Home Forums General Discussion Technical Questions Overheating Hydraulic oil

Elevators are about 23 years old. Now during the summer months, the oil overheats and the pump shuts down... on 4 elevators. What should I look for as the cause. Do not want to install oil coolers. Worked fine all these years.

Making sure the tanks are holding all the oil they can is about the easy way to start. But just becaue it just started the best question to sak is what has changer. The number of people in the building. The type of buisness in the building. Relocation of smoking area or cafateria. If all units now do something they never did before what has changed??? Oil coolers may be the only answer to your problem.

since all 4 lift have the same fault then it cant be a stall situation. i would also agree that the duty cycle needs to be looked at as remeber they only have a certain amount of starts per hour and heating the oil v cooling of oil is not linear. it takes alot longer to cool than heat. so i would look at-

add oil to the highest level you can to the tank.

check the duty cycle of the building and assess wether it has changed.

add more time to door dwell for a longer time between travel of the lift.

if all else fails and/or you are unable to change anything the only real solution is an oil cooler. ive installed these coolers to hydro's on my round where lifts were constantly going out of service to zero call backs. they arent cheap but you need to sell the idea to the customer what would you prefer? o-o-o lifts or lifts that work.

dont forget a/c in the machine room, leveling times, oil warming function and a piston full of oil. these can also heat up oil. more than likely its over usage or global warming, either way oil coolers will make them more reliable.

all 4 elevators do it so i think these guys got it figued out the a/c in motor room broke or it's getting alot more runs ...time for oil cooler's

That kind of heat is bad on the equipment. Call the Inspector, get him to force the customer to pay for air conditioning or coolers. You just have to prove that the oil temp gets above manufacturer recommended limits, that along with the controls. I think the major valve companies say > than 140� and all bets are off.

I use a temperature sensor, about as big as one of the old pagers, that I place in an inconspicuous area. You can set it up to take readings at programmed intervals, ie; 1 minute, 5 minutes, 15 minutes, whatever you wish. They will record for many months. Then you take them back to the shop, and print out a graph, showing the temperature in the room. If the a/c ain't working, then the troublecalls are billable. There's your proof.

http://www.dicksondata.com/products/SP125

Hydros put out about 20,000 BTUs an hour, (very roughly, and of course depends on a myriad of factors). The a/c system needs to be able to extract that amount of heat out of the machine room, times how many elevators are in there. Many architects overlook this, to the customer's detriment.

Like greenpants said, reduce leveling times. That helped me once.

Maybe the oil is losing is lubricity? There are friction modifiers you can add, short of changing the oil. Your local supplier should be able to test a sample of what's in your tanks for you.