Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

On Jan 22, 8:55*pm, Bob Villa wrote:
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

I mark them before I take them off so that I don't mix them up.

I know, it's a novel approach. What can I say...I'm a rebel.

Bob Villa wrote:
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

Put a jumper from one line at a time to ground at the source of the
circuit. Take a continuity test to ground where the wires end. Power
off, naturally, and locked out.

On 1/22/2011 17:55, Bob Villa wrote:
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?

If the motor spins in the wrong direction, swap the leads on phases 2
and 3. Otherwise, phasing isn't critical or you need to ask a more
authoritative source than Usenet.

"Bob Villa" wrote in message
...
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.


If your connections are 3 phase, it shouldn't matter, except for direction
on motors. If the motor spins the wrong way, transpose any two wires. If you
want to connect to something single phase on a high leg delta, you need to
determine which is the wild leg, which you can do with a volt meter.

On Jan 22, 8:55*pm, Bob Villa wrote:
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

HAHAHA:/ I DONT., I LET A TESTER DO IT FOR ME.
IN ANY EVENT SEE HOW THEY ARE ATTACHED AT THE SERVICE ENTRANCE OR
SOURCE AND
INSTALL THEM ACCORDINGLY AT THE DISTRIBUTION PANEL OR END.

I AM OBLIGATED BY THE RULES OF THE GHOST CONVENTION OF DEAD WANNABE
ELECTRICIANS THAT YOU SHOULD MESS WITH THAT.
GET A QUALIFIED PERSON FOR THOSE JOBS:/

PAT ECUM

On 1/22/2011 9:41 PM, RBM wrote:
"Bob wrote in message
...
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.


If your connections are 3 phase, it shouldn't matter, except for direction
on motors. If the motor spins the wrong way, transpose any two wires. If you
want to connect to something single phase on a high leg delta, you need to
determine which is the wild leg, which you can do with a volt meter.



When I install 3 phase refrigeration or HVAC equipment, I also install
or order the factory option of a 3 phase protection module which shuts
down the control voltage if there is any problem with the power. The
cheap simple unit doesn't care about which direction a motor is turning
in relation to incoming power but there is a more elaborate unit that I
install on high end gear that will not operate if the 3 phase is not
exactly L1 L2 L3 as seen on an oscilloscope.

TDD

On Jan 23, 1:55*am, Bob Villa wrote:
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

If you are talking about a motor, the only aspect to consider is the
motor direction. If the motor is running in the wrong direction,
reverse any two of the three phase wires.
The problem arises if mechanical damage can be caused by running the
motor the wrong way. in which case you will need to mechanically
disconnect the motor and run it to establish if it's running in the
correct direction.

If it's heating you're talking about, it doesn't matter

The Daring Dufas wrote:

When I install 3 phase refrigeration or HVAC equipment, I also install
or order the factory option of a 3 phase protection module which shuts
down the control voltage if there is any problem with the power. The
cheap simple unit doesn't care about which direction a motor is turning
in relation to incoming power but there is a more elaborate unit that I
install on high end gear that will not operate if the 3 phase is not
exactly L1 L2 L3 as seen on an oscilloscope.

TDD

Do you ever use anything like this Amprobe phase tester?
http://tinyurl.com/4ukhq4b

On Jan 22, 11:07*pm, The Ghost in The Machine
wrote:
On Jan 22, 8:55*pm, Bob Villa wrote:

Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.



I AM OBLIGATED BY THE RULES OF THE GHOST CONVENTION OF DEAD WANNABE
ELECTRICIANS THAT YOU SHOULDn't MESS WITH THAT.
GET A QUALIFIED PERSON FOR THOSE JOBS:/

PAT ECUM

I would think you would want more conventioneers!
"Qualified", as far as OSHA is concerned...I never touch the stuff!

On Jan 22, 9:41*pm, "RBM" wrote:
"Bob Villa" wrote in message

...

Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

If your connections are 3 phase, it shouldn't matter, except for direction
on motors. If the motor spins the wrong way, transpose any two wires. If you
want to connect to something single phase on a high leg delta, you need to
determine which is the wild leg, which you can do with a volt meter.

Thanks for the replies...I thought it might be that simple.

bob_v

"Dean Hoffman" wrote in message
...
The Daring Dufas wrote:

When I install 3 phase refrigeration or HVAC equipment, I also install or
order the factory option of a 3 phase protection module which shuts
down the control voltage if there is any problem with the power. The
cheap simple unit doesn't care about which direction a motor is turning
in relation to incoming power but there is a more elaborate unit that I
install on high end gear that will not operate if the 3 phase is not
exactly L1 L2 L3 as seen on an oscilloscope.

TDD

Do you ever use anything like this Amprobe phase tester?
http://tinyurl.com/4ukhq4b


Years ago we use to have a mechanical phase tester. We were supposed to use
it when connecting 3 phase service equipment. When connecting a 3 phase
motor, it doesn't help to know the phase rotation of the power supply, but
not know the phase rotation of the motor leads. Ultimately, trial and error
is probably the quickest method

On 1/23/2011 7:18 AM, Dean Hoffman wrote:
The Daring Dufas wrote:

When I install 3 phase refrigeration or HVAC equipment, I also install
or order the factory option of a 3 phase protection module which shuts
down the control voltage if there is any problem with the power. The
cheap simple unit doesn't care about which direction a motor is turning
in relation to incoming power but there is a more elaborate unit that I
install on high end gear that will not operate if the 3 phase is not
exactly L1 L2 L3 as seen on an oscilloscope.

TDD

Do you ever use anything like this Amprobe phase tester?
http://tinyurl.com/4ukhq4b

I've had a Sperry rotating disk phase sequence tester for many years. I
believe Ideal bought Sperry out according to this picture.

http://www.drillspot.com/products/77...otation_Tester

http://preview.tinyurl.com/5tuzfey

TDD

On 1/23/2011 7:51 AM, RBM wrote:
"Dean wrote in message
...
The Daring Dufas wrote:

When I install 3 phase refrigeration or HVAC equipment, I also install or
order the factory option of a 3 phase protection module which shuts
down the control voltage if there is any problem with the power. The
cheap simple unit doesn't care about which direction a motor is turning
in relation to incoming power but there is a more elaborate unit that I
install on high end gear that will not operate if the 3 phase is not
exactly L1 L2 L3 as seen on an oscilloscope.

TDD

Do you ever use anything like this Amprobe phase tester?
http://tinyurl.com/4ukhq4b


Years ago we use to have a mechanical phase tester. We were supposed to use
it when connecting 3 phase service equipment. When connecting a 3 phase
motor, it doesn't help to know the phase rotation of the power supply, but
not know the phase rotation of the motor leads. Ultimately, trial and error
is probably the quickest method



I use my phase tester even when the power company crew is there hooking
up the drop. The linemen around here are OK with it and will make sure
the sequence is right before making a permanent connection. Southern
Company Power wires L2 as the high leg in a Wye secondary 3 phase. If
I'm lucky, I can get Delta-Delta then everybody's happy. :-)

TDD

TDD

Bob Villa wrote:
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

If you are particular go to the panel and put a toner on A phase then go
to the wire end with the detector. Same for B phase, last one must be C.
It really doesn't matter except for three phase motors motors.

--
LSMFT

Those who would give up Essential Liberty
to purchase a little Temporary Safety,
deserve neither Liberty nor Safety.

On Sun, 23 Jan 2011 09:09:01 -0600, The Daring Dufas
wrote:

On 1/23/2011 7:51 AM, RBM wrote:
"Dean wrote in message
...
The Daring Dufas wrote:

When I install 3 phase refrigeration or HVAC equipment, I also install or
order the factory option of a 3 phase protection module which shuts
down the control voltage if there is any problem with the power. The
cheap simple unit doesn't care about which direction a motor is turning
in relation to incoming power but there is a more elaborate unit that I
install on high end gear that will not operate if the 3 phase is not
exactly L1 L2 L3 as seen on an oscilloscope.

TDD

Do you ever use anything like this Amprobe phase tester?
http://tinyurl.com/4ukhq4b


Years ago we use to have a mechanical phase tester. We were supposed to use
it when connecting 3 phase service equipment. When connecting a 3 phase
motor, it doesn't help to know the phase rotation of the power supply, but
not know the phase rotation of the motor leads. Ultimately, trial and error
is probably the quickest method



I use my phase tester even when the power company crew is there hooking
up the drop. The linemen around here are OK with it and will make sure
the sequence is right before making a permanent connection. Southern
Company Power wires L2 as the high leg in a Wye secondary 3 phase. If
I'm lucky, I can get Delta-Delta then everybody's happy. :-)

The secondary is a delta if it has a high leg. A wye will have equal
voltage on each leg with respect to the grounded conductor.
--
Mr.E

On Sun, 23 Jan 2011 11:12:11 -0500, LSMFT wrote:

Bob Villa wrote:
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

If you are particular go to the panel and put a toner on A phase then go
to the wire end with the detector. Same for B phase, last one must be C.
It really doesn't matter except for three phase motors motors.

ANd if the panel or the power company is wrong? After the panel it's tough to
screw up the color coding.

Many moons ago (over 35 years) I designed a power phase detector that found
its way into every IBM mainframe of the time. They didn't like the blowers
running backwards, but the phase-controlled regulators really got ****ed with
reversed phase rotation. Before the three-phase contactors kicked in the
service system would sense the phase rotation and lock up with an error if
they were bad. It *did* change at times, particularly after major power
changes and bad storms. Relying on the installers to test the rotation didn't
work.

On 1/23/2011 10:54 AM, lid wrote:
On Sun, 23 Jan 2011 09:09:01 -0600, The Daring Dufas
wrote:

On 1/23/2011 7:51 AM, RBM wrote:
"Dean wrote in message
...
The Daring Dufas wrote:

When I install 3 phase refrigeration or HVAC equipment, I also install or
order the factory option of a 3 phase protection module which shuts
down the control voltage if there is any problem with the power. The
cheap simple unit doesn't care about which direction a motor is turning
in relation to incoming power but there is a more elaborate unit that I
install on high end gear that will not operate if the 3 phase is not
exactly L1 L2 L3 as seen on an oscilloscope.

TDD

Do you ever use anything like this Amprobe phase tester?
http://tinyurl.com/4ukhq4b


Years ago we use to have a mechanical phase tester. We were supposed to use
it when connecting 3 phase service equipment. When connecting a 3 phase
motor, it doesn't help to know the phase rotation of the power supply, but
not know the phase rotation of the motor leads. Ultimately, trial and error
is probably the quickest method



I use my phase tester even when the power company crew is there hooking
up the drop. The linemen around here are OK with it and will make sure
the sequence is right before making a permanent connection. Southern
Company Power wires L2 as the high leg in a Wye secondary 3 phase. If
I'm lucky, I can get Delta-Delta then everybody's happy. :-)

The secondary is a delta if it has a high leg. A wye will have equal
voltage on each leg with respect to the grounded conductor.

DOAH! I stand corrected. I should have said center tapped delta has the
high leg. I was reading my diagrams wrong and I don't even use
recreational drugs. I got it mixed up. :-)

TDD

On 1/23/2011 11:08 AM, zzzzzzzzzz wrote:
On Sun, 23 Jan 2011 11:12:11 -0500, wrote:

Bob Villa wrote:
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

If you are particular go to the panel and put a toner on A phase then go
to the wire end with the detector. Same for B phase, last one must be C.
It really doesn't matter except for three phase motors motors.

ANd if the panel or the power company is wrong? After the panel it's tough to
screw up the color coding.

Many moons ago (over 35 years) I designed a power phase detector that found
its way into every IBM mainframe of the time. They didn't like the blowers
running backwards, but the phase-controlled regulators really got ****ed with
reversed phase rotation. Before the three-phase contactors kicked in the
service system would sense the phase rotation and lock up with an error if
they were bad. It *did* change at times, particularly after major power
changes and bad storms. Relying on the installers to test the rotation didn't
work.

Didn't some of those mainframes use 400hz AC power like aircraft so the
power transformers could be smaller/lighter?

TDD

On Sun, 23 Jan 2011 11:37:16 -0600, The Daring Dufas
wrote:

On 1/23/2011 11:08 AM, zzzzzzzzzz wrote:
On Sun, 23 Jan 2011 11:12:11 -0500, wrote:

Bob Villa wrote:
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

If you are particular go to the panel and put a toner on A phase then go
to the wire end with the detector. Same for B phase, last one must be C.
It really doesn't matter except for three phase motors motors.

ANd if the panel or the power company is wrong? After the panel it's tough to
screw up the color coding.

Many moons ago (over 35 years) I designed a power phase detector that found
its way into every IBM mainframe of the time. They didn't like the blowers
running backwards, but the phase-controlled regulators really got ****ed with
reversed phase rotation. Before the three-phase contactors kicked in the
service system would sense the phase rotation and lock up with an error if
they were bad. It *did* change at times, particularly after major power
changes and bad storms. Relying on the installers to test the rotation didn't
work.

Didn't some of those mainframes use 400hz AC power like aircraft so the
power transformers could be smaller/lighter?

Sure, they used M-G sets to get the 400Hz. The M-G sets were also used as the
power-backup to do checkpointing or switchover to secondary power, on power
failure. IIRC, all of the phase controlled regulators used 400Hz. It's been
a long time, but I believe the blowers were all 50/60Hz (they could take a
brown-out on power change).

On 1/23/2011 11:53 AM, zzzzzzzzzz wrote:
On Sun, 23 Jan 2011 11:37:16 -0600, The Daring Dufas
wrote:

On 1/23/2011 11:08 AM, zzzzzzzzzz wrote:
On Sun, 23 Jan 2011 11:12:11 -0500, wrote:

Bob Villa wrote:
Sometimes I work on equipment with 3-phase (delta). If you mix up the
wires...how do YOU figure out which wire goes where?
Thanks.

If you are particular go to the panel and put a toner on A phase then go
to the wire end with the detector. Same for B phase, last one must be C.
It really doesn't matter except for three phase motors motors.

ANd if the panel or the power company is wrong? After the panel it's tough to
screw up the color coding.

Many moons ago (over 35 years) I designed a power phase detector that found
its way into every IBM mainframe of the time. They didn't like the blowers
running backwards, but the phase-controlled regulators really got ****ed with
reversed phase rotation. Before the three-phase contactors kicked in the
service system would sense the phase rotation and lock up with an error if
they were bad. It *did* change at times, particularly after major power
changes and bad storms. Relying on the installers to test the rotation didn't
work.

Didn't some of those mainframes use 400hz AC power like aircraft so the
power transformers could be smaller/lighter?

Sure, they used M-G sets to get the 400Hz. The M-G sets were also used as the
power-backup to do checkpointing or switchover to secondary power, on power
failure. IIRC, all of the phase controlled regulators used 400Hz. It's been
a long time, but I believe the blowers were all 50/60Hz (they could take a
brown-out on power change).

When I was out at the Kwajalein Missile Range, now The Reagan Test Site,
back in 1987-88, There were computer systems on Roi Namur that
had MG sets with big flywheels for UPS type power. The island power
plant used big old EMD diesel generators putting out 4,161 volts
into the island power grid. I suppose the flywheels could keep things up
until another EMD was started but during a mission, I believe a
backup was kept warmed up anyway. I was working for a contractor who
built the new mission control center that housed a Cray X-MP super
computer (high tech back then) and an atomic clock. I don't think the
Cray used any special power because we only ran conventional 60hz
electrical power and wiring.

TDD