Aluminum wiring - Elevators

I was at a few buildings this week where I saw aluminum wiring.  For those who are not familiar with why we in the elevator business [or any electrical related field] cringe when we see aluminum wiring is because it causes a lot of problems.   Many times we address the symptom of the "electrical issues", not the cause[which can be the aluminum wire].

Case - We had a building where the elevator kept setting the motor starter overloads, typically this is from over current on the motor which identifies a malfunction somewhere or a low voltage issue from the building power.  We worked on this problem for over a week on and off and building was very frustrated.  We looked further into the electrical and found there was a loose connection/melted connection on the vault that was causing more issues then just the elevator problems.  The elevator mechanic's trouble shooting typically stops at the disconnect, in this particular situation the mechanic went further and discovered the root problem which was a bad connection on a lug in the electrical room.  It was an expensive resolution for the building but it saved the building from a fire and future electrical issues due to the bad connection points from the aluminum wiring.

Aluminum wiring got to be popular in the mid 1960’s when the price for copper increased.   This is also the time where there was a building explosion in the Chicago land area.  How does this affect your elevators?  It can lead to motor burn out, starter malfunction and general reliability issues.  And it is difficult to find because the aluminum wiring issue may be in the elevator disconnect, electrical breaker where the elevator disconnect gets power, vault termination or anywhere in between there is a connection point.

[This is a picture of the main line disconnect the aluminum wire is coming in from the top which is feeding power from the building feed to the disconnect and copper wire is on the bottom feeding the elevator motor starter]

[This is a closer picture of the connection points on the disconnect - you can see the color difference between the wires, top wires are aluminum and the bottom right connection shows the copper wire]

  

Aluminum oxidation

Most metals (with a few exceptions, such as gold) oxidize freely when exposed to air. Aluminum oxide is not an electrical conductor, but rather an electrical insulator. Consequently, the flow of electrons through the oxide layer can be greatly impeded. However, since the oxide layer is only a few nanometers thick, the added resistance is not noticeable under most conditions. When aluminum wire is terminated properly, the mechanical connection breaks the thin, brittle layer of oxide to form an excellent electrical connection. Unless this connection is loosened, there is no way for oxygen to penetrate the connection point to form further oxide.

[oxidation]

Coefficient of expansion and creep

Aluminum wire used before the mid-1970s has a coefficient of expansion that varies significantly from the metals common in devices, outlets, switches, and screws. Many terminations of aluminum wire installed in the 1960s and 1970s continue to operate with no problems. However, problems can develop in the future and some connections were not made properly when installed, including not wrapping wires around terminal screws and inadequate torque on the connection screws. There can also be problems with connections made with too much torque as it causes damage to the wire.

Aluminum and steel both expand and contract at different rates under thermal load, so a connection can become loose, and loose connections get progressively worse over time. This cycle results in the connection loosening slightly, overheating, and allowing intermetallic steel/aluminum alloying to occur between the conductor and the screw terminal. This results in a high-resistance junction, leading to additional overheating. Although many believe that oxidation was the issue, studies have shown that oxidation was not significant in these cases. The problems related to aluminum wire are typically associated with older pre-1970s solid wire smaller than No. 8 AWG, as the properties of that wire result in significantly more expansion and contraction than modern day AA-8000 series aluminum wire. Older solid aluminum wire also had problems with a property called creep, which made the wire permanently deform or relax over time under load.

[What can happen with creep]

Joining aluminum and copper wires

Another issue is the joining of aluminum wire to copper wire. As aluminum and copper are dissimilar metals, galvanic corrosion can occur in the presence of an electrolyte and these connections can become unstable over time.

Tin coated copper wire 

There is also tin coated copper wire which can be confused with aluminum wire which is similar in color to aluminum wire.  I was recently corrected by an electrician when we where reviewing the electrical wiring at a school.

The point is that if you have aluminum wire, you should remove it.  If you choose to keep it you will need an electrician to tighten connections and maintain the wiring to prevent shorts, fires and unreliable electrical connectivity on regular intervals.  

If you have an questions or would like information from Colley Elevator you can go to www.colleyelevator.com, email Craigz@colleyelevator.com or call 630-766-7230.

Weather changing, elevator lubrication & elevator maintenance

In the Spring and Fall we get more than our ordinary amount of calls for the elevator making “strange noise”.  When the weather changes it effects the composition of the lubricants we use on the elevator system, which we need to address by adding more or removing the existing lubricant and adding a different type. 

There are a few areas on elevators that may need more attention when the warmer weather turns to dryer colder weather two of them are the rails and the hydraulic gland packing.

Hydraulic elevator rails – The rails should be lubricated and as an elevator maintenance provider we need to pay attention that the rails are lubricated with the correct lubrication especially during the fall and winter months.   The lubrication also protects the rails from corrosion caused by humidity and environmental pollutants.  The lubricant should remove some of the resistance or “chatter” that causes noise and lets the elevator have increased ride quality.   The proper process is to provide a very light coating with a cloth that is nearly invisible.   The rails should be cleaned before you apply a new type of lubricant.

Traction elevator rails – Same lubrication information as the hydraulic elevator except we need to be sure that the lubrication does not interfere with the function of the safeties.  Lubricant that does not break down under pressure may inhibit the elevator safeties ability to work properly.  A lubricant that does break down under extreme pressure will allow direct unlubricated contact between safeties and rails and allow the safeties to operate within the set stopping distance required by code.

[This is a random elevator I visited last week we do not maintain this elevator - the picture  is to show the different application of elevator traction versus hydraulic]

[The elevator safety is on the left which engages with the rail to stop the elevator in the event of an over speed in the down direction emergency - we do not maintain this elevator]

Hydraulic cylinder packing – During the transition between Summer and Fall or Fall to Winter we may feel hard starts and stops on the elevator system. We can add a product called Max Glide, made by Maxton Manufacturing[www.maxtonvalve.com] that will reduce or stop harsh stops and starts.  This product can be put on the elevator piston as well as put in the hydraulic  power unit reservoir.   This may be effective for a few days, a few months or years depending on the composition of the hydraulic cylinder gland packing.  If the Max Glide does not work, you most probably will need to repack the elevator cylinder gland.

[The cylinder packing is in-between they cylinder and the piston, the shinny long object]

www.maxtonvalve.com

As an elevator maintenance provider we should be monitoring the lubrication of the elevator and have it on a lubrication schedule.

If you have an questions or would like information from Colley Elevator you can go to www.colleyelevator.com, email Craigz@colleyelevator.com or call 630-766-7230.

Associa Cares – Proposal Palooza – 10/10/14

Yesterday Colley went to Associa’s “Proposal Palooza” which is an expo where vendors get to meet and interact with property managers and building decision makers[board members].  For those who are not familiar with Associa they are a company that has brought together two great companies; Vanguard Community Management[they are the great property managers at my town home association] and Legum & Norman, Midwest. This was the first expo we had gone to in a long time and I’m glad we went. 

The previous years we had donated items to the auction which I had no idea where the money went to.  This year during lunch we got to know about Associa Cares which is the philanthropic arm of Associa.   We were also entertained by Elliot from Art Beat Live, whom put on a great show. 

http://www.associacares.com/

We got to learn about the great things that Associa Cares does which include assisting in natural and man-made disasters.  We did not donate to the auction this year as we had a booth, after learning about the great things Associa Cares does we just donated to the cause[today].  Not only is Associa a great property management firm they do something great with their outreach and influence.

Here is a picture of our table we had.  I believe our booth was a bit under dressed compared some of the other exhibitors, however, next year we will be back and have some great display pieces and have exciting take aways which I still owe some of the community managers.  Our goal will be to have a donation to the auction that everyone will talk about during the expo!

Proposal Palooza was a great event and a great experience. I got to see people who I have only talked to on the phone or haven’t seen in years.  I have been working in the elevator business for 17 years and it is always nice to finally meet or reconnect with people that you have been sending letters to or calling for a very long time.  Nothing can replace a face to face hello.

If you have an questions or would like information from Colley Elevator you can go to www.colleyelevator.com, email Craigz@colleyelevator.com or call 630-766-7230.

00 Elevator electrical requirements /arc flash

There are National Electrical Code[NEC] requirements that are being enforced by some in some facilities.   I was in a facility last week and was requested to use OO electrical gloves if I were to work on any live elevator circuits.   I was at the building to assist the fire protection company resetting the elevator system so there was no need for the OO electrical gloves.  If I needed to touch the live elevator controller, I would need the gloves.  You can turn the power off and work without the gloves. Please see what the gloves look like below.  The gloves are an item that the elevator company should provide.

For elevator personnel work it is very difficult to work with these gloves on but it is a requirement in some facilities.  The new requirements are for the safety of the elevator mechanic or apprentice.  Some facilities in the future may require electrical protection matting.  The matting is an item that the building owner should provide.

Please keep your eyes out for tags like these and make sure that you have the proper protection equipment if the building is requesting it.  The tag will indicate what class of gloves you will need. 

  

If the building would like you to wear a rubber suit and they are willing to work with the elevator company to pay for the suit and the time it takes to work with the suit on and wearing the suit does not compromise your safety, you must wear it.  The electrical code is changing to increase electrical safety, while it does inhibit our ability to perform efficiently and effectively at times we must respect the building owner’s request.

The likely hood of a request for elevator personal to wear a arc flash suit is very low.  All electrical safety requirements should be discussed at the office level before the elevator personnel arrives on site so the person going to the facility can be prepared.  

Also when working on electrical equipment you must wear cotton long sleeves so if you are a person who wears short sleeves on a regular basis, make sure you have a cotton long sleeve shirt in your car in the event you visit a facility with strict safety requirements.

If you have an questions or would like information from Colley Elevator you can go to www.colleyelevator.com, email Craigz@colleyelevator.com or call 630-766-7230.