Home Forums General Discussion Technical Questions oildraulic. ibm relay

Stupid question: Every other week go to building thats 7 stories, Dover Oildraulic, iBM relay controller. Before I arrive, building maintenance main lines which clears faults. Report that comes in to me.....Elevator at lobby (lowest landing) with hall calls all fired, door open, low oil board low, and elevator will not run. It's a simplex.
Thanks

Chi
LO relay is tripped by LOT.
I would look to see why LOT tripped LO.
LOT may also be use as a redundancy for your motor starter and the overload. An example would be if your 3 phase contactor single phased. LOT would see that the car is trying to run longer then it would take to go from the bottom to the top floor. LOT would time out and picks LO. LO is self holding. When the maintenance man pulls the main line he is dropping out LO.

I suggest you start with you contacts on the motor starter. See if they are pitted or hanging up.

Sounds like your up terminal limit is not made or your OL contact is intermediatly acting up...car wants to drive up. Whats stopping it? Your LOT is a delay on timer that is started by an Up aux contact. I don't have a print in front of me but what in your circuit would prevent your starter from engaging or your car to run up the h/w at a reduced speed....Check your LOT timer by removing the OL wire or starter coil wire make sure it trips at the same time everytime usually around 90 secs. If you have any difference just once on your test change out timer. The components on those rc timers deteriorate all the time causing false fires, replace with an artisan timer. Also make sure your valve is sized right meaning its not bouncing on the bypass. When it comes to LOT or MLT it can be a nightmare to t/s but thats why you get paid the big bucks anybody can vacuum a cartop but theres a select few who can shoot the trouble. Good luck.

Good point Sccjr.

Chicago,
Is this unit relay logic like the old fleetwood model or solid state?
Do you know the drawing numbers?

Most common reasons I have found for LOT. #1 LOW OIL #2 bad aux contacts on starter...#3 bad Valve adjustment on sizing or leveling....#4 Bad lot timer....#5 tripping lock and causing car to go to up level speed on a long floor and LOT trips. (not sure on Dover but I have seen this on other manufactures) GOOD LUCK!!!!!

The last three WRC controls to fail this way was fixed with a new valve kit.

Lets look at the symptoms- Report that comes in to me.....Elevator at lobby (lowest landing) with hall calls all fired, door open, low oil board low, and elevator will not run. If the car is on LOT, the doors would be closed and there would be no hall calls entered. Throw the cat into LOT and see if this is the case. If so, then you are probably looking at a (cannot close the doors) problem. When you say- hall calls all fired- does this mean also the 1st floor up fired? Are there any car calls fired? Is the 1st floor car call fired? Do hall calls cancel when you reach the DOL or when you arrive at the floor? What bypasses the DCL to keep power on the operator during a run? Could DCL be not making? Why does MLR release the car? There is no mention of car position, above the floor, below the floor, or at floor.
What door operator is this using? Is this only after a weekend or does it happen during the week? What kind of building? Could be a problem in the CS circuit locking it up.

Stupid question 2: The same call came in the other day. Elevator at lowest landing, several car calls fired, door open, and elevator would not leave first floor. Building Eng. pulled main line to get elevator running due to heavy traffic in apt. building. Maintenance person called me before he pulled line to reset, LOT timer board not on. I arrived hour later and went over first floor lock, pick ups and clutch clearance thru hoistway, check starter contacts, etc. History... 7 story Dover Oildraulic controller, IBM Relay logic(about 50 IBM relays), 4 timer boards, 24 years old equipment, Dover door operator(85?) with micro-switches, maintenance man tells me that he pulls main line every other day so he does have to waste my time.
Thanks for any ideas.

I hate calls like this. I have a hotel that won't wait for me to get there and mainline the car (especially trap calls). Then, they send emails complaining about repeat problems....

Chicago,
If it's the circuit I'm thinking of?
When the doors open fully DS should pick.
DS drops CS,
CS drops SE,
SE then picks CD.

You may want to pull each relay and check the contacts. I've found them pitted or shorting across the normally open and normally closed contacts.

If its got an I2 valve...check your up leveling screen. If its clogged up...change it, don't even try to clean it

Thanks...DS-timed door close
CS-car stopping
SE-safety edge
I was driving home thinking.....lost....position?
1A position first landing
1A2
1c car call
1u-up hall
2A- position second landing
2a2
2c car call
2d car call
2u up hall call
ETC
CC car call transfer
sorry.....it was a HD-73 operator...thinking of DMC-1 job
This has hatch switches
92 relays
5 timers
Thanks again... be there wed for maint.

Chicago
The hd-73 changes things up a bit. The relay sequence is not what I posted earlier.

Does this unit have viscosity control "TLO, TST, TS relays"?

Chicago, did you check for a stuck button or relay on the lowest landing holding the doors open? Ask the maintenance man is the bottom landing button on in this situation.

Stupid answer.....thanks for your help fellas. I stop by job site to perform maintenance. Found Dover care top guides came loose and had too much play w omega rails. Elevator would move just enough away from leveling circuit (three switch) to make car act like inspection mode, doors open and no door action. IN and INX de-energized. Maintenance man has not re set main line for week.