Home Forums General Discussion Technical Questions TAC-20 Open Fuse CNWI F-3

Hello,

We have isolated our issue but can't find what it's feeding. CNWI board opening F-3 MDA-2 immediately when wire P24 wire #1 CON9 is applied. Anyone know what this is feeding or have prints for this location.

It feeds everything that’s 24v in the controller. If P24 reads short to ground with power off troubleshooting will be easier, otherwise you’ll have to lift wires and go through a few fuses. I would start by lifting the P24 travel cable wire and P24 to the hoistway or LN card then see if the short still exists in the controller or is in the car or hoistway. You can isolate the 188e by unplugging con9 and con11.

I will check it out. Thanks for the information.

Those little 2 amp in-line circuit breakers from amazon work good for this type of troubleshooting. Make sure and reset the circuit breaker with the power off.

pull con 7,8,9,10 see if fuse holds, looks like a good place to start

Thanks for the help. Here is what we found. We replaced the LN board but now we have another issue? notes from mechanic: I replaced the LN board then found blown pico fuse ..traced it to an L24 board with a blown semi conductor. And , replaced it. All the boards were then online and took a call , but, the valve never got power to the coil from the 188E bd. It would just bypass until it went on low oil timer. So the up high speed coils were lit on the I/O screen but, no magnetism on the coils themselves. I wasn't able to determine the issue but these faults are indicating software or. 188e board needs replacing. I reinstalled original LN board thinking it was in need of programming. But , it made no difference. Car is on inspection in MR with the left bypass switch.

The LN board definitely will need to be programmed so if the original isn’t bad, use it. I would replace the pico fuses with the correct size if you were blowing F3 on the CNWI from a bad L24 card. If the up valve outputs (VC4A & VC4B) are high but the up fast coil isn’t magnetized, first is put a meter across the coil (CNWI Con17 pins 7 to 8) to see if it has voltage (coil could be open). If no voltage you’re going to need the “Motor and Valve Control” page of the print and a meter. Read AC voltage from ground to 122 (source) then 131 (after the DLT relay) then 134 ( should have voltage there if you have it at 134) then Con16-7 on the 188e. Give it an up high speed run and check from ground to Con16-8 (after the 2 valve coil relays on the 188e K7 and K8). If you have voltage there, leave one lead of your meter there and move the ground lead to the TSL2 relay 11/14 contact. If you aren’t getting ground through there, either TSL2 relay is not picked or it’s 11/14 contact is bad. If you didn’t have voltage past the K7 & K8 relay at Con16-8 on the 188e it’s probably a bad contact on one of those relays. You can put the car on inspection and inject VC4A, you should hear K7 relay pick. Inject VC4B, you should hear K8 pick. If they both pick but you don’t get voltage through them, replace them.

I will have a look and let you know what we find. Thanks,

Well, rechecked and tested all relays. D7 was bad and D1 was iffy as well. Replaced both and rechecked all connections. Elevator is back in service, I appreciate the help.