MU connections ID?

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nyandw
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MU connections ID?

Post by nyandw » Sat Jun 22, 2019 12:09 am

This was labeled an FA1 1973, but... Can folks ID the numbered locations and use? Thanks.
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FA1-MU-connections_1973-numbered.jpg

kro52
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Re: MU connections ID?

Post by kro52 » Sat Jun 22, 2019 7:13 am

Greetings

#1 is the 27 point trainline jumper

#2 650 volt single point trainline jumper-negative

#3 650 volt 4 point trainline jumper-positive

KRO52

nyandw
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Re: MU connections ID?

Post by nyandw » Sun Jun 23, 2019 12:33 am

kro52 wrote:
Sat Jun 22, 2019 7:13 am
#1 is the 27 point trainline jumper
#2 650 volt single point trainline jumper-negative
#3 650 volt 4 point trainline jumper-positive
Thank you. Is the unit an FA1? Might the functions/description of these be defined for reference to non-railroad folks?

kro52
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Re: MU connections ID?

Post by kro52 » Sun Jun 23, 2019 8:18 am

Greetings,

There is not enough picture to tell it is a FA1, suffice to say it is by the LIRR designation a PC6

KRO 52

jhdeasy
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Re: MU connections ID?

Post by jhdeasy » Mon Jun 24, 2019 9:48 am

#1: The 27 point trainline jumper was used to control the locomotive from the cab control / power-pack unit.

#2 and #3: The other two jumpers were for the 650 VDC Head End Power system, a system design unique to LIRR. Does anyone know the size of the four individual conductors in LIRR’s positive power trainline? For comparison, Amtrak uses twelve 4/0 (four ought) conductors in their 480 VAC HEP trainline.

You can see there is a fourth jumper located between #2 and #3. What was the function of that fourth jumper?

ExCon90
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Re: MU connections ID?

Post by ExCon90 » Mon Jun 24, 2019 2:46 pm

On #2 and #3, is there color coding, or different plug design, to prevent accidental attempts to plug negative into positive, or v.v.?

Backshophoss
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Re: MU connections ID?

Post by Backshophoss » Mon Jun 24, 2019 4:18 pm

No color code,the 4 pin was the plus power,the single pin was the neg(ground) return
NO way to mix up the connections
The red color cover plate for the 27 point MU plug seems to be the standard at that time.
The Land of Enchantment is not Flyover country!

ExCon90
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Re: MU connections ID?

Post by ExCon90 » Tue Jun 25, 2019 3:05 pm

Thanks--I figured there had to be something.

nyandw
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Re: MU connections ID?

Post by nyandw » Tue Jun 25, 2019 8:27 pm

Renumbered to add the #4 MU connection for description, sorry I missed it...
Anyone with color shots of this?
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FA1-MU-connections_1973-numbered.jpg

nyandw
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Re: MU connections ID? 4th Jumper

Post by nyandw » Mon Jul 01, 2019 1:34 am

Thanks,Folks. #4 connection, as Jhdeasy asked? "...What was the function of that fourth jumper?..."

jhdeasy
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Re: MU connections ID?

Post by jhdeasy » Mon Jul 01, 2019 3:06 pm

My speculation is that #4 could be a 27 pin connector used for a communications trainline. This could handle things like public address system, intercom, door control (open/close all doors at high level platform), etc.

Amtrak uses a 27 pin trainline connector for these features. It has a different pin arrangement than the MU trainline connector.

Hopefully a former LIRR employee who worked with this equipment or someone who owns a former LIRR P-75 push-pull car can answer this question.

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