Multiple power strips daisy-chained, code?

[Rich Grise]

Why not use a 'cube tap' on the main outlet? Then plug in both strips
to the 'cube tap' (a cube tap is a single to three adapater).

AKA "octopus outlet"? ;-)

Cheers!
Rich

 

[Joerg]

I don't see any major issues (I presume "Item #4" means _section 4 ??)

Yeah, the number of outlet spec. I've seen that in a lot of
jurisdictions and while they may be old they are often still enforced.

Keep in mind that was a long time ago, 1980.

It's common now for ordinances (building codes) to simply require, by
reference, adherence to NFPA and NEC.

If you are lucky. I remember NFPA 70 Article 110 or something like that
not allowing high amperage loads such as coffee makers on power strips.
Not that this makes a lot of sense either on a power strip that is
properly rated.

Anyhow, I have yet to see a conclusive reason why it's unsafe to
daisy-chain. Not some law but engineering numbers.

 

[StickThatInYourPipeAndSmokeIt]

The thought is that at some point someone will put 10 amps load on the
first strip, then put 10 amps load on the second, and because the
first strip is rated at 13 amps (typically) all heck will break loose.

And that doesn't change a damned thing. A 15 amp circuit will STILL
blow at 15 Amps, and a 20 Amp circuit will still blow at 20 Amps,
regardless of how the load is attached. WHY? BECAUSE THAT IS WHAT THE
BREAKER IN THE PANEL OPERATES AT.

ALSO, each 'strip' is protected unto itself, so BOTH upstream loads and
downstream loads make no fucking difference. That means that the rating
of the strip doesn't mean a damned thing, regardless of what is attached.
If the current exceeds the rating, the strip will blow.

All this fucking fear comes from the decades past when such protections
were not in place. Now... THEY ARE, so stop worrying!

ALSO, add up the consumption of all your devices. I doubt you can get
to a 20 amp draw from ordinary household appliances and electronic
equipment, short of using a fucking pair of hair dryers on the circuit.
Remeber, a 100Watt PC supply does NOT actually use 1000 Watts UNLESS you
have all the outputs of it fully loaded, which has a VERY low likelihood.

 

[Joerg]

Isn't the fire marshal's real concern the daisy-chain??

Well, yes, this was just one example where rules contradict. Codes state
that power strips may not be mounted yet UL blesses one power strip with
mounting holes after the other. Weird, isn't it?

Do you have "arc protection" breakers?

Those have been blessed (by the inspector). AFAIK they are required on
new buildings and large remodel jobs out here.

 

[Archimedes' Lever]

Two strips + surge suppressor.


"UL" is required for temporary use too. UL <> NFPA. NFPA is the
controlling authority in most jurisdictions.

The UL approved mounting holes won't catch on fire. ;-)

Also note that "UL" is often counterfeited.

I can almost assuredly declare that this is only the case with imported
products, typically those from China.

There are not very many, if ANY US manufacturers that pull this lame
shit.

 

[Archimedes' Lever]

Typically, each contact on a strip won't be rated for the full load
of the strip, which is what you're asking from inline strips.

Absolutely incorrect. By LAW (compliance rules), EACH outlet available
on the strip must be capable of handling the full current capacity rating
of the strip. Use a little common sense. Hell, the interconnection
wires inside handle less current than the blades in the outlets do. If
anything inside would fail, it would be the interconnections, not the
outlet itself.

 

[krw]

Yeah, the number of outlet spec. I've seen that in a lot of
jurisdictions and while they may be old they are often still enforced.

Florida is known to be the worst state for such things. ISTR they
were the last state to adopt the NEC as the default and did so
superceding all local regs because each fiefdom had its own stupid
versions and enforcement was uneven (can you say "kickback").
It wouldn't surprise me that this entire reg was reversed by state
statute.

If you are lucky. I remember NFPA 70 Article 110 or something like that
not allowing high amperage loads such as coffee makers on power strips.
Not that this makes a lot of sense either on a power strip that is
properly rated.

Anyhow, I have yet to see a conclusive reason why it's unsafe to
daisy-chain. Not some law but engineering numbers.

The NEC is "written in blood", as they say in the trades. Fatal fires
are investigated by the NFPA and the causes fed back into the NEC.
Everything in there is there because someone died. Perhaps a fire was
caused by a (faulty?) power strip in series. UL, OTOH, tests devices
for safety. Perhaps that's the difference.

 

[krw]

Absolutely incorrect. By LAW (compliance rules), EACH outlet available
on the strip must be capable of handling the full current capacity rating
of the strip. Use a little common sense. Hell, the interconnection
wires inside handle less current than the blades in the outlets do. If
anything inside would fail, it would be the interconnections, not the
outlet itself.

Cite. That's certainly not true of duplex outlets (15A contacts).

 

[krw]

I can almost assuredly declare that this is only the case with imported
products, typically those from China.

Exactly the case. Though anything can be (and likely is)
counterfeited, even the Trademark. Why stop at 'UL'?

There are not very many, if ANY US manufacturers that pull this lame
shit.

Duh! Ya think?

 

[Joerg]

Could you just add another couple of duplex outlets on the same
circuit as the existing outlets - then each power bar could be plugged
in to a wall outlet independently. No need to run new circuits from
the breaker panel (as long as you don't go over the breaker's rating.)

Yes, we could but AFAIR code would require one more (and looong) home
run to the panel. Plus a switch because about 10 or so devices must be
turned off after worship and two plus the whole computer enchilada must
be left on.

 

[Archimedes' Lever]

UL says they aren't supposed to be mounted anywhere. From the UL "White
Book":
"Relocatable power taps are not intended to be permanently secured to
building structures, tables, work benches or similar structures ...."

Then mounting hardware is a bit strange.

Not just the hardware. If this is the case, then the manufacture of
ALL power strips that have mounting ears or simple slots incorporated
into their design, which covers nearly all devices currently being made.

 

[Archimedes' Lever]

My understanding:
The NEC (published by the NFPA) has no intrinsic authority. It has to be
adopted by a governmental unit (and is widely adopted, sometimes with
modifications).

The NEC generally requires wiring installed to be "approved". Approval
is by the "authority having jurisdiction", the inspector or governmental
unit. They would normally use listing by UL (or maybe another nationally
recognized testing laboratory).

Once the wiring is installed, OSHA would want equipment that is plugged
in to be UL listed (or equivalent). That should include a church. OSHA
would not cover a home. Fire (and other codes) could also further
restrict electrical requirements.



Maybe Joerg should threaten the fire inspector with a "higher authority".

Name even ONE consumer home that has had a local authority (having
jurisdiction) inspection of the home entertainment system installation.

For that matter, name even one that has been professionally installed,
that was subsequently inspected for conformance by the local jurisdiction
based authority.

 

[Archimedes' Lever]

"Same mentality caused a local dog kennel to smoke or fry 20 some
dogs because power strips were daisy chained. They also assumed a
circuit breaker made it safe."

They also then used power strips that ALSO had no protection
incorporated into them. Not very fucking bright.

If the strips were protected, he could never have reached a current
level that would have exposed the faulty "Chinese made" breaker.

Why circuit breakers which fail compliance ever make it into the market
is beyond me. How online purchases of such devices can even be legal is
also beyond me.

 

[Archimedes' Lever]

Do you have the details of what actually started the fire? After all, you can
certainly start fires with a dozen wall-mounted outlets just as readily as you
can with a dozen power strips.

Not true at all. You statement should be "You can certainly start a
fire in ANY circuit that has a faulty breaker protecting it.

That way, even a single device or single short event would be protected
against.

Without a viable breaker in the panel, the circuit is not protected,
and any faults cannot be deemed as having been the fault of ANY load
presented to the circuit.

So NO, it does NOT have to do with how you attach a load, it has to do
with how the circuit is protected from an overload condition. If that
doesn't happen, THEN your remark becomes true.

 

[Archimedes' Lever]

All it takes is one wall wart to
melt down.

When was the last time you saw that?

They too must comply, and that means the capacity to fold back upon a
dead short scenario, so that means that ANY load presented to the output
of ANY walwart should NEVER bring the walwart temp up to the melting
point of the plastic it is housed in, AND it should return to normal
operation after the short is removed.

 

[Archimedes' Lever]

Cite. That's certainly not true of duplex outlets (15A contacts).

A 15 Amp duplex outlet must handle the full 15 Amps on EITHER of its
outlet positions.

Also, have you ever even seen the interconnection wires typically used
in power strips? The current variety barely handles the amperage the
strip is rated at.

The best little six outlet power strip I ever saw or used was/is the
Radio Shack unit that was sold back in the 80s. It had hard, solid
outlet interconnects, and used real, 'full bore' outlets, like those used
in housing construction. The ten amp breaker opened up right at the ten
amp limit, without fail.

 

[Archimedes' Lever]

Exactly the case. Though anything can be (and likely is)
counterfeited, even the Trademark. Why stop at 'UL'?


Duh! Ya think?

The power supply co I worked for 'self certified' on their CE mark, but
that was only because we had half our company at a UK facility, and they
had been self certifying for years.

400kV supplies for a couple of decades pretty much had the boys at CE
assured that we knew what we were doing.

ALL of our AC fed gear in the US arm of the company had to get UL
certs, and we had to instruct THEM as to how to work with, and make for
acceptability standards for HV supplies. Before us, they had never had
such certs applied for. Our anode supply made for a hi res medical crt
display for GE had to be certified. UL had to learn from us, what was
involved with supplying HV, and protecting against fault and failure
modes causing external mains side electrical issues.

 

[ehsjr]

There is no requirement that he do so. His opinion is law until
you take him to court. If you like tilting at windmills, go for it
but don't expect to ever win.

Exactly. People should bear in mind it's his ass on the line
when he signs off on an inspection. He'll be in very deep doo-doo
if there's a fire caused by a dangerous electrical installation that
he should have spotted. His authority derives from the government
that pays him, not from the code. He is required to use his own
experience to determine if something that he sees is dangerous,
whether the code specifically prohibits it or not.

In the case of rejecting daisy chained strips, he'd win in court.
He testifies "It's a situation that can easily become dangerous,
where one receptacle is expanded to 5 plus another strip, so he
has 11 receptacles where he started with one. It is begging for
an overload." Or something similar to that. He need not cite
the NEC (or whatever code).

Setting court aside, he looks at it and has those same thoughts.
It screams to him as a potential for overload. He's not about
to sign off on something he sees as dangerous.

Ed

 

[krw]

A 15 Amp duplex outlet must handle the full 15 Amps on EITHER of its
outlet positions.

But they are allowed on a 20A circuit, Dimbulb.

Also, have you ever even seen the interconnection wires typically used
in power strips? The current variety barely handles the amperage the
strip is rated at.

Your point? (No citation seen)

The best little six outlet power strip I ever saw or used was/is the
Radio Shack unit that was sold back in the 80s. It had hard, solid
outlet interconnects, and used real, 'full bore' outlets, like those used
in housing construction. The ten amp breaker opened up right at the ten
amp limit, without fail.

Your point? (Still no citation seen)

 

[Joerg]

When was the last time you saw that?

About three years ago.

They too must comply, and that means the capacity to fold back upon a
dead short scenario, so that means that ANY load presented to the output
of ANY walwart should NEVER bring the walwart temp up to the melting
point of the plastic it is housed in, AND it should return to normal
operation after the short is removed.

But corners are often cut no matter what the rules are. Heck, even Dell
had a major recall on the power supplies for one line of laptop I have here.