Hello elevator people. I have been a mechanic for 10 years now but have only been in the service department for about 3. I guess you could say I was "thrown to the wolves". We have a 16 story building with 3 Otis passenger cars and a simplex freight. My boss in his infinite wisdom decided to blow out the generator on the freight car. Even after EVERYONE tried to talk him out of it. Needless to say, it started throwing fireballs immediately. We ended up pulling the armature and having it rewound. That was about a year ago. This elevator has not been right since.
To start off with it had all the turns in the MG. We took some out and that would let it stay running. After having 5 or 6 different mechanics take turns moving resistor bands and selector switches it has become my responsibility to make it run correctly. After solving lots of issues I have it to the point where it runs but something isn't right.
When it runs in the down direction the genny will squeal a little when it takes off. Brushes arc a little bit but not bad. It levels in just fine. In the up direction it is a whole different story. It takes off and runs fine until it starts to slow down. When FE drops out so does 2E. the genny SCREAMS and throws sparks bad. Then it will level in and stop just fine.
It also will violently re-level in both directions but only at the top terminal landing. It also does it at the only rear opening which is the second landing but only when you run down to it. If you run up to it from the bottom terminal it doesn't do it. At one point when I first started working on this unit it did it at every landing in both directions.
I have corrected so many issues it would be impossible to list them all. At one point it was blowing coils on my slim line relays. I have replaced 15 of them I would guess. I have a book that dates from June of 1974 that I refer to as my bible. It has helped me get to this point but I am officially at my wits end. I guess what I really need help with is figuring out why the MG is squealing and screaming like it is. As far as I can tell all the relays are doing what they are supposed to do with the exception of 2E.I assume there is more than one issue at work here. It is a 21 UCL controller with a 6850 selector. No advancer panel. 350 FPM car. It uses an 82GA generator. I'm sure I haven't provided enough info but could use any help with this. I have no way of knowing what all has been changed since this started a year ago. It is running 340 FPM in the up and 320 FPM on the down.
I can only begin to express the respect I have for the guys that worked on these units for years back in the day. I have learned a lot since taking this on but know I haven't come close to being in the same league as some of the guys I know around here. Most of them are retired now. So if I can provide any info let me know. Any help is greatly appreciated.
Rando

Rando, blowing out a generator is part of the trouble shooting process and yes sometimes it will make things worse but more times than not it will eliminate grounds. But first back to the basics. What do the Generator and hoist motor Meg out to? You must remove brushes and motor leads and Meg everything to see if you are getting any grounds. Then you can hook your field coils to 110VAC and see if you have a even voltage drop across each one. Once you know you have an ungrounded and equal system you can start setting up your compounding and speeds. Also load weighing is huge on these cars as far as adjusting is conceared. So if people have been doing 5 year full load testing without jacking up the platform bolts I can assure you you will have problem there. Get a megger and some weights and start from scratch. You can never adjust an elevator that has grounds that may be changing by thousands of OHMS due to changing condishions like temputure and moisture. Good Luck!!!

Rando will PM you my phone number. Was a 45 HR (12.5%) paid Adjuster with Otis. Adjusted many of these new when I worked at Otis. Tell me where your located in PM so we can set up times to talk. There are so many issues from what you typed it is almost impossible to type all of them. A 21UCLS is a geared machine, usually max 350FPM or slower and a usually a 71GA Generator ( Maybe an 82GA if very high car capacity, or 63GA if very low Capacity and 200FPM).

Rando, don't feel bad about a genny blow out. It was always part of the Otis maintenance program and yes if not done a lot, it can cause problems. Just an immediate thought from me is to check the neutral plane on the genny first.

Dan- Why check the coils with AC and not DC? Just an easy access for you guys from a power socket outlet? And when you say the jacking bolts, do you mean the rope standing end bolts?

I think the inductive reactance that causes the voltage drop across the field coils isn't accurately measured without a changing voltage. The same reason you can set neutral with AC from the wall but if you use DC you have to switch it in and off to read the deflection. And in my experience DC is much more accurate to set neutral. I have found especially on these old Otis machines guys like to bump neutral around to address any leveling problems. However there is more than just that going on here. Talking to a guy like Rolly in this stuff goes a long, long way. There is precious little of this kind of experience left out there.

And please correct me if my AC field drop test theory is erroneous.

Actually guys the best neutral setting on a Machine is same exact speed or RPM at No Load on machine (Exact Balance load in car). An 1/8 of an inch will make 10-15FPM difference. On a generator you need to read the flux from field to get it to zero deflection. If your deflection was positive then move to zero until it goes negative them move back to as close to zero as possible. That should be neutral. I always used a 100 watt resistor from rectifier voltage to energize the field. Also do generator with only 2 brushes in not all 4, then make sure brushes for 4 are quartered. What you are actually doing with the deflection is finding where the generator brushes dissect the flux at center of the field. Mechanical center is a place to start, but can be different then the electrical center thus why you use the deflection. Obviously you have to disconnect generator field wires to apply voltage for deflection since the field in this generator is a self excited field. (No external voltage source other then induction from the leveling field to build up to contract speed). Always used main field wires, never got enough deflection using just leveling field. Also on some larger generators (95 115 1B 2B 3B) Otis will take one pole of the leveling field and make it the comp field for load weighing compensation so you may not have correct fields energized for accurate reading on those units.

I have some old Otis adjusting manuals that say to set neutral with 2 "test brushes" or make your own by filing brushes to a point exactly on the centerline of the brush so they only contact one bar each. After setting the brush angle and quartering of course. Never gone that far myself but it is something to think about. I use 6vdc batteries and a 50mv analog DC meter in a little apparatus I made for setting neutral.

That should work fine also..

uppo72, I was so new I didn't even know to question why AC vs DC. When I was taught that way by the wizard from the motor shop and a 30yr adjuster and have just done it like that for years.... As far as the jack bolts Otis used a isolated 2 piece platform with isolation pads between the two sections. The load weighing switches are set as the isolation pads compress with a load. And the jack bolts are located on all 4 corners so you can run them up and keep the isolation pads and switches from getting creamed when you do a full load full speed safety set. And if you do not run the jack bolts in you will have to reset all the load weighing switches or as we find on a lot of jobs we take over. Have poor leveling performance with the need to bring in weights to set things backup. I have been trying to find a newer style load weigher to replace the old micro switched but i am having problems finding any with the 6 or 7 outputs needed to replicate the Otis design. Including anti nuisance and hall call bypass.

Dan thanks for the reply. In Aus we have 230/240 vac on the wall, so not sure id want to do that but can get info from the motors winders if need be. As to the jacking bolts, that is a name used for a variety of spots so thanks for clarifying it. It is a good point about the adjustments as I have worked on a lot of 260vip where the selectors are all worn out, and then the compo settings are out too. I didn't realise we could jack those up, but it should be remembered that it is only a recent rule change that we had to do full load safety gear tests, as we only did hand control tests, which is where the damage was avoided. Not sure of a new product to replace this either.

Uppo72- not to get off topic but I visited Sydney Aus in 2010 and cant wait to retire and get back for an extended visit.

Its great, but since im a melbonite, we have a better city!!!!! I recommend touring NT and the Kimberleys in WA.

Just a quick follow up to my problem. I finally got ahold of the Otis genius in our area. He is retired now but was my teacher all the way through elevator school. After eliminating the controller we focused on the loop circuit. I have an 82GA MG set that will allow up to 12 turns. I had 4 in it at the time. He had me take ALL the turns out. Something I wasn't even aware was possible. That fixed all my major issues. I had to tweak the selector and the speeds but it is running better than ever. I would again like to tip my hat to the guys who worked on this equipment for years. I don't know what we will do when they are not around to bail us young punks out. I guess we will just mod it when it breaks!! Thanks to everyone for your replies. Hope this helps someone else down the line!!
Rando