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18 votes

Are 6 volt fluctuations in a 120 volt home outlet harmful to equipment?

This is typical. Can't exactly say "normal", because if everything is sized and installed correctly then there should not be significant fluctuations. But it is really quite common, ...
manassehkatz-Moving 2 Codidact's user avatar
17 votes

UPS / Battery Question

I think you're seriously looking for trouble if you try to use one set of batteries in two UPSes at the same time. In theory, discharge will be OK - the batteries will be supplying both loads at the ...
manassehkatz-Moving 2 Codidact's user avatar
15 votes

Are 6 volt fluctuations in a 120 volt home outlet harmful to equipment?

You are lucky to have variations that small. Some variation in the grid voltage is inevitable because of how these things work. Wires have resistance, transformers are less than ideal, the load varies....
fraxinus's user avatar
  • 3,199
13 votes

Should a UPS be unplugged when working on the electrical circuit it is plugged in to?

The UPS battery won't be backfeeding into the house service. DC current won't be flowing back through the rectifier diode. I'd be more concerned about doing something wrong with your switch ...
JACK's user avatar
  • 82.3k
11 votes

Can a switchover to backup power be seamless for a whole house?

This already exists COTS The Tesla PowerWall is the most high visibility version, but there are competitors, and you could even knock one together out of golf cart batteries and inverters. What ...
Harper - Reinstate Monica's user avatar
11 votes
Accepted

Should a UPS be unplugged when working on the electrical circuit it is plugged in to?

While this should be acceptable, I have personally found a UPS which backfed 240AV out its input pins. I only found this out when brushing against the exposed pins on the wall plug - That UPS went ...
Criggie's user avatar
  • 10.8k
11 votes

Are 6 volt fluctuations in a 120 volt home outlet harmful to equipment?

All of those fluctuations are normal in regular residential electrical service. Any large loads, AC units, ovens, water heaters can/will cause a drop in your voltage. Power company regulators in their ...
JACK's user avatar
  • 82.3k
10 votes
Accepted

Is there a safe and compliant way to run consumer UPS power through house wiring to an outlet?

Yes. You can run an isolated electrical line, using normal in-wall wiring methods, from a single inlet to outlets. The inlet will need to be in the NEMA family. A C13 inlet won't cut it for at least ...
Harper - Reinstate Monica's user avatar
7 votes
Accepted

Why does my Uninterruptible Power Supply produce lower watts on backup battery than line power for my pellet stove?

I can't answer why your UPS won't do the job, but I can give some reasons why some random UPS may not do the job. Basically, mostly it's because a UPS is designed to run a computer, not a bunch of ...
TimWescott's user avatar
7 votes

Replicate "Behind Wall TV Power" - Idea or Explosion?

Inlet/outlet is perfectly reasonable here. A few things to consider: The typical "kit" will be a fixed, relatively short, length. So the right way to do this between floors is full-fledged ...
manassehkatz-Moving 2 Codidact's user avatar
6 votes

Use a 24V LifePo battery in a UPS designed for lead acid batteries?

Ed Beal is correct. The answer based on the information provided is NO. However, there are battery replacements that are advertised as "drop-in" matches for lead-acid versions. They ...
fred_dot_u's user avatar
  • 11.1k
6 votes

Use a 24V LifePo battery in a UPS designed for lead acid batteries?

I would say NO. Yes 24 CFC is 24v and that would not matter but the charging circuitry for lithium ion is radically different than lead acid and using the APC battery charging circuit may cause the ...
Ed Beal's user avatar
  • 103k
5 votes

Should a UPS be unplugged when working on the electrical circuit it is plugged in to?

It depends. Cheaper ones have a single (or two) relays that separate the output from the input when there is no power at the input. Bad news are that the relays CAN stick and even if they are sane, a ...
fraxinus's user avatar
  • 3,199
5 votes
Accepted

UPS on multi-wire branch circuit

The UPS has no way of knowing if it's on a MWBC or not. Once you get down to a 120V feed, it looks the same from the receptacle. Therefore, the UPS can't see anything to flip out about.
Ecnerwal's user avatar
  • 220k
4 votes

How do I wire a single phase 240v APC UPS from US split phase power?

Just wire it up like a table saw. Hot-Hot-Ground. Never use the obsolete and dangerous NEMA 10 connector. Whether you need neutral or not, a 4-wire NEMA 14 connector is always OK, and provides the ...
Harper - Reinstate Monica's user avatar
4 votes

UPS / Battery Question

The units use two 12v 8AH SLA batteries in series and for what they cost to replace I could almost replace the entire UPS units. I live in Hawaii so the shipping cost of lead acid batteries is often ...
Harper - Reinstate Monica's user avatar
3 votes

NEMA 5-20 to 5-15 adapter - is it safe?

You have two possible circuits, and the only way to tell is to see what type of breaker you have. 20 Amp If you have a 20 Amp circuits with NEMA 5-15 15 Amp receptacles, then you should replace the ...
manassehkatz-Moving 2 Codidact's user avatar
3 votes

Are 6 volt fluctuations in a 120 volt home outlet harmful to equipment?

When designing a circuit the rule of thumb is +/- 10% or document. So for example USB specifies 5v so when designing a circuit to run off USB make sure it works from 4.5v to 5.5v. applying the rule of ...
hildred's user avatar
  • 887
2 votes

Should a UPS be unplugged when working on the electrical circuit it is plugged in to?

You should not be too concerned, the UPS supplies power to the outlets on the UPS, not to the circuit it is plugged into. When the circuit is opened, the UPS will provide battery backup to the ...
Programmer66's user avatar
  • 2,752
2 votes

Is this UPS Socket Defective?

It's a sourcing problem. The problem is, those "everything sockets" are impossible to make in a safe and reliable form... and as such, UL will never approve one. Because of that, there's no ...
Harper - Reinstate Monica's user avatar
2 votes

Is this UPS Socket Defective?

That is a valid type of socket. See the APC manual for the BX-1400 MS. However, I would be extremely careful plugging any US type B plugs into this UPS. As far as I can tell, this is a 230V UPS. The ...
manassehkatz-Moving 2 Codidact's user avatar
2 votes

Spark/Arc observing while connecting battery to charge controller

Because you're doing it with the power on. That is to say, during daytime. The arc should go away if you turn off the solar panel. Either throw a tarp over it or wait til night. Also, try to get ...
Harper - Reinstate Monica's user avatar
2 votes

Is there any way to use an Uninterruptible Power Supply properly when there's no ground wire in the outlet?

While a UPS, and many surge protectors as well, will show wiring faults equivalent to a magic 8-ball, a UPS should never actually use ground, except if there is a true fault. A brownout or blackout ...
manassehkatz-Moving 2 Codidact's user avatar
2 votes

Is there a safe and compliant way to run consumer UPS power through house wiring to an outlet?

Here I'm planning a nice implementation of the advice in the accepted answer. This plan provides raw and UPS power to the basement location and also through existing house wiring to a den outlet. It ...
jay613's user avatar
  • 40.5k
2 votes

NEMA 5-20 to 5-15 adapter - is it safe?

If your circuit is a 20 amp / 12awg wire it would be safe to replace the receptacle. Using those 20-15 amp devices is not considered safe and you probably can only find them on line because they would ...
Ed Beal's user avatar
  • 103k
2 votes

Home UPS: grounding, isolating, connecting to subpanel

DC is difficult to interrupt, unlike AC which goes to zero volts 100 or 120 times per second. However, 250A DC Circuit Breaker does bring up results these days. Your arrangement of paralleling 3 small ...
Ecnerwal's user avatar
  • 220k
2 votes

Can a Modified Sine Wave input damage an OLED TV?

If you have a particularly expensive TV then consider spending more on a better UPS; albeit I'm seeing 600 watt models for only $200. Anyways: It’s important to understand that both types of UPS ...
MonkeyZeus's user avatar
  • 16.7k
2 votes

Can a Modified Sine Wave input damage an OLED TV?

A surge protector is not a UPS A surge suppressor has some electronics kit inside to try to suppress the kind of surges that damage equipment. It has one job. Now when power is cut and when it's ...
Harper - Reinstate Monica's user avatar
2 votes

Replicate "Behind Wall TV Power" - Idea or Explosion?

Yes it's possible to carry out this idea in a safe and electrical code compliant way. One option is to buy a UL/ETL certified kit like the one you've linked to. It can also be done with off-the-shelf ...
Greg Hill's user avatar
  • 31.3k
2 votes
Accepted

Replicate "Behind Wall TV Power" - Idea or Explosion?

I have an idea that is too much for a comment. I don't have the code knowledge to confirm if it is allowable, or the time to do the research. I hope more knowledgeable members of this community will ...
Aldus Bumblebore's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible