NR NR/L2/SIG/11766/A040 ISSUE 3 PDF

INTRODUCTION1

TI21 Tuning Units and ETUs are known to be prone to connection problems at the T1/T2 terminals where the track tails are terminated onto the unit. Investigation has shown that the termination arrangements for the 10mm tail cable crimp can become slack owing to the ‘Back nut’ becoming loose (see Photo 1). The resulting loose connection causes degradation in performance, often leading to right side failure.

For new build Tuning Units and ETUs, Bombardier have altered the terminal arrangement to remove the ‘Back nut’ and these units are identified by mod strike as follows:

New build TU with modification = mod strike 3

New build ETU with modification = mod strike 4

This application note contains:

• Instructions detailing how to modify the terminal arrangement of earlier TUs and ETUs to eliminate the slack back nut problem.

• Recommendations for Tuning Unit trackside wiring which will optimise pole/zero performance

1 The illustrations in this application note are clearest when viewed in colour.