Home Forums General Discussion Technical Questions Dover relay logic oildraulic

This is a relay logic Dover selective collective with 4 stops inline. The old IBM relay controls. The car responds properly to the hall calls. But when more then one car call is put in the car skips the first call and stops at the furthest car call out.
So if I have the car at the bottom landing and I place a 2nd and 3rd landing car call the car skips the 2nd and then stops at the 3rd. The selector is stepping in its proper sequence. When 2a1 and 2a2 pickup 2c cancels and the car goes to 3. 3a1and 3a2 pick, CC picks, CS picks and the car comes to a stop.
We are going back on Monday and I would appreciate anything you can share. We do have prints. And it seems that what ever picks and drops CC happens too quickly. And CC doesn't have enough time to pick when there is more then one car call.

cs has to pull in to stop, therefore Lr and sp have to pull in. The contact on cc and that pulls in sp is a suspect.

Thanks for the response John. I believe my trouble has to do with V (slowdown). Ill keep you posted!

I found the CS2 contact that is use to short out CC constantly made. One of those blasted needle contacts!

Thanks

I used to think that an oletimer was just lazy by telling me to check every IBM relay. He would say pull them out,blow them out and look at them. He would not even trace the schematics. He also liked to say the female plug contacts could be loose, so squeeze them tight before you plug each one of the relays back in. Any time there was an issue that was not obviously a mechanical problem this was his solution. The crazy thing was once he was called in,the same problem never happened again. And it was never a parts charge. Just labor.

Now we have the yellow jacket relays, in every unit that has not been modded.

Thosec aren't helpfulat all, they prevent you from being able to circuit trace. That is the worst situation you could be in. A little idiot light (led) doesn't solve your problem. Nothing replaces good old troubleshooting.

Thank s for the responses

Solid State

The old timer had definitely pass on some of his wisdom!

I've no experiences with the yellow jacket relays. Every unit I've seen with these relay base type has had the IBM relays. I will say it is nice when you trace the trouble out that you can see the faulty contact.

Philly
What is the function of the LED? To tell you the coil is energized?

Also, thanks Jim Collett the sequence info for call canceling was spot on!

Yes...I can attest that the above method does work. Back then it was part of routine anual maintenance. In this day and age for a building to pay the kind of money to keep one of these things in tip top shape, it is far more cost efficient to modernize.

I agree Broke Sheave! Unfortunately the last repair we had for this unit was during a pressure test. The inspection switch on the car top snapped off. That was over 3 years ago. This was our second call since I took it on 6-7 years ago. How do you convince a customer to modernize their elevator when it runs so well?

This unit is the exception to the rule.

Surely Broke Sheave, you are not saying that you are an ole timer?

LOL.

I remember Pickett's charge at Gettysburgh..LOL..

One of the younger guys that works with us now told me this story. When he first hired on in the Elevator Business he worked for a non-union company and he went around cleaning pits and machine rooms for a long time, that's all he ever did. Eventually he assisted the owner in some troubleshooting etc. etc. until he got familiar with some of the equipment. So then one day they gave him boxes of titanium wire contacts and told him to go to a composite job and replace all of them in the controllers... Needless to say, when he turned the first car back on it wouldn't run... After hours of troubleshooting they got the car back running. I usually don't clean or replace contacts unless I know for sure that they are causing a problem - a very wise older Elevator Wizard gave me that advice.

If it aint broke dont fix it.

I worked with several old timers in the 70's on all manner of relay control. One of them was a DMR ace, and he insisted that I, being the young helper should blow out those controllers, with a cadillac blower, annually.

The 1st time I did this of course the car would not run and I called him to the machine room to assist me. He told me.

"DAMNIT, Just KEEP BLOWING TILL IT RUNS. DON"T YOU KNOW ANYTHING?"...LOL...

on fridays never pull your tools out of the truck after lunch unless absolutely necessary.

You are indeed a wise man Green Pants.

UC,CC and DC are 32 volt relays (black coils) make sure know one has changed one out with a 48 volt or worse a yellow jacket.

Green pant
There is wisdom in your words...

TKE
This unit uses 26 volt black coils for UC, DC, & CC. The prints at this job were in mint condition. The voltage difference is clearly indicated on the print. and Jim Collett reached out with a description of the canceling sequence for this circuit. So Monday when I walked into machine room I was good to go!

Thanks for the heads up.

I'm no fan of yellow jackets, or any other relative of bees personally.
Watch out for the wire slipping down in wcr relay those are FUN.....
Also the little plastic pieces that go around coils do get brittle and will cause you grief as well,
Here is a hint as well, put a change date on those with magic maker
After year or so I change them out.... Less trouble
And lest I forget the brass sleeve on 14/15 switches on composites....
For the new guys