As the season of Santa, snowmen and single digit temperatures approach in some parts of the world, we thought it would be a good idea to review cold weather operation of your elevator. Believe it or not temperatures can have an affect on how it functions, so here are some things to know.
First, temperatures mean much more to the hydraulic elevator than a traction one. This makes sense as it is a liquid (hydraulic oil) that pushes the car up in a hydraulic elevator. But, there are still some things to be aware of in any traction elevator. Cold temps can make gear grease gummy or sticky causing premature aging of the moving parts. Also, constant shifts from hot to cold temps can create condensation that, although rare, can create a short or other electrical malfunction. Routine maintenance should pick up these issues before they become a problem.
For the hydraulic elevator, the temperature of the machine room is very important and it is recommended that the room generally be between 60 and 95 degrees Fahrenheit for proper function. When the temperature drops below that range for any sustained period of time it can cause the elevator to be sluggish and even cause the elevator to not level properly to the floor. This is due to the higher viscosity as the hydraulic fluid gets colder and thicker and the problems are then compounded by a sluggish valve operation.
Of course the age of your elevator can dictate how it will react in the frigid conditions and some older hydraulic elevators may need seasonal adjustment. Newer models in colder climates can have viscosity control features that heat up the oil in cold conditions.
The viscosity control feature works when a thermostat in the oil tank shows a drop below a certain point, usually 60 degrees Fahrenheit. This will trigger the motor to begin pumping oil without energizing the up valve, the oil will then be cycled through the bypass valve. The pump will continue to run for a couple of minutes then turn off for a while and then cycle again until the oil reaches the desired temperature. The heating circuit operates only when the door is in closed position and no one is trying to use the elevator.
A tank heater, which is a simple, inexpensive electrical coil that is submerged in the tank, can be added to any elevator to keep the oil temperature up.
Also, to help combat cold weather, elevators in the northern United States and Canada often have an extra layer of insulation inside the machine room, around the tank and even around the hoistway.
What happens if the power shuts off? A common occurrence in wintry weather. The first step is to deal with the possibility that someone might be stuck. Here’s a good article on your procedures should that occur. Second, wait for the power to return. Usually, the elevator will automatically restart itself when the lights flicker back on and there should be nothing more than sluggish movement until the oil heats up in a hydraulic elevator. However, some elevators have a specific start up protocol that should only be initiated by a licensed elevator mechanic. When in doubt call your maintenance provider.
With the proper oil and maintenance your elevator should continue to operate flawlessly regardless of how low the mercury falls.
photo credit: <a href="http://www.flickr.com/photos/64749744@N00/3145058104">Let it snow...!</a> via <a href="http://photopin.com">photopin</a> <a href="https://creativecommons.org/licenses/by-nc/2.0/">(license)</a>