MOTM

> ----- Original Message -----
> From: Tentochi <tentochi2003@...>
> I am not quite sure whether to use the terminal block on the '960 or the
faston terminals.

As I see it, it really makes no difference.  I used the screw terminals only
because I prefer lugs to faston terminations.  Paul has made it with
multiple connections which might tempt one to daisy chain from one 960 to
another.  I avoided that temptation and only used one terminaltion on each
960.

One issues I had with the 960s is tightning of the screws.  The terminal
block itself is not attached to the circuit board other than the solder
connections.  So, I think people like me (remember I torqued a screw out of
the back of a 700 panel once) could damage the connection if not careful
when tightening.  I was sure to hold the terminal block and not the PCB when
putting the final trun on the screw.

> What terminal block (brand and model number would be great!) to use coming
out of my '900.

In my opinion, "Marathon" brand terminal blocks are the best.  They are used
widely in industry for terminations where circuits are critical.  I used the
1600 series blocks.  But, I admit that they are total overkill and at least
4 times what is required.  But, I removed them from retired stuff that gets
tossed out at work.

> For a true star configuration, do I need to bypass the distribution board
on the '900, go out to the terminal block and then run power to each of the
distribution boards from there (including the distribution board on the '900
itself)?  Are people removing the distribution board from the '900
altogether in this scenario?

Todd, I have never had a 900 in my hands.  So, I cannot see exactly what you
mean.  But, if the wire size is large enough, you can create a star
"electrically" while it might not have the exact physical characteristics of
a star.  Just use overkill for the wire size from as close to the power
supply terminals as possible directly to each PCB board.  Then, each module
connects from there.  So, really you don't have a true star to each module.
But, if the wire from the power supply to each PCB is short and large,
electrically, those PCB appear to be right at the supply compared to the
resistance in the MOTM power cables.  I certainly cannot recommend jumping
from one PCB to the next with regular MOTM power cables used as a jumper.

> What types of cable is being used between the PSU and terminal block?
Between the terminal block and the distribution boards.

Is does not matter as long as the wired size is significanly larger than the
MOTM power cable wires.  I use # 12 or # 14 stranded copper.

> Does the type of wire need to change if I drop in a larger power supply?

How large is the question.  I am using a 5 amp supply.  Since the distance
is so short, I am staying with # 12 wire, which has a conservative current
rating of 20 amps.  I did think about jumping the wire from the supply to
the distribution block up to # 10.  But, since the measurement was only
about a foot, I curbed my anal tendency and left in the # 12.

> Someone has mentioned here before recommendations for systems with
multiple power suppliers.  Could someone
please restate them for me?

Wasn't me.  But, I think that is a good question.  Should PS ground be
bonded between supplies?  Certainly AC case ground needs to be tied down on
both.  You can have all kinds of problems if you don't.

> Why does the '960 include both faston headers and 2 terminal blocks?

User choice as I saw it.

Larry (not an engineer)