Sunday, December 17, 2017

Elevator motor control – Generator versus motor drive

I was doing a walk through on four elevators that we needed a number of things for and I was looking at a older Virginia Controls elevator with a MG set.  This controller had one cabinet for the controller portion and one for the generator and motor control.  The other passenger elevator in the building had been modernized and had a motor drive.  It was a night and day example of how technology removed so many failure points from the elevator system on traction cars.  At one point in the elevator universe this was cutting edge technology, but technology moves on. 

Existing machine – This was a machine most likely replaced in the late 1980’s early 1990’s.  Good bones, if it where to be replaced again it would be replaced with a machine just like it. 

Existing controller – Holy smokes this has a lot of relays in it.  How many guys carry a relay tester in their car?  More relays more potential problems.

Existing Generator – This is an item that kept elevator guys busy changing brushes to keep the generator going.  There is an art and a process to replacing brushes.  If a generator is not maintained it will be a very expensive proposition to repair or replace it.  Oh yeah there is also generator dust.  The 2nd picture is the data tags from the generator, there is an incoming AC side and an outgoing DC side.  It took me a few years to wrap my head around this when I first started in the business.

Existing motor control panel – This is a panel with resistors, relays and phase protection.  If you look you can see there still is a mercury phase monitor on this controller.  Be careful how you dispose of this, mercury does not go away and is dangerous.

New style motor control – This box which is approximately 24” x 18” replaces the giant motor control panel and generator.  There are maintenance items to perform on this device but not nearly as much as the generator.  This is a great device, it makes life a lot easier for elevator technicians.

Why did this elevator have a generator? – Back before the motor drive was invented they used DC power to allow the elevator to have better leveling accuracy.  AC power plugs into the generator and DC power is sent to the motor.  It got rid of the floor accuracy problems of single speed AC motors and two speed AC motors. Tesla Vs. Edison. Tesla won but…. Edison’s DC power was cleaner, efficient and easier to control.  But you needed generators nearby.  Tesla’s AC could but run with wires over long distances without generators nearby.  AC power also fluctuates over time, in America 60 times a second. 

Take away – For most applications you can get rid of the elevator generator and you will get rid of a lot of your headaches, or potential headaches.

As always feel free to contact us at, email or call 630-766-7230.

Sunday, December 10, 2017

Elevator controller hall of fame – part #1

Here are a few of our better controller pictures of the last few years.  These typically make us cringe when we see them, hopefully they are going to be moded, but sometimes we decide it is a good idea to do maintenance on them.  I want to know when the person who was working on some of these controllers decided it was time to stop and throw in the towel.  There is one picture of one of our accounts we inherited and we went on to clean up the wiring. Each picture has a bit of the back story and narrative below it.

This is from an elevator in Oak Park, IL.  While the controller is troubling to look at there was exposed multicable run in the machine room and car top, I’ll share those pictures with you later.  We didn’t end up getting this modernization but we did get the 2nd car to do a year and a half later.

It is always cool to go to a building where the company you work for originally installed the elevator system 40+ years ago.  In this case Colley installed this elevator in Hickory Hills, IL in the early 1970’s.  What is not cool is to see what someone has done to this controller over the years.  A few minutes after I looked at the controller and took the information down I went in the car and saw there was a bullet indentation in the car door.  I stared at it thinking… why would you shoot a gun at the car door?  The shooter was standing in front of the door, there is no hole in the cab door, just a dent, where do you think the bullet went?



 This is what I call a Friday at 4pm repair.  You are supposed to go back and eventually correct what you did to get the elevator running.  Well… It wasn’t corrected.  We went in an straightened out the wiring in the controller and in some electrical boxes.  This is a pretty cool before and after photo.  

[Car #1]

[Car #2]

 The next two are controllers that for some reason we thought would be a good idea to take on maintenance.  This may come to a shocker, some of the features didn’t work right. This controller installation is a disservice to our trade.  The company who installed these was so proud of their work they wrote their name with sharpie on the machines they installed.

I was at a State of Illinois Fire Marshall Elevator meeting and a building was brought up to explain why they haven’t done X, Y & Z.  There was a spirited debate and the inspector who went to the building stated “this was one of the worst examples of “maintenance” he has ever seen”.  I was curious about what could be so bad and thought perhaps the inspector was exaggerating.  About 4 months later I got a call for a 2 car modernization from someone I worked with while he was working for a different building management company.  He explained the situation and I said “ah ha! I know this building from the State of Illinois meeting!”.  When I got there, I saw what the inspector was talking about, it was all true.  Did you know Montgomery Elevator dabbled in oral hygiene in the mid 1960’s?  

As always feel free to contact us at, email or call 630-766-7230.

Saturday, December 2, 2017

Hydraulic elevator modernization – Chicago, IL.

This is from a building that we just modernized.  The elevator was originally a Otis Elevator from 1965. We have previously replaced the cylinders in the building due to the City of Chicago cylinder mandate.  The elevator was in rough shape when we completed the cylinder replacement 3+ years ago.  When I went back to do the engineering the car ran like a cross between a haunted house and carnival ride. We did not maintain this elevator prior to modernization.

  [Old Machine room layout]

 [New Machine room layout]

Elevator Controller – On this project we used a Smartrise Engineering hydraulic controller to replace old Otis relay logic control system.
[Old Otis controller with finger contacts circa 1965, lots of relays and contact points]

[New Smartrise hydraulic controller]

Elevator power unit – We replaced the Otis dry power unit that was leaking everywhere that had a previous valve replacement with a MEI power unit with a  UC4 valve.

[Old dry power unit]

Elevator fixtures – We used Innovation industry surface mount hall stations to cover the existing fixture holes at 50”+ and bring the button down to 42”.  The car station has a digital position indicator, emergency light, emergency phone and ADA compliant buttons.  This building owner wanted a different type of push button style then we typically use.

[Old Otis car station with phone offset]

[New Innovation car station]

[Old Otis hall station with button at 52" +/-]

[New surface mount Innovation hall station with push button at 42" ADA compliant]

Elevator door operator – We replaced the old Otis door operator with a new GAL MOVFR II.  We replaced all the car and hatch equipment with new Otis door parts.

[Old Otis door operator held together with electrical tape]


[Old Otis car door set up]

[New GAL MOVFR II car door set up]

I always like seeing the before and after of our modernization projects and see the dramatic transformation.  This elevator should be good for 20-30+ years.

As always feel free to contact us at, email or call 630-766-7230.