Hello everyone,

We have TBQD card in S processor for proximitors in mark v.Recently we found this card is not working. We changed the card and found there is no power supply 24v for proximitors on the card terminals. Since the supply for TBQD is taken from the Tcqb card in R processor, we changed that card also but still the problem persist. I am getting 14v on only terminal 105 only. What would be the possible causes and what else remaining to change?

i have still some doubts

1)Is power supply for TBQD card and proximitors supply(24v) taken only from R processor

2)Getting 14v only on terminal 105 only on the new card also

Pls suggest me

Cheers,
prasath

 

Hi,

Please consult Application Manual GEH 6195 Appendix D for details of connections in MKV.

Terminal 105 (together with 106 and another pair: 107/108) on TBQD on <S> are miliamper outputs. On terminal 105 you can find positive voltage vs ground P24. 14V that you see it is drop of voltage on the external circuit.

Supply to proximitors come to TBQD from TCQB by ribbon cables JLL-R/JLL-S/JLL-T. Check if you have these three cables.
As supply to proximitors you expect to see N24 vs ground on respective terminals.

Supply to proximitors and to miliamper outputs come by the same ribbon cables but through different wires.

On TBQD, supply to proximitors passes through the CL (current limiter). Check for short circuit somewhere on the external circuit.

Check power supply voltages on R/S/T using Diagnostic Counters screen.

Regards

 

hi,

thanks for the reply.I removed all the connections coming from the field and the card is fully isolated from the field. after that only i have changed the card. Even after that also i didn't get any voltage on the terminals except 14v on 105 terminal.

one more thing,as you said that power supply is coming thru JLL-R, S, T, But i removed both JLL-S & T cables but still 14v comes on 104 terminal..

i hope the power supply for the card is coming from R only.

cheers,
prasath

 

Prasanth,

Is there any fuse connected to the line, please refer the drawing in the <PD> core.

Take care
G.Rajesh

 

rajesh,

there is no individual fuse for that card, and its common supply taken from TCPS card in R processor

cheers,
prasath

 

Hi,

There are fuses on power supplying cards TCPS, on processors (R/S/T/C).
Please check carefully, they are well hidden, if I am not wrong there are four on each card.

One of them protects N24V.

On TCPS cards there are also testing points with description, so you can identify TP for the voltage you are interested in and measure with voltmeter that you have this N24V available.

Regards

 

Hi Prasath,

We have send it out for repair to dejongeurope.eu for professional repair with GE certificates. They also stock MKV. Good luck!