[PRCo] Re: Repeat...

[Boris Cefer]

It is only an informative material to give the basic idea how a PCC type car 
works and details are not important, but if anyone wants to know:

Tatra T2, four TE022 motors, power pedal to the floor (5th point of 
acceleration) theoretically 520 Amps, coasting, dynamic brake (full service 
rate) 380 Amps theoretically. There was no way to record the speed but it 
will be possible some time in the future! Right now I can say that this 
record is 17 seconds long.

I am pretty sure a similar drawing made from oscilloscope measurements of 
1711 would be even more interesting, particularly the phase where field 
shunts come in, because the shunted field on PRCo 1700s (W) was only 33% (in 
our case it is "theoretically" 55%) and the peak values would be higher. 
That's why the 1600s and 1700s had overspeed relays.

B

----- Original Message ----- 
From: "Schneider Fred" <fwschneider at comcast.net>
To: <pittsburgh-railways at dementia.org>
Sent: Thursday, July 30, 2009 9:11 PM
Subject: [PRCo] Re: Repeat...


Boris:
Do you have any idea what car?   What motors?   What percent of
possible accelerating relay spring tension was applied (i.e., how
much pedal was used)

Do we know know what speeds can be applied to the corresponding
points on the amperage curves?

Also was he just touching the brake pedal or is it full dynamic brake?

In answer to my original problem .... I see that if you just position
the mouse anywhere on the drawing and click again, you get full
resolution.   No problem.

So now I can interpret the drawing ... there is a brief amperage
spike up to about 630 amps when the car is accelerating and all four
field shunt coils are connected.   If you are running a system like
Chicago Transit Authority with almost 150 cars on Wentworth Avenue or
State Street or Broadway or Clark St., you can potentially be drawing
some real amps from the substations compared to what you used before
the PCCs were installed even though you may now have fewer cars.

Now I need to find someone locally to make a large print of it to put
into my PCC car data file that is being moved to PTM.

Fred Schneider

Blind carbons to Bruce Wells and Bernie Orient.