In Canada, cathodic protection was popular in the late 1980s and early 1990s but slowly disappeared with PVC encapsulated cylinders became popular and easy to install. Also, elevator consultants preferred the PVC over the cathodic protection because it is maintenance free.
By 1996 new elevators in Ontario for example were equipped with PVC protection. In Alberta, this did not become law until circa 1999. Again, elevator consultants were specifying PVC protection albeit it was not required by code. With PVC, cathodic protection became less common and yes, elevator companies stopped installing it or even paying attention to it.
Companies designing and building cathodic devices for elevators either went out of business or focused their attention on other industries interested in cathodic devices like pipelines, gas lines, etc...
When the US elevator code ASME A17.1 and the Canadian CSA B44 code were harmonized circa 2002 and on, the new harmonized code (in stages) adopted various aspects of ASME A17.1 and vice versa. So, in the Canadian Provinces where the joint harmonized code B44-00 was adopted, cathodic control became not only acceptable, but also equivalent provided that the cathodic device was maintained on a regular basis. This gradually spawned a new life into the cathodic devices and "forced" property owners and managers to invest in these devices to bring them back to life. However, not all consultants are aware of this fact or believe in the viability of the cathodic system. We have noted on many occasions where these devices were disconnected (with the blessing of the elevator consultant) during a modernization because the elevator contractor did not want to deal with the cathodic unit.
Cathodic protection is based on a simple theory that corrosion is electrical in nature and occurs when metal come in contact with a conductive element. This conductive element can consist of liquids or solid materials including soil. When the metal (or in our case the cylinder) conducts current, the point of contact between the cylinder and the soil, water, etc… oxidizes and rusts. Therefore, protection of the metal by means of overpowering or stopping the current is how cathodic protection works. There are two basic methods of applying cathodic protection: sacrificial anodes and impressed current cathodic protection. Most elevator systems utilize sacrifice anode. However, the biggest problem we see with these systems is that the control unit is typically not working.
So, the best way to keep your cylinder healthy and ensure that it meets the latest and greatest code requirements is by having the unit tested and maintained on an annual basis by specialists. Otherwise, you would have to spend anywhere between $35,000 to $65,000 to replace the cylinder.
