DAILY EXPERIENCE OF AN ELEVATOR ENGINEER 2; TROUBLESHOOTING

Today, 23rd of May, which is a Saturday morning, My colleagues, and I went on to check up an elevator of a site located at Oniru Lekki, Nigeria.
The elevator was known to always have a drive problem. The drive of the elevator has been damaged twice and was just recently repaired after we were called upon to check on the elevator before powering it up for use.

AN ELEVATOR DRIVE

On arrival in the site location we had to check the reading of the 3 phase power to the lift. we first read the voltage reading from phase to phase before reading phase to neutral, then we read neutral to earth, the readings were okay. Then, we had to check if we get the same reading at the controller room

So when getting to the last floor of the building, I noticed a funny issue which is the location of the controller room. As I said in my previous post, some lifts have their control panel situated at the last floor of the lift while some at the roof of the building. This elevator had is controller room, and motor at the roof, but the passage to the roof was quite dangerous to use. So, we had to be careful when using the ladder.

Below are pictures of the passage to the controller room.

Below is the picture of the controller room

After reading the phases, there was an issue with the reading of neutral to earth. The reading was over 4.0 and that kind of reading is enough to damage the drive of the elevator. The reading of neutral to earth should not be more than 0. and if there are any leakages not more than 1. So, I had to check the reading in the voltage regulator and found it read the same over 4.0 to neutral to earth.

Neutral to earth reading

So to solve this issue. We had to check the contacts of the wires going through the VR (voltage regulator). We made sure all wires is well in contact by removing and tightening back each wire. All this had to be done to make sure there are no leakages. After doing all this, we rechecked the reading, and we got a reading of 0.3 which was okay to use.

Reading of VR before adjusting phase contacts

Adjusting phase contacts properly

Neutral to earth reading after adjusting contacts

Reading of the VR after adjusting contacts

After powering the elevator, the drive gave an error code; error 41 which means safety incomplete. The next thing was to check what could have triggered the error code, so, I went to check the safety switches in the pit, which is located in the shaft of the lift, which are the buffer switches and governor switches.