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  • PROBLEM IN 26L BRAKE SYSTEM

  • Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.
Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.

Moderator: GOLDEN-ARM

 #232042  by BRAKEMAN
 
Hi;
I am brake engineer . we have u30c & u30c-7i locos. this locos is equiped with A-1 valves . when break in two is accured from 7th wagon and after that ,break in two protection dont work . please help us to solve this problem.

 #232299  by Realityrail
 
Which of the following occurs?

1) Emergency Brake Application: Brake Cylinder does not increase to emergency pressure

2) Emergency Brake Application: PCS OPEN Light does not illuminate and engine does not return to idle (PCS OPEN light bulb and circuit are functioning properly)

3) Emergency Brake Application: Is there a 20 second delay from the break in two until the PCS OPEN Light illuminates?

 #232473  by BRAKEMAN
 
WHEN BREAK IN TWO IS ACCURED FROM 7TH WAGON AND AFTER THAT THERE IS a 4-5 MINUTE delay from the break in two until the PCS OPEN Light illuminates. BEFOER 7TH WAGON DELAY TIME IS OK.
* OUR WAGONS DONT HAVE NO-8 VALVE.
WHAT DO WE DO TO DECREASE THIS DELAY TIME TO STANDARD?
PLEASE GUIDE US.THANKS.

 #232562  by LCJ
 
Seems to me you need more vent valves to propagate the emergency application after break-in-two. The A-1 valve senses an emergency rate of reduction -- or in your case it doesn't. Vent valves speed up the air flow on longer trains and longer equipment. What is the length of your individual "wagons?"

 #232875  by BRAKEMAN
 
OUR WAGON'S LENGHT IS APP. 11-15 m . They dont have any vent valve and we cant equip them with these valves . please help us to solve this problem . can we install H-5 valve in brake circuit to solve this problem?

 #233645  by BRAKEMAN
 
THANKS LCJ
But in addition to u30c locos we possess GT26 locos that is equipped with H-5 valves. if we use NO-8 valves in our wagons GT26 locos break in two system dont work properly and pcs light illuminate Consumedly because H-5 valves is very sensitive.
Can we use H-5 valves in U30C locos?

 #241128  by Clyde
 
The conventional H-5 Relayair valves configuration is obsolete and has been replaced with the A-1 Charging and Cut-Off valve in the industry since many years.

Obviously the fact that the cars are not equiped with #8 vent valves doesn't help at all. However I assume that the locomotives are equiped with at least one vent valve at rear end.

Suggestions:

1. Make sure port #1 fo A-1 C&CO valve is pipied DIRECTLY on Brake pipe trainline with 3/8 OD copper tubing (type K I guess).

2. Make sure there is no restriction at all between A-1 C&CO valve pipe #1 and traniline.

3. If not existing, equip locomotive with Low Brake Pipe Pressure Switch (LBPS) (EMD part 9518549 or equivalent). LBPS shall be piped on Brake Pipe close to trainline (not on A-1 C&CO pipe). LBPS is normally wired on PCS circuit in order to initiate power knockdown when Brake Pipe pressure drops at switch drop out set pressure (39 psi). Power can be restore through LBPS when Brake Pipe pressure is increased above switch pick up set pressure (45 psi).

4. An Air Flow Meter is also a good mean to monitor Brake Pipe pressure along the train by loco. engineers.

Good luck !
Clyde

 #244397  by BRAKEMAN
 
VERY GOOD.
THANKS.