20 Apr
2001
20 Apr
'01
7:48 a.m.
Date: Fri, 20 Apr 2001 15:31:36 +0000
From: Gunther Schadow <gunther(a)aurora.regenstrief.org>
To: Sridhar Ayengar <sridhar(a)ikickass.org>
CC: port-vax(a)netbsd.org, classiccmp(a)classiccmp.org
Subject: VAX 6000 3-phase conversion (was: Re: Three Phase)
Let's look at the plan again:
____________________ +300V
| | |
-__ -__ -__ thyristors
^ ^ ^
| | |
L1 ------* | |
L2 -----------* |
L3 ----------------*
| | |
- - - diodes
^ ^ ^
| | |
--------------------- Return
---- FOR 220 V SINGLE PHASE -----------------------------------------
With a 220 V single phase power supply (P and N coming out of your
receptacle,) as in Europe, Australia, India (?), etc. all you would
need to do is, e.g., put P on L1 and N on L2. That gives 220 V ~
input and if this sqrt(2) rule is correct (which I'm still a little
confused about) you get 220V * 1.414 = 311.8 DC, i.e., just right.
---- FOR US 2 x 110 V TWO PHASE -------------------------------------
For the US I am thinking that may be the 2 phase 220 V dryer hookup
is the best way to go. Not only is this line at a convenient location
where you can store a big cabinet like this one, it is also well
dimensioned to sustain a VAX or (and may be AND) your dryer. Otherwise,
just dry your clothes on a line. But do not mistake the VAX's blower
with your front-loading washer :-).
Seriously, the two phases here, as I understand it, are:
------- P1
------- N
------- P2
with U peek = 110 V and the phases of P1 and P2 being displaced by
180 degree. So, if you measure U between P1 and P2 you get 2 x 110 V
= 220 V. So, I would then connect it like this:
This is really 220v single phase. And the 110 refers to the nominal
RMS voltage. Nearer to 120 these days. The peak voltage is, of course
about 1.4x the RMS.
____________________ +300V
| | |
-__ -__ -__ thyristors
^ ^ ^
| | |
P1 -L1 -----* | |
(N)-L2 ----------* |
P2 -L3 ---------------*
| | |
- - - diodes
^ ^ ^
| | |
--------------------- Return
I am not sure whether to use N on L2 or leave N open (again, I
notice how much I forgot about my high school physics.) This actally
bugs me, because I don't know quite where to connect to the ground
potential and how to deal with the protective ground here.
I would strongly advocate leaving one of the three inputs (L1, L2, L3)
open, and connect the other two to P1 and P2. This makes a full-wave
controlled bridge rectifier across the "220" line. The peak voltage
(hence the no-load DC output) would be 220 sqrt(2), about 340V.
The DC output is floating with respect to protective ground, but
will be isolated by the transformer in the switching supply that
runs from the nominal 300V.
carl (amateur electrician)
--
carl lowenstein marine physical lab u.c. san diego
{decvax|ucbvax} !ucsd!mpl!cdl cdl(a)mpl.ucsd.edu
clowenstein(a)ucsd.edu
20 Apr
20 Apr
10:51 a.m.
Let's see. As I understand it, I would just have to hook up one phase and
everything would be fine. Anyone have the pinouts for the dryer power
connector and the end of the cable from the VAX PS?
Peace... Sridhar
On Fri, 20 Apr 2001, Carl Lowenstein wrote:
Date: Fri, 20
Apr 2001 15:31:36 +0000
From: Gunther Schadow <gunther(a)aurora.regenstrief.org>
To: Sridhar Ayengar <sridhar(a)ikickass.org>
CC: port-vax(a)netbsd.org, classiccmp(a)classiccmp.org
Subject: VAX 6000 3-phase conversion (was: Re: Three Phase)
Let's look at the plan again:
____________________ +300V
| | |
-__ -__ -__ thyristors
^ ^ ^
| | |
L1 ------* | |
L2 -----------* |
L3 ----------------*
| | |
- - - diodes
^ ^ ^
| | |
--------------------- Return
---- FOR 220 V SINGLE PHASE -----------------------------------------
With a 220 V single phase power supply (P and N coming out of your
receptacle,) as in Europe, Australia, India (?), etc. all you would
need to do is, e.g., put P on L1 and N on L2. That gives 220 V ~
input and if this sqrt(2) rule is correct (which I'm still a little
confused about) you get 220V * 1.414 = 311.8 DC, i.e., just right.
---- FOR US 2 x 110 V TWO PHASE -------------------------------------
For the US I am thinking that may be the 2 phase 220 V dryer hookup
is the best way to go. Not only is this line at a convenient location
where you can store a big cabinet like this one, it is also well
dimensioned to sustain a VAX or (and may be AND) your dryer. Otherwise,
just dry your clothes on a line. But do not mistake the VAX's blower
with your front-loading washer :-).
Seriously, the two phases here, as I understand it, are:
------- P1
------- N
------- P2
with U peek = 110 V and the phases of P1 and P2 being displaced by
180 degree. So, if you measure U between P1 and P2 you get 2 x 110 V
= 220 V. So, I would then connect it like this:
This is really 220v single phase. And the 110 refers to the nominal
RMS voltage. Nearer to 120 these days. The peak voltage is, of course
about 1.4x the RMS.
____________________ +300V
| | |
-__ -__ -__ thyristors
^ ^ ^
| | |
P1 -L1 -----* | |
(N)-L2 ----------* |
P2 -L3 ---------------*
| | |
- - - diodes
^ ^ ^
| | |
--------------------- Return
I am not sure whether to use N on L2 or leave N open (again, I
notice how much I forgot about my high school physics.) This actally
bugs me, because I don't know quite where to connect to the ground
potential and how to deal with the protective ground here.
I would strongly advocate leaving one of the three inputs (L1, L2, L3)
open, and connect the other two to P1 and P2. This makes a full-wave
controlled bridge rectifier across the "220" line. The peak voltage
(hence the no-load DC output) would be 220 sqrt(2), about 340V.
The DC output is floating with respect to protective ground, but
will be isolated by the transformer in the switching supply that
runs from the nominal 300V.
carl (amateur electrician)
--
carl lowenstein marine physical lab u.c. san diego
{decvax|ucbvax} !ucsd!mpl!cdl cdl(a)mpl.ucsd.edu
clowenstein(a)ucsd.edu
6:39 p.m.
Hi again,
Thanks for those who commented on this power issue.
This evening, I have given it a shot using my spare parts. I took
the box that has the thick 3-phase cable. I opened the rear of that box
and removed this cable in order to attach one that I can actually
plug in somewhere. This is what I saw:
+----------------------------------------------------+
| -------------------- |
| +--------------------+ / GND * \ |
| | | / \ |
| | | |Bl* *Br| |
| | | | Bk* *Bk | |
| | | +----------------------+ |
| | | |
| | | +------------------------+ |
| | | | | |
| | | | | |
| +--------------------+ +------------------------+ |
| |
+-----------------------------------------------------+
After opening the cover, the cable is hooked to 5 screws. There is
one yellow/green protective ground wire, even laveled GND. Then
there is a blue (Bl) wire, two black (Bk) wires and one brown (Br)
wire. I probably don't understand this color coding and I was also
surprized to find four not three wires besides protective ground.
I then hooked this up as follows:
P1 ------------* Bl
* Bk
GND ----------------* GND
* Bk
P2 ------------*Br
that is I connected the protective ground with my protective ground
wire, and P1 to where the blue line used to be and P2 where the Brown
line connected. I left the ex-black connectors open.
Closed the cover and plugged it in. This cover has three control
lights labeled PL1, PL2, and PL3. I noticed that only PL1 was lit.
Then I pushed this T shaped main switch in to engage and using
a potentiometer I checked for AC and DC potentials at about every
receptacle on this box. What I found was disappointing.
I did not find any DC potential anywhere. (I may not have tried
every combination though.) Is it possible that this box does not
have any bridge rectifier in it so all I can expect is AC here
and there? Is there any documentation around what all these many
receptacles are for and how the pins are connected?
Finally, I recognized three standard computer receptacles, you
know, the ones we used to have on PC's power units and where
one would plug in the monitor power. These receptacles look as
follows:
3
+------+
/ || \
| |
| || || |
+----------+
1 2
I think what one would expect is that 3 is protective GND, and
1 is Null (N) and 2 is 110 V phase (P) (or 1 P and 2 N, doesn't
matter.) However, that was not what I found. I found that two
of the receptacles has 110 V between 2 and 3 (but not 1 and 2),
and the third receptacle had 110 V between each 1 and 3 and 2
and 3 and 220 V between 1 and 2.
So, something is screwy. I stopped fiddling for tonight. May
be you have some suggestions about what I should do. My plan
is to try connecting things differently, using the two Black
lines instead of the Brown line ... but I'm fairly clueless.
Also, I am not sure I hooked up my circuit breaker box in my
basement correctly. I have one spare 220 V 60 A 2-phase (dryer
hookup) line in my basement. I attached a 2-phase circuit
breaker box as follows:
B C W R
L O H E
A P I D
C P T |
K P E |
| E | |
| R | |
| | | +-------+
| | | |
+---+ | +--+ |
| | | |
| o*oooo*ooo |
| |
=*============== |
|
|
===================*
The 60 A uplink line comes with four wires, a black, a red, a white and
a blank copper line. I tested that black is P1, red is P2, white is N
and the copper line's got to be protective GND. As you can see, for
lack of any other connector facility in the breaker box I have connected
the white line (N) with the protective GND line. Should I have done this
differently, like leave the N line open?
However, this shouldn't have an effect on hooking up the VAX, or should
it? Would I not need to connect some N wire so that those receptacles
are powered correctly?
any thoughts appreciated,
-Gunther
21 Apr
21 Apr
2:27 a.m.
On Sat, 21 Apr 2001, Gunther Schadow wrote:
Hi again,
Thanks for those who commented on this power issue.
This evening, I have given it a shot using my spare parts. I took
the box that has the thick 3-phase cable. I opened the rear of that box
and removed this cable in order to attach one that I can actually
plug in somewhere. This is what I saw:
Last night, I open the lower power-supply box on my 6310, the one with the
power cable going into it, and the tee-handle power switch on the side,
(H405-E rev F07, FWIW). From what I could see, the three-phase power
enters via the cable assembly (DEC part number 17-01806-01) and gos
directly into a large, sealed, power filter. From there, it goes to the
main disconnect switch operated by the tee-handle, them thru a contactor
(three pole relay), then exiting via the round 19-position connector. In
short, it's still three phase when it comes out of this box. Further
complications exist; the various power recpticles on the rear and front
are tapped off of different phases inside, presumably in an attempt to
balance the draw on the three phases. Also, there is what appears to be a
small low-voltage supply inside it, as well as another small circuit board
that I didn't examine very closely.
Since the power is switched thru a contactor, there must be controller of
some sort that manages the startup of the VAX. I'll go out on a limb and
say it is in the `Power & Logic Box' (H-7206A). ;)
BINGO! Folks, we may have a winner in the power & logic box. I'll give
it a closer look some time today, but it sure looks good from here.
156~229 input voltage, and it has a `300 volt' LED on the front. Also,
there's ehough logic to control a few contactors.
any thoughts appreciated,
-Gunther
Bob
10:18 a.m.
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4:45 a.m.
On 21 Apr, Gunther Schadow wrote:
There is
one yellow/green protective ground wire, even laveled GND. Then
there is a blue (Bl) wire, two black (Bk) wires and one brown (Br)
wire. I probably don't understand this color coding and I was also
surprized to find four not three wires besides protective ground.
[this may apply
only to Germany]
Yellow/green is protective ground, as you sad. Blue is the Null wire.
Brown and the two black wires are the three phases. The three phases
are generated in a "rotating" system with a phase offset of 120 degrees
to each other. Null is the one common wire to all phases. You can think
of it like a star:
L1
|
|
C
C
C
|
|
*---------------- N
/ \
/ \
C C
C C
C C
/ \
L3 L2
CCC are the three coils in the generator with the 120 degrees offset
(mechanicaly). This results in three AC voltages with a phase offset of
120 degrees (electricaly) . All three voltages have a common point,
Null. So you have voltages form L1 to L2 (L2 to L3 / L3 to L1) and from
N to L1 (N to L2 / N to L3). The voltage N to L1 is (in Germany) 230V
and the Voltage L1 to L2 is 400V. This is a factor of sqrt( 3). This
factor is related to the 120 degrees offset. This voltages are RMS
(Root Mean Squere, also called "effective value"). This RMS is
calculated using an integral... It means that a AC voltage of 230V
produces the same heat in a resistor as a 230V DC voltage. The peak
voltage of 230V AC is 230V * sqrt( 2) = 325V. This is the voltage you
get out of a rectifier.
In the USA, it seems that there is a common wiring like this:
P1
|
|
C
C
C
|
*------ N
|
C
C
C
|
|
P2
This gives a offset of 180 degrees and therefore is the voltage of P1
to P2 twice the voltage of P1 to N (P2 to N)
Protective ground is identical to N. It is only an extra wire to the N
point. This is needed for protection only. (Therefore it is called
protective ground. ;-) )
I hope this gives some light into your darkness. ;-)
I then hooked this up as follows:
P1 ------------* Bl
* Bk
GND ----------------* GND
* Bk
P2 ------------*Br
that is I connected the protective ground with my protective ground
wire, and P1 to where the blue line used to be and P2 where the Brown
line connected. I left the ex-black connectors open.
Closed the cover and plugged it in. This cover has three control
lights labeled PL1, PL2, and PL3. I noticed that only PL1 was lit.
[...]
3
+------+
/ || \
| |
| || || |
+----------+
1 2
I think what one would expect is that 3 is protective GND, and
1 is Null (N) and 2 is 110 V phase (P) (or 1 P and 2 N, doesn't
matter.) However, that was not what I found. I found that two
of the receptacles has 110 V between 2 and 3 (but not 1 and 2),
and the third receptacle had 110 V between each 1 and 3 and 2
and 3 and 220 V between 1 and 2.
Yes. Because you only have connected N (from the
VAX point of view) and
one phase. If my assumtions about US power distributions is correct, you
have to connet P1 not to blue, connect it to one of the black connectors
and connect N to the blue one. Then everything will work, or (perhaps)
it will be toasted. ;-)
BTW: It seems that the three standard computer receptacles are split
around the three phases. So I recommend not to use them. Using them can
result in undefined input voltages of the third rectifier input. Or
disconnect the third input from inside the rectifier. Hmmm? Or connect
the two black to P1, brown to P2, blue to N and ye/gr to PG/GND. This
should give a defined potential to every rectifier input and the
receptacles can be used.
--
tschuess,
Jochen, dreaming of having a VAX like you.
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz
8:22 a.m.
On Sat, 21 Apr 2001 jkunz(a)unixag-kl.fh-kl.de wrote:
Protective ground is identical to N. It is only an
extra wire to the N
point. This is needed for protection only. (Therefore it is called
protective ground. ;-) )
Some clarification is in order...
Protective ground is NOT identical to N, even if they are wired together
at the main breaker panel (as in USA). Neutral is a current carrying
conductor, and because of the resistance in the wire, it may be at some
voltage above ground potential. This is why you NEVER attach the
neutral to the protective ground.
Remember: if there is any possibility of current flow, use the Neutral
wire.
Remember: Always connect the protective ground to the chassis of the
machine.
These voltage are high enough you can destroy valuable antique hardware,
which would be bad. You might get shocked too...
clint
8:44 a.m.
On Sat, 21 Apr 2001, Clint Wolff (VAX collector) wrote:
On Sat, 21 Apr 2001 jkunz(a)unixag-kl.fh-kl.de wrote:
What he said!
Protective ground is identical to N. It is only
an extra wire to the N
point. This is needed for protection only. (Therefore it is called
protective ground. ;-) )
Some clarification is in order...
Protective ground is NOT identical to N, even if they are wired together
at the main breaker panel (as in USA). Neutral is a current carrying
conductor, and because of the resistance in the wire, it may be at some
voltage above ground potential. This is why you NEVER attach the
neutral to the protective ground.
Remember: if there is any possibility of current flow, use the Neutral
wire.
The only purpose of the green (ground) wire is to help the overcurrent
device operate-- it is there to make what might be a small leakage to an
electrically isolated chassis into a large fault to ground.
Remember: Always connect the protective ground to the chassis of the
machine.
Do this, and also connect the other end... (Also, in the US, the old
three-prong dryer & range cords are illegal now. Be sure and use a proper
cordset, that provides an equipment ground)
These voltage are high enough you can destroy valuable antique hardware,
which would be bad. You might get shocked too...
in that order...
clint
Bob
10:04 a.m.
On 21 Apr, Clint Wolff (VAX collector) wrote:
Protective ground is NOT identical to N, even if they
are wired together
at the main breaker panel (as in USA). [...]
I know, it is the same in Germany. The
statement "Protective ground is
identical to N." was only a simplification to illustrate why you
messure the same voltage from a phase to N and from a phase to
protective ground. I wanted to describe how three phase power works,
not how failure protection works and what different kinds of power
network types (TN-C, TN-S, TN-CS, TT, IT or how they are called in the
USA) are possible.
--
tschuess,
Jochen
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz
1:20 p.m.
On Sat, 21 Apr 2001, Gunther Schadow wrote:
This evening, I have given it a shot using my spare
parts. I took
the box that has the thick 3-phase cable. I opened the rear of that box
and removed this cable in order to attach one that I can actually
plug in somewhere. This is what I saw:
+----------------------------------------------------+
| -------------------- |
| +--------------------+ / GND * \ |
| | | / \ |
| | | |Bl* *Br| |
| | | | Bk* *Bk | |
| | | +----------------------+ |
| | | |
| | | +------------------------+ |
| | | | | |
| | | | | |
| +--------------------+ +------------------------+ |
| |
+-----------------------------------------------------+
It might be using the european color coding which is:
Yellow/Green - Protective GND
Blue - 0
Black - P1
Brown - P2
Black or
Black/While - P3
--
cheers,
/Anders
I am Pentium of Borg... -Division is futile!
**************************************************************************
* Anders Hogrelius Phone : +46 21 381860
* Tessingatan 12 E-mail: anders(a)hogrelius.nu
* SE-72216 Vasteras Web: http://www.hogrelius.nu/~ahs/
* SWEDEN
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days inactive
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9 comments
8 participants
participants (8)
-
ahs＠hogrelius.nu -
ard＠p850ug1.demon.co.uk -
cdl＠mpl.ucsd.edu -
gunther＠aurora.regenstrief.org -
jkunz＠unixag-kl.fh-kl.de -
rschaefe＠gcfn.org -
vance＠ikickass.org -
vaxman＠qwest.net