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-   -   Rotary phase converter: local ground or all the way to the panel? (https://www.diybanter.com/home-repair/235379-rotary-phase-converter-local-ground-all-way-panel.html)

rpseguin February 27th 08 06:04 PM

Rotary phase converter: local ground or all the way to the panel?
 
Ok.
Thanks for everybody's help in the earlier thread.
The 20HP rotary phase converter is working, but I now need to place it
in the garage, about 70+ feet wiring run distance from the main
breaker panel.

Given the cost of copper wire these days, my inclination is to run
just the two hots to the panel and to put a grounding rod close up to
the garage and run a local ground to it.
I see no reason to run a neutral line from the panel (the machines are
all 3 phase).

I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?

What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? ($ signs get much bigger with the wire gage/diameter :-)

Anybody near San Jose, CA have a spool of #4 or larger gage for
cheap? :-)

Thanks in advance!

[email protected] February 27th 08 06:18 PM

Rotary phase converter: local ground or all the way to the panel?
 
On Feb 27, 12:04�pm, rpseguin wrote:
Ok.
Thanks for everybody's help in the earlier thread.
The 20HP rotary phase converter is working, but I now need to place it
in the garage, about 70+ feet wiring run distance from the main
breaker panel.

Given the cost of copper wire these days, my inclination is to run
just the two hots to the panel and to put a grounding rod close up to
the garage and run a local ground to it.
I see no reason to run a neutral line from the panel (the machines are
all 3 phase).

I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?

What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? �($ signs get much bigger with the wire gage/diameter :-)

Anybody near San Jose, CA have a spool of #4 or larger gage for
cheap? :-)

Thanks in advance!


bad idea it can create a ground loop and hazardous vlotages between
grounds, install a ground rod, but definetely bond it to the main
building ground.

Matt Stawicki February 27th 08 07:09 PM

Rotary phase converter: local ground or all the way to the panel?
 
On Wed, 27 Feb 2008 09:04:23 -0800 (PST), rpseguin
wrote:

Ok.
Thanks for everybody's help in the earlier thread.
The 20HP rotary phase converter is working, but I now need to place it
in the garage, about 70+ feet wiring run distance from the main
breaker panel.

Given the cost of copper wire these days, my inclination is to run
just the two hots to the panel and to put a grounding rod close up to
the garage and run a local ground to it.
I see no reason to run a neutral line from the panel (the machines are
all 3 phase).

I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?

What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? ($ signs get much bigger with the wire gage/diameter :-)

Anybody near San Jose, CA have a spool of #4 or larger gage for
cheap? :-)

Thanks in advance!


I used 6/3 SO cable for mine. For that 70+' distance however, you
might be better off with 4/3. The SO cable might cost a little more,
but it makes for a clean installation. Unless you plan to run conduit.

Also keep in mind, if you run wire instead of SO cable, your ground
doesn't need to be as big as the hot wires. A #10 ground wire will
work.

Matt

Matt Stawicki February 27th 08 07:26 PM

Rotary phase converter: local ground or all the way to the panel?
 
On Wed, 27 Feb 2008 18:09:10 GMT, Matt Stawicki
wrote:

On Wed, 27 Feb 2008 09:04:23 -0800 (PST), rpseguin
wrote:

Ok.
Thanks for everybody's help in the earlier thread.
The 20HP rotary phase converter is working, but I now need to place it
in the garage, about 70+ feet wiring run distance from the main
breaker panel.

Given the cost of copper wire these days, my inclination is to run
just the two hots to the panel and to put a grounding rod close up to
the garage and run a local ground to it.
I see no reason to run a neutral line from the panel (the machines are
all 3 phase).

I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?

What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? ($ signs get much bigger with the wire gage/diameter :-)

Anybody near San Jose, CA have a spool of #4 or larger gage for
cheap? :-)

Thanks in advance!


I used 6/3 SO cable for mine. For that 70+' distance however, you
might be better off with 4/3. The SO cable might cost a little more,
but it makes for a clean installation. Unless you plan to run conduit.

Also keep in mind, if you run wire instead of SO cable, your ground
doesn't need to be as big as the hot wires. A #10 ground wire will
work.

Matt


Forgot to mention......
Go all the way to the panel with the ground.

Matt

Gunner[_2_] February 27th 08 07:42 PM

Rotary phase converter: local ground or all the way to the panel?
 
On Wed, 27 Feb 2008 09:04:23 -0800 (PST), rpseguin
wrote:

Ok.
Thanks for everybody's help in the earlier thread.
The 20HP rotary phase converter is working, but I now need to place it
in the garage, about 70+ feet wiring run distance from the main
breaker panel.

Given the cost of copper wire these days, my inclination is to run
just the two hots to the panel and to put a grounding rod close up to
the garage and run a local ground to it.
I see no reason to run a neutral line from the panel (the machines are
all 3 phase).

I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?

What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? ($ signs get much bigger with the wire gage/diameter :-)

Anybody near San Jose, CA have a spool of #4 or larger gage for
cheap? :-)

Thanks in advance!



You can get by with #10 Green..but...

Go all the way to the panel.

While life is cheap, replacing you can be expensive

Gunner

[email protected] February 27th 08 07:51 PM

Rotary phase converter: local ground or all the way to the panel?
 
On Feb 27, 1:42�pm, Gunner wrote:
On Wed, 27 Feb 2008 09:04:23 -0800 (PST), rpseguin





wrote:
Ok.
Thanks for everybody's help in the earlier thread.
The 20HP rotary phase converter is working, but I now need to place it
in the garage, about 70+ feet wiring run distance from the main
breaker panel.


Given the cost of copper wire these days, my inclination is to run
just the two hots to the panel and to put a grounding rod close up to
the garage and run a local ground to it.
I see no reason to run a neutral line from the panel (the machines are
all 3 phase).


I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?


What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? �($ signs get much bigger with the wire gage/diameter :-)


Anybody near San Jose, CA have a spool of #4 or larger gage for
cheap? :-)


Thanks in advance!


You can get by with #10 Green..but...

Go all the way to the panel.

While life is cheap, replacing you can be expensive

Gunner- Hide quoted text -

- Show quoted text -


copper is costly but why install something you know wouldnt pass code,
or a future home inspection.

do it right do it once then relax and forget about it

rpseguin February 27th 08 08:27 PM

Rotary phase converter: local ground or all the way to the panel?
 
On Feb 27, 10:51 am, " wrote:
On Feb 27, 1:42�pm, Gunner wrote:



On Wed, 27 Feb 2008 09:04:23 -0800 (PST), rpseguin


wrote:
Ok.
Thanks for everybody's help in the earlier thread.
The 20HP rotary phase converter is working, but I now need to place it
in the garage, about 70+ feet wiring run distance from the main
breaker panel.


Given the cost of copper wire these days, my inclination is to run
just the two hots to the panel and to put a grounding rod close up to
the garage and run a local ground to it.
I see no reason to run a neutral line from the panel (the machines are
all 3 phase).


I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?


What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? �($ signs get much bigger with the wire gage/diameter :-)


Anybody near San Jose, CA have a spool of #4 or larger gage for
cheap? :-)


Thanks in advance!


You can get by with #10 Green..but...


Go all the way to the panel.


While life is cheap, replacing you can be expensive


Gunner- Hide quoted text -


- Show quoted text -


copper is costly but why install something you know wouldnt pass code,
or a future home inspection.

do it right do it once then relax and forget about it


I'll do it the right way and run it to the panel.

I'm just renting the house, which, by the way, doesn't have any
grounded outlets other than a couple of GFIs in the bathrooms.
The landlord did put 3 prong grounded receptacles in, even though
there's no ground wires in any of them.


Lew Hartswick February 27th 08 08:48 PM

Rotary phase converter: local ground or all the way to the panel?
 
rpseguin wrote:

Ok.
Thanks for everybody's help in the earlier thread.
The 20HP rotary phase converter is working, but I now need to place it
in the garage, about 70+ feet wiring run distance from the main
breaker panel.

Given the cost of copper wire these days, my inclination is to run
just the two hots to the panel and to put a grounding rod close up to
the garage and run a local ground to it.
I see no reason to run a neutral line from the panel (the machines are
all 3 phase).

I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?

What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? ($ signs get much bigger with the wire gage/diameter :-)

Anybody near San Jose, CA have a spool of #4 or larger gage for
cheap? :-)

Thanks in advance!


Put the converter right near the entrance panel so the highest
current only has to run the short distance. Then run smaller
wire to the remote 3 phase loads. Requires an additional lead
but the lower current req. should work out a lot cheaper.
Now as to "remotely developed grounds" This was legal when
we did a bunch of "cabins in the woods" supplied from a main
lodge back quite a few years ago (I havent checked the code
since). We ran the power with two direct burrial wires and
installed a standard grounding rod at each cabin. This was all
code compliant (at that time).
...lew...

[email protected] February 27th 08 10:01 PM

Rotary phase converter: local ground or all the way to the panel?
 
In alt.engineering.electrical rpseguin wrote:

| I'm just renting the house, which, by the way, doesn't have any
| grounded outlets other than a couple of GFIs in the bathrooms.
| The landlord did put 3 prong grounded receptacles in, even though
| there's no ground wires in any of them.

They don't make very many 2-prong ungrounded GFCI receptacles, even
though such things would work and can even do a self-test without a
ground wire.

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / |
|------------------------------------/-------------------------------------|

Chris Lewis February 27th 08 10:02 PM

Rotary phase converter: local ground or all the way to the panel?
 
According to rpseguin :

I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?


Yes, for the reasons expressed by others.

What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? ($ signs get much bigger with the wire gage/diameter :-)


Remember that there are losses in the RPC. A 10HP spindle actually
loaded to 10HP (as opposed to an unloaded 10HP motor) is going to
present something more like 12-13HP on the RPC. So, you're going to
have to factor in 20-30% losses.

Secondly, yeah, wire is expensive. You may wish to consider
using aluminum instead. Done correctly (to-code connectors and
conductive grease for the application), it's just as safe, to-code,
and a lot cheaper.

When I installed the 100A subpanel to my detached garage (100'
of burial), I saved something near $300 by using aluminum instead
of copper, and the inspector was perfectly happy with it - despite
catching the electrician forgetting the grease on the subpanel end... ;-).
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.

Chris Lewis February 27th 08 10:09 PM

Rotary phase converter: local ground or all the way to the panel?
 
According to :
In alt.engineering.electrical rpseguin wrote:

| I'm just renting the house, which, by the way, doesn't have any
| grounded outlets other than a couple of GFIs in the bathrooms.
| The landlord did put 3 prong grounded receptacles in, even though
| there's no ground wires in any of them.

They don't make very many 2-prong ungrounded GFCI receptacles, even
though such things would work and can even do a self-test without a
ground wire.


True. But to clarify: three prong GFCI receptacles that aren't grounded
are legal. Ungrounded three prong outlets _downstream_ of a GFCI are
also legal (as a retrofit), as long as you use the stickers saying
"ungrounded outlet" on them.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.

[email protected] February 27th 08 10:10 PM

Rotary phase converter: local ground or all the way to the panel?
 
Folks:

I gotta say, when you start tossing 20HP rotary convertors and 10 hp
motors
into the pot, economy starts to shed its meaning. Best to do the job
right.
If a 10 hp motor can't pay for its own infrastructure it might as well
go to
pasture. I'd say this even goes if the motor is for recreational use
-- fun
does have value, but fun can turn bad if you cut corners. Don't skimp
on
your hot sticks when turning on your Tesla coil.

But, man, ten horses...some people have big fun, I guess.

A P



Ken Sterling February 28th 08 03:23 AM

Rotary phase converter: local ground or all the way to the panel?
 
Ok.
Thanks for everybody's help in the earlier thread.
The 20HP rotary phase converter is working, but I now need to place it
in the garage, about 70+ feet wiring run distance from the main
breaker panel.

Given the cost of copper wire these days, my inclination is to run
just the two hots to the panel and to put a grounding rod close up to
the garage and run a local ground to it.
I see no reason to run a neutral line from the panel (the machines are
all 3 phase).

I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?

What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? ($ signs get much bigger with the wire gage/diameter :-)

Anybody near San Jose, CA have a spool of #4 or larger gage for
cheap? :-)

Thanks in advance!

Don't know your actual installation plan, but you may be able to pick
up a coil of #4 AL triplex from the local power company - some of it
gets scrapped, either from teardown, or a leftover chunk off of a
reel.
Ken.


Jeffrey Lebowski[_2_] February 28th 08 03:31 AM

Rotary phase converter: local ground or all the way to the panel?
 

Ken Sterling (Ken Sterling) wrote in message
...
Ok.
Thanks for everybody's help in the earlier thread.
The 20HP rotary phase converter is working, but I now need to place it
in the garage, about 70+ feet wiring run distance from the main
breaker panel.

Given the cost of copper wire these days, my inclination is to run
just the two hots to the panel and to put a grounding rod close up to
the garage and run a local ground to it.
I see no reason to run a neutral line from the panel (the machines are
all 3 phase).

I know that I could run a ground line to the panel AND run a local
grounding rod, but is it a bad idea to just do a local ground?

What gage wire for a 20HP RPC, but the main/biggest load/machine will
be a 10HP spindle and a couple of 2HP machines, never all at the same
time? ($ signs get much bigger with the wire gage/diameter :-)

Anybody near San Jose, CA have a spool of #4 or larger gage for
cheap? :-)

Thanks in advance!

Don't know your actual installation plan, but you may be able to pick
up a coil of #4 AL triplex from the local power company - some of it
gets scrapped, either from teardown, or a leftover chunk off of a
reel.
Ken.


Shhh but in a pinch I've used a "strand"--twisted together from 3 individual
pieces of #12 or 14 copper.

--



rpseguin February 28th 08 09:59 AM

Rotary phase converter: local ground or all the way to the panel?
 
Shhh but in a pinch I've used a "strand"--twisted together from 3 individual
pieces of #12 or 14 copper.



:-)
I get the message. I won't cheap out. My credit card is feeling the
strain though.

Still looking around for some #2 or bigger. I've got a lead on some
#4 wire.

My plan, after all the advice is to put a single phase 100A subpanel
in the garage.
That subpanel will have a breaker for the RPC.


Main
Panel
|
| #2 wire, 70+ feet run
|
1ph
Sub-panel
|
| 60A 2 pole breaker, #2 wire, 10 foot max run
|
RPC
|
| #2 wire, 10 foot max run
|
3ph
Panel
(3ph/pole breakers for machines)


Ned Simmons February 28th 08 02:56 PM

Rotary phase converter: local ground or all the way to the panel?
 
On Thu, 28 Feb 2008 00:59:59 -0800 (PST), rpseguin
wrote:

Shhh but in a pinch I've used a "strand"--twisted together from 3 individual
pieces of #12 or 14 copper.



:-)
I get the message. I won't cheap out. My credit card is feeling the
strain though.

Still looking around for some #2 or bigger. I've got a lead on some
#4 wire.


As has been mentioned, you don't need a full size ground. You should
check the code, but my recollection is that a #10 is a suitable
grounding conductor for a 60A circuit.

--
Ned Simmons

Gary H. Lucas February 29th 08 03:07 AM

Rotary phase converter: local ground or all the way to the panel?
 

"rpseguin" wrote in message
...
Shhh but in a pinch I've used a "strand"--twisted together from 3
individual
pieces of #12 or 14 copper.



:-)
I get the message. I won't cheap out. My credit card is feeling the
strain though.

Still looking around for some #2 or bigger. I've got a lead on some
#4 wire.

My plan, after all the advice is to put a single phase 100A subpanel
in the garage.
That subpanel will have a breaker for the RPC.


Main
Panel
|
| #2 wire, 70+ feet run
|
1ph
Sub-panel
|
| 60A 2 pole breaker, #2 wire, 10 foot max run
|
RPC
|
| #2 wire, 10 foot max run
|
3ph
Panel
(3ph/pole breakers for machines)


If you don't need to go underground buy aluminum mud cable, this will easily
be the cheapest solution. Aluminum got a bad name because they tried to use
it in small sizes in residential, with the wrong devices, along with labor
that was clueless about proper techniques. We made a lot of money fixing
jobs done wrong in aluminum, and I have never seen a properly done aluminum
job fail.

Gary H. Lucas



Stuart[_2_] February 29th 08 11:52 AM

Rotary phase converter: local ground or all the way to the panel?
 
In article TNJxj.9292$Dz4.6687@trnddc01,
Gary H. Lucas wrote:
Aluminum got a bad name because they tried to use it in small sizes in
residential, with the wrong devices, along with labor that was clueless
about proper techniques. We made a lot of money fixing jobs done wrong
in aluminum, and I have never seen a properly done aluminum job fail.


I seem to remember using some sort of yellow paste where it was joined to
other metals to prevent corrosion - Unial?

--
Stuart Winsor

From is valid but subject to change without notice if it gets spammed.

For Barn dances and folk evenings in the Coventry and Warwickshire area
See: http://www.barndance.org.uk

rpseguin February 29th 08 09:38 PM

Rotary phase converter: local ground or all the way to the panel?
 
| | I'm just renting the house, which, by the way, doesn't have any
| | grounded outlets other than a couple of GFIs in the bathrooms.
| | The landlord did put 3 prong grounded receptacles in, even though
| | there's no ground wires in any of them.
|
| They don't make very many 2-prong ungrounded GFCI receptacles, even
| though such things would work and can even do a self-test without a
| ground wire.
|
| True. But to clarify: three prong GFCI receptacles that aren't grounded
| are legal. Ungrounded three prong outlets _downstream_ of a GFCI are
| also legal (as a retrofit), as long as you use the stickers saying
| "ungrounded outlet" on them.

How about one of those grounded plug adapters ... the kind where you have
3 holes on one end to plug in a grounded plug, and only 2 prongs on the
other end to plug into a legacy 2-hole no-ground outlet ... that integrates
GFCI protection as part of the adapter? I've seen GFCI cord sets, but only
with a grounded plug. How about with an ungrounded plug?



The GFCIs look grounded to my tester. I haven't bothered to open
them up and look if there is a ground wire in there.
What I was trying to say is that all of the "normal" (non-GFCI) 3
prong outlets are just hot and neutral with no ground wire in there.
Landlord did the cheap thing, although I don't know of any easy and
inexpensive way to retrofit a ground in to a lot of outlets (say 20+).

As for my sub-panel and 3 phase panel things, I've just ordered a 500'
spool of #1 aluminum wire. It is _WAY_ less expensive than copper. I
will be certain to read up and make certain that I bond everything
correctly, use anti-corrosion goo and make certain all connections
are torqued down properly. The RPC and all of the machine loads will
be made using some copper THHN that I already have.

I've acquired a Cutler Hammer 3BR1224L125 125 amp 3 phase circuit
breaker load center panel and now I need to find some CH BR3xx plug/
stab-in breakers. 3 pole breakers are pricey new!
Anybody have some Cutler Hammer compatible breakers like these:
BR360
BR350
BR340
BR330
BR320
BR315
BR310

Thanks!

rpseguin February 29th 08 09:39 PM

Rotary phase converter: local ground or all the way to the panel?
 
On Feb 29, 2:52 am, Stuart wrote:
In article TNJxj.9292$Dz4.6687@trnddc01,
Gary H. Lucas wrote:

Aluminum got a bad name because they tried to use it in small sizes in
residential, with the wrong devices, along with labor that was clueless
about proper techniques. We made a lot of money fixing jobs done wrong
in aluminum, and I have never seen a properly done aluminum job fail.


I seem to remember using some sort of yellow paste where it was joined to
other metals to prevent corrosion - Unial?



As for my sub-panel and 3 phase panel things, I've just ordered a 500'
spool of #1 aluminum wire. It is _WAY_ less expensive than copper. I
will be certain to read up and make certain that I bond everything
correctly, use anti-corrosion goo and make certain all connections
are torqued down properly. The RPC and all of the machine loads will
be made using some copper THHN that I already have.

I've acquired a Cutler Hammer 3BR1224L125 125 amp 3 phase circuit
breaker load center panel and now I need to find some CH BR3xx plug/
stab-in breakers. 3 pole breakers are pricey new!
Anybody have some Cutler Hammer compatible breakers like these:
BR360
BR350
BR340
BR330
BR320
BR315
BR310

Thanks!

PrecisionMachinisT March 1st 08 02:49 AM

Rotary phase converter: local ground or all the way to the panel?
 

"rpseguin" wrote in message
...

snip

stab-in breakers. 3 pole breakers are pricey new!
Anybody have some Cutler Hammer compatible breakers like these:
BR360
BR350
BR340
BR330
BR320
BR315
BR310


Suggest try Ebay...

--





Gary H. Lucas March 1st 08 03:48 AM

Rotary phase converter: local ground or all the way to the panel?
 

"rpseguin" wrote in message
...
On Feb 29, 2:52 am, Stuart wrote:
In article TNJxj.9292$Dz4.6687@trnddc01,
Gary H. Lucas wrote:

Aluminum got a bad name because they tried to use it in small sizes in
residential, with the wrong devices, along with labor that was clueless
about proper techniques. We made a lot of money fixing jobs done wrong
in aluminum, and I have never seen a properly done aluminum job fail.


I seem to remember using some sort of yellow paste where it was joined to
other metals to prevent corrosion - Unial?



As for my sub-panel and 3 phase panel things, I've just ordered a 500'
spool of #1 aluminum wire. It is _WAY_ less expensive than copper. I
will be certain to read up and make certain that I bond everything
correctly, use anti-corrosion goo and make certain all connections
are torqued down properly. The RPC and all of the machine loads will
be made using some copper THHN that I already have.

I've acquired a Cutler Hammer 3BR1224L125 125 amp 3 phase circuit
breaker load center panel and now I need to find some CH BR3xx plug/
stab-in breakers. 3 pole breakers are pricey new!
Anybody have some Cutler Hammer compatible breakers like these:
BR360
BR350
BR340
BR330
BR320
BR315
BR310

Thanks!


Here's how to do the aluminum connections. First, do NOT nick the strands
when stripping the insulation! The nicked strands break right off. Second,
wire brush the bare wire with a stainless wirebrush. Aluminum oxide, unlike
copper oxide is one of the best insulators known. Third, use an antioxidant
compound, Penetrox is the brand we used to use. It is conductive, so don't
get it on the insulation. Fourth, tighten the setscrews firmly. Fifth, and
VERY important, tighten the setscrews again the next day. Aluminum creeps,
and they will often be loose by the next day. Pretty stable after that, but
checking once a year or so is just smart. Finally, aluminum connections
come loose if they are overloaded, because the aluminum expands a lot and
squeezes out like toothpaste. So don't be a cheap ass and overload it, use
the right size.

Gary H. Lucas



Chris Lewis March 3rd 08 07:09 PM

Rotary phase converter: local ground or all the way to the panel?
 
According to :
In alt.engineering.electrical Chris Lewis wrote:
| According to :
| In alt.engineering.electrical rpseguin wrote:
|
| | I'm just renting the house, which, by the way, doesn't have any
| | grounded outlets other than a couple of GFIs in the bathrooms.
| | The landlord did put 3 prong grounded receptacles in, even though
| | there's no ground wires in any of them.
|
| They don't make very many 2-prong ungrounded GFCI receptacles, even
| though such things would work and can even do a self-test without a
| ground wire.
|
| True. But to clarify: three prong GFCI receptacles that aren't grounded
| are legal. Ungrounded three prong outlets _downstream_ of a GFCI are
| also legal (as a retrofit), as long as you use the stickers saying
| "ungrounded outlet" on them.


How about one of those grounded plug adapters ... the kind where you have
3 holes on one end to plug in a grounded plug, and only 2 prongs on the
other end to plug into a legacy 2-hole no-ground outlet ... that integrates
GFCI protection as part of the adapter? I've seen GFCI cord sets, but only
with a grounded plug. How about with an ungrounded plug?


I'm not absolutely certain of the full nuances[+] of "plug connected device"
w.r.t. CEC or NEC, but strictly speaking I don't think NEC or CEC
applies in this case.

_However_, UL and CSA do. In particular, 2 two pin to 3 socket
adapter (without GFCI) will not pass CSA, and is illegal to offer
for sale in Canada. I do not believe such a device will pass UL
either, but UL doesn't have power-of-law as CSA (or legislatively
equivalent) does in Canada.

Conversely, if it has non-fraudulent UL or CSA markings on it,
it will be legal unless overruled by local ordinance.

[+] I'm meaning edge-cases here. 2-3 plug adapters that simply
make the third pin connect via pigtail to the outlet cover screw
are illegal and covered by both NEC and CEC I believe. As the ground
wire is screwed on, I think they're considered "permanent wiring".
Or something. I dunno for sure. They're certainly illegal in Canada
because they won't be granted CSA approval.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.


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