components draw the max rated power is enough. Also, who knows what GPU they have, maybe this one /sarcasm \$\endgroup\$ May 5, 2021 at 11:53
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Some big (>10kW range) full-conversion (read: stunningly expensive!) UPS'es can be programmed to limit the ingress power and to use the batteries to fill the gap between the supply and demand for short periods. Pretty much useful when the whole thing is backed by a generator as well. And pretty much of a surprise when you get a low battery alarm with no single power issue in the last few months.

On the other hand, the usual type of line-interactive UPS for home/office use generally will exacerbate the peak load problem. First, it has its own power consumption of ~3-5% of its rated load and second, it likes to transfer the whole load at once between the batteries and the mains line. It then consumes additional ~10% of its rated power to recharge the batteries.

What can you do:
Get help from an electrician. The problem may be:

  1. a failing breaker
  2. a failing PSU tripping the GFCI because of a developing ground leak (you do have GFCI protection, right?)
  3. a real overload of the breaker, caused by sharing the breaker with unexpected other appliances (like, say a fridge) or the breaker (and the wires!) being too weak for the purposes intended
  4. another problems like arcing somewhere deep in the walls
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    \$\begingroup\$ +1 for being the only answer which actually answered the question fully. \$\endgroup\$
    – JBentley
    May 4, 2021 at 10:31
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    \$\begingroup\$ A comment on the question by the OP makes it clear that the issue in this case is "a real overload of the breaker, caused by sharing the breaker with --unexpected-- other appliances" (the OP clearly knows the heater is there, so it's not unexpected to them, just to other people reading the question). The OP's comment indicates that there's a 1500W heater being used on the same circuit. \$\endgroup\$
    – Makyen
    May 4, 2021 at 16:51
  • \$\begingroup\$ Are typical home UPSes line-interactive, though, rather than switching over a relay when they need to cut in? Mine (APC Back-UPS Pro 1300) definitely has a relay that makes a big click when it switches to battery power. But its feature list also mentions: Green mode - Patent-pending operating mode that bypasses unused electrical components in good power conditions to achieve very high operating efficiency without sacrificing any protection. which may indicate that previous models wern't totally passive \$\endgroup\$ May 4, 2021 at 18:14
  • \$\begingroup\$ (It also has Boost and Trim features to correct for line voltage without just switching to battery, so it has some capabilities, but could still be switching in a transformer). As a home UPS, I wouldn't be bothered if power was cut for a cycle or so; my computer power supplies have good enough capacitors to not reset the computers. \$\endgroup\$ May 4, 2021 at 18:18
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    \$\begingroup\$ I think line-interactive means exactly this - the big relay with its finite switchover time plus some spike filtering and boost/trim. Switching is done in frequency/phase tollerant manner. Offline is the same with less inteligent switching and prone to skipping a cycle or two. Online is a rectifier + inverter always on with a battery in between. The patented bullshit is to disconnect the big iron transformer from the mains when no one needs it, in a way it can quickly engage back without the big "BRRrrrr" as earlier models did. 2 more relays + more logic to control them minus few W standby \$\endgroup\$
    – fraxinus
    May 4, 2021 at 18:49
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Your idea isn't going to work. It would work for short-term peak loads (like making toast)... but all your loads are continuous.

Sorry should've clarified, it's a (750W) power supply PC, 70 in (110W) TV, Echo Studio sound system (330W x 2), and 1500W heater, which I use even in the summer, might be cold blooded.

US/Canada power is 120V actually.

So that means 6.25 amps, 0.9A, 2.75A and 12.5A respectively.

Same concept works for other places, just factor for your power (100V Japan, 127V Brazil, 230V most of world).

I'm drawing quite a bit. Takes trip to breaker box... Doesn't seem to say the breaker specs on the box.

It's right on the handle!

It will say 15 or 20. Those are amps.

enter image description here

Amps is current flow. Volts is pressure/"head".

Look at your device's nameplate. Figure out device amps either by

  • reading amps directly off the nameplate or
  • looking for a "VA" figure and divide by 120 volts or
  • looking for a "watts (input)" and divide by 120 volts

VA is an improved "watts" which reflects what loads actually draw in amps.

You could've worked it backwards and multiplied breaker handle x 120 and figured on watts/VA ... either way works. I like amps. Small numbers.

Now, every appliance has an "amps" number between 0 and 12.5.

Write it on the appliance if you must.

Back to the breaker handle. What's the number? Don't exceed it.

Not rocket science, my girlfriend does it every day. "Crock pot 2, heater 12. Want toast (7)? Set heater to low (7)."

Can I upgrade the circuit?

No, but you can add another circuit. Either hire an electrician, or honestly it's possible to learn to safely and legally DIY home electrical. Being an engineer gives you an edge since you have a sharp mind, and NOT being an electrical engineer means you'll accept Code wiring standards without argument (they make no sense to EEs at first; so EEs have a lot to unlearn).

Can I upgrade the circuit to more amps? NO. The breakers protect the wires, and the wires can't handle more amps.

Can I upgrade the circuit to more VOLTS without changing the wires? Maybe. And you'll get twice the practical power if you do. Building codes require 120V sockets in certain places. If you don't nee this circuit to meet that standard, you can simply re-mark the white wire as a ot, change the sockets from NEMA 5-15 to NEMA 6-15, and the breaker to 240V of same ampacity (It's a wider breaker though).

Some things (PC) can run on both 120V and 240V - check the nameplate spec. Others might need a different wall-wart. The heater is not one of them, but, you can easily buy built-in heaters that do run on 240V. They cost $40 and last for 30 years.



Hint: I know you're in North America because a "1500W heater" is defined by a UL spec relevant to 120V wiring. Most UL-spec 1500W heaters have a "low" setting.

P.S. that 1500W heater costs 20 cents an hour to run.

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  • \$\begingroup\$ It might be possible to DIY, but it also might violate local code, and void your insurance. \$\endgroup\$ May 4, 2021 at 22:58
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    \$\begingroup\$ @ScottSeidman only in NYC and maybe Boston. Most places, the AHJ provides a mechanism to do it legit, just pull a permit and get inspected. My main stack is diy.se. \$\endgroup\$ May 4, 2021 at 23:01
  • \$\begingroup\$ Saying "simply change the sockets from NEMA 5-15 to NEMA 6-15, and the breaker to 240V" is, at best, a simplistic wording for what's required to have a 240V circuit with the wires which were used for 120V. It would be much better to at least say that it's more complicated than you've stated. For example: the 240V breaker won't fit in the same space as the 120V breaker (the 240V breaker will be double the width, and may not be supported by the panel), and the wire which was the neutral needs to be disconnected from the neutral bar, marked, and connected to the other leg of the breaker. \$\endgroup\$
    – Makyen
    May 5, 2021 at 4:52
  • \$\begingroup\$ @Makyen Edited, but none of that is that big a deal, though. I'm not trying to do how-to instructions here. \$\endgroup\$ May 5, 2021 at 5:11
  • \$\begingroup\$ If the circuit has 12 gauge wiring, it MIGHT be possible to upgrade the circuit from 15 amp to 20 amp service. You'd need to replace all the outlets and switches with 20 amp rated outlets/switches, plus make sure every single wire/box in the entire circuit is rated for 20 amps. This is overall not likely, but it is possible. (12 gauge wire costs more than 14 gauge, plus it's thicker, stiffer, and harder to work with, so unless the homeowner specifically requests it (And pays for it) 15 amp circuits will be wired with 14 gauge wire.) \$\endgroup\$
    – Duncan C
    May 6, 2021 at 18:45
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You comment under the question that you're also running a 1500W heater. I'd be very surprised if that's running flat out; it should have a thermostat that causes it to cycle and maintain a comfortable temperature, and that gives you another option.

In that case a smaller heater would be on more of the time, but drawing less peak current. 300-500W should be plenty to keep the room warm unless you're in the Arctic with poor insulation. It will take longer to warm the room up from cold.

With what's cheaply available to buy here in the UK, I'd get a 750W or 1000W heater with 2 or 3 power settings, using the lower/lowest setting most of the time (somewhere between 250W and 500W probably). The highest setting can be used to bring the room up to temperature quickly if really needed. I suspect it won't be really needed, as (and I'm guessing here) you probably get cold during a long session sitting down - the time it takes for you to get cold gives the room time to warm up.

1500W on 110V is over 13A. With the entertainment kit running another 5-8A (estimated, as in practice you won't use the full rated power) you'd get to 18-21A. At 21A a 20A breaker would take a long time (hours) to trip, if ever. A 15A breaker would still take a while to trip , but a 10A breaker should go fairly quickly. A typical (UK-spec) breaker would give you double the rated current for up to a minute or so; a smaller overcurrent could be maintain for tens of minutes. So I reckon you've got a 10A or 15A/16A breaker, which is little more than enough for your heater - and quite possibly you've got too many sockets run off the one breaker.

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  • \$\begingroup\$ Standard household breakers have time delays in the UK? In NA, they don't. \$\endgroup\$ May 4, 2021 at 12:52
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    \$\begingroup\$ @MattTimmermans no, they have trip curves. Apparently all UL-rated breakers do as well though I'm not sure the classes are exactly the same. \$\endgroup\$
    – Chris H
    May 4, 2021 at 13:02
  • \$\begingroup\$ I believe ours are usually just electromagnetic, and don't have that bimetallic strip. At least I've never seen one take more than a second to figure out what it's doing. \$\endgroup\$ May 4, 2021 at 13:08
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    \$\begingroup\$ @MattTimmermans in a short circuit fault, it should be far less than a second. Overcurrent trip can't be instantaneous or many startup currents would be problematic. Loading to 2x rated current would be instructive, but I'm not sure if it's a good idea \$\endgroup\$
    – Chris H
    May 4, 2021 at 13:23
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    \$\begingroup\$ Yes, you're right. Trip curve says it can take 2x for ~10s and 1.2x for ~ 1 minute \$\endgroup\$ May 4, 2021 at 17:03
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I hit the problem with a powerhouse computer and a room air conditioner--and that was before the days of laser printers. The only solution is what I did--hire an electrician to run another line. Since wire is a tiny part of the cost I had him run a 4-conductor wire instead, I got two circuits out of it so the printer is on a separate circuit from the computer.

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