Home Forums General Discussion Technical Questions Otis 50 UCL Loop circuit

I have a 50 ucl. When it first starts in the morning it will make 3-6 trips fine. After that intermittently it will run up and down on leveling speed. Motor fields good. All contactors are up. I believe that the problem is in the loop circuit, but I'm not sure the sequence and have some conflicting prints for this job. Are there any old otis guys that have info on this? Or a write up?

thx.

I would look at the speed step circuit. What ever pulls in 2E and FE is where your problem lies. Relays may be up, but I would start pulling on shuts and looking for relays that are slow to pull in. What is your car speed? Do you have an advancer motor?

Yep i would say if your speed relays are up then it is most likely in the GLF resistor section(where the step relays short out the resistor) and there is a open circuit under load on a wire or contact. This also applies to the GSEF also. The current must going thru the resistor systems, so to prove which area is to place a short across each section 1 at a time and see if the lift speeds up.

Unfortunately it is a fact of life, to work on any older equipment, no matter who manufactured it, you need to be able to read and understand a straight line wiring diagram. You need to be able to ask yourself questions like. It won't run up.Why? It runs slow. Why? If you are unable to do that you should ask for help from your Super. Mechanics that can read and understand a Straight Line are becoming few and far between.

Make sure all your contacts and contact shunts are good by making sure you have zero ohms. An Otis 20 and 50 have a GDF which is an extra Field in the Generator that is opposite polarity of the GF. The GDF is energized to decelerate the Unit smoothly. Also Mark wires and disconnect all generator field wires and check for a leak between each of the Generator field windings (GLF, GDF, & GF). Any ground in the loop circuit can cause your symptoms on a self excited GF. Could easy be a leak in Generator Interpole or Motor Interpole leaking to Ground after it warms up. A Motor shop can Meg Test the Motor-Gen. Service the GF and GDF resistors on the controller for a bad connection. PM me an email and I may have an adjustment procedure for the control.

For those of you who have tried to help THX. This unit does not have the speed step relays that you are speaking of. It predates 1E, 2E, FE etc. But thanks for your input. John Jay, I have been in this business for over 20 years. I have extensive print reading ability. As you can see Rolly had actual valuable information. That helps me decipher the prints. I can read a print. Obviously, you don't have the knowledge to understand my question. Sounds like another old guy that thinks all the knowledge is leaving the business when they do.

Thank you everyone else.

Ive been in this business for 20 odd years now..mostly with the big O.....and I'm a bit confused on what you actually want....Otis have been using the 1E, 2E etc from day dot...and to say that someone doesn't have the knowledge to answer your question is downright rude!!!!You don't know the answer so why say that!!!...the answers that have been given are a VERY good start (and very informative to me too) so have you ACTUALLY taken the advise or just poo pooed it thinking it isn't going to help!!

jdog,

Probably a good idea to change your handle for the next time you need help from this forum

Old Guy

Well Gentleman the speed step relays on that Equipment with a De-Mag Field is 1G and 2G. IT was BEFORE 1E, 2E or E1A E2A. I started with Otis in 1963.

I stand corrected about the numbering, just have never come across them.!!as they say you learn something new every day!!!

Kiwi I've never seen this stuff either, and don't think that version ever made it to Aus. I've worked on 1950's installs, and it was the 1e,2e type and no GDF generator either. Must have been pretty early installs, that never made it here.

I have scanned the documents. there are 2. One is 5mb other is 2mb. If your interested in receiving a copy PM me.