Although an elevator may seem simple, modern passenger and freight hydraulic elevators can handle large loads. These elevators have safety devices that prevent accidents and control mechanisms that can be operated by passengers or operators. Vertical transportation has been using direct-acting hydraulic elevators for over 100 years.
They were originally used for freight but have been a popular choice for passengers and freight applications over the past 50 years. Their dependability, cost efficiency, and reliability made them a favorite choice. They have been used in North America over 500,000 times. Hydraulic elevators are more economical than electric or traction because they don’t require an overhead structure to support them. They can reach impressive heights and have a large load capacity.
There are two main types of elevators in use today: lift spare parts
Hydraulic elevators raise cars by connecting a hydraulic pumping system to a hydraulic ram, which is a piston that is mounted in a fluid-driven cylinder. Hydraulic systems are typically made of oil or incompressible fluids. A hydraulic system is composed of three components:
1. A fluid reservoir (a tank).
2. A pump that is electrically powered.
3. The valve is located between the reservoir and cylinder.
Elevator System Performance Testing
Pre-testing is done to save time and money and to check that the elevator is ready to go for a final inspection. A test will be aborted if there are very few defects.
Newly installed elevators are dangerous. If you have never tested them before, the chances of getting hurt can increase. An elevator mechanic can assist with measurements and observations. The mechanic must verify that the safety circuit works properly. An elevator mechanic must verify that the safety circuit is working properly. The hoistway door interlocks, stop switches, final run-by limits switches, and top emergency exit switch must all be open. This will stop the elevator from running until they are closed.
When testing the speed of a traction elevator, you need to be alert. Be aware of the dangers of rotating equipment in the machine room, such as the hydraulic pump and the pump motor. Without warning, the belt-driven combination can start at any moment. There are also the obvious dangers of falling, tripping, and electric shock.
-All hall and car position indicators and hall lanterns as well as pushbuttons are working.
-Make sure the car’s floor is level at both full capacity and empty loads.
-Verify that the communication system works. It must be an ADA-hands-free telephone system.
-An elevator must be equipped with a Phase 1 or 2 Fire and Smoke detector system that is code compliant and functions as per ASME. The test will not pass if the elevator has code violations.
Hydraulic Elevator Performance Testing
1. The bottom hoistway should be able to see that the automatic shutoff valve has been installed close to the jack assembly. Between the shutoff valve & the jack, you should not use any Victaulic fittings.
2. Before testing the system at twice its working pressure, verify that the contractor has verified that all fittings are in accordance with the specifications.
3. The automatic shut-off valve should be tested by placing the car’s rated capacity on it and performing a terminal to terminal run. The automatic shut-off valve should be activated by the elevator mechanic. The bottom hoistway is used to observe the activation. Overspeeding, overloading or both can cause activation. The pit should not be entered during testing, which will take place from the beginning of the terminal-to-terminal run to the end of the test.
Once the automatic shutoff valve is activated, the elevator should then be started up. The elevator mechanic should then reset the valve. It is important to remove any overloading or excessive speeding conditions and conduct three more terminal-to-terminal runs. The circuit bypass device that was used during the test must be removed. Also, no one should enter the pit for the loading of weights. The test must be restarted if the automatic shutoff valve is adjusted during the test.
4. You can check the amperage of the pump motor using an Amprobe, or an ammeter built into the controller. The pump motor should be at its maximum capacity when it is being run. If the reading exceeds 10% of the amperage rating that is printed on the data tag, it is likely that the motor’s size is inadequate for the load. This means that the motor needs to be replaced. For standard-level elevators rated at between 4,000 and 5,500 pounds, a pump rating of 40-60 horsepower is required. Rarely is a motor with 30 horsepower proven to be adequate.
5. First, check that the gauge is present in the machine room to read the pressure-to-jack assembly. With the full power on the up-run, the pressure should not exceed 500Psi
6. When the unit is being tested, ensure that all required devices, such as the shutoff valves, mufflers, and gate valves, are in place. Any modifications to the hydraulic pipe can cause an increase in pump motor amperage and working pressure. You should not note any modifications to the hydraulic pipe until they are all completed.
7. Perform a 1-hour performance testing – Take temperature readings from the hydraulic oil, pump motor, and machine room with rated capacities, and then begin the 1-hour test. Each floor should have doors that work at all stops. This accuracy must be maintained at both the beginning and end of the test. The test will not be completed if it cannot be run for at least one hour without any adjustments or repairs. An elevator that fails to shut down for a single time with a simple solution is not necessarily an indication that it isn’t ready for final inspection. However, repeated shutdowns are a sign that the elevator isn’t ready.
8. After the one-hour test, the elevator should stop at the stopping level in all directions. Major problems are indicated by a hard stop or start, or any obvious floor level changes. Temperature ratings that rise excessively should be considered a sign that the final test should not take place.
Tests of the Electric Traction Elevator System
1. An Amprobe or ammeter can be used to check the controller amperage. Both directions should be checked with no load and at full capacity. Major motor problems can be identified if readings are more than 5% above the machine’s data tag number.
2. Verify that your car is safe. Once the speed governor has been checked or you are sure it is properly attached, test the safety features with an empty vehicle. The mechanic should activate the elevator and drive the car in a downward direction at inspection speed until the speed governor activates the car safety ties and the wedge is attached to the guide rails.
3. Perform a one-hour performance test. You will need to load the elevator at full capacity. Also, note the temperature in the machine room. The 1-hour performance test should be performed in the same way as for hydraulic elevators. After the 1-hour test is completed, look out for any changes in smoothness and accuracy of floor stops. Check for roll-back after the brake has been lifted. Failures or repeated shutdowns indicate that the elevator is not ready for a final inspection.
4. Buffer tests can be conducted by using the car and counterweights to strike the buffers with an empty load at inspection speed. After each test, verify that the buffer has returned to its original height within ninety seconds. Examine for oil leakage.
5. Oil sprayed on pit walls during the buffer testing or oil seen dripping from elevator car frames after hitting the buffers will indicate excessive oil leakage. This would mean that the buffers need to be replaced or repaired before a final test is possible.
6. Before a final test can be scheduled, any items or parts that are required to be replaced because of failures during the pre-test period would need to be pretested again.
Elevators are generally considered safe and reliable. However, they must be thoroughly tested and inspected before being deemed so. An elevator that malfunctions can cause serious injury or even death. Old elevators may not be maintained or inspected properly, or they might lack the required safety features as mandated by code. Safety codes created by ASME (American Society of Mechanical Engineers), as well as performance testing of elevator systems, are essential requirements.