Elevator Modernization

D&D Blog

Time for a Cylinder Upgrade!

By: D&D Elevator

Cylinder Replacements

Courtesy: Vertical Express

If today you are operating hydraulic elevators with Single-Bottom-Cylinders, this stands in violation of various state and city codes, as well as the requirements of ASME A 17.1-2000. For several years now, code requirements have called for the use of Double Bottom Cylinders and the replacement of older single bottom installations. These now outdated single-bottom cylinders were the industry-standard until 1971 when codes began to require going to Double-Bottom. Operating with Single-Bottom-Cylinders is risky, dangerous, environmentally unsound and inviting all manner of trouble.

And for good reason: Single-Bottom-Cylinders, by nature of their design, invite the possibility of catastrophic failure in the event that the bottom plate should rupture. Since these cylinders are positioned underground, below pit level, they are subject to sometimes harsh conditions leading to electrolysis and corrosion, which in turn can lead to fluid leaks. Leaking oil leaches into the environment and impacts the performance of the elevator, including possible sudden uncontrolled, downward lurching of the cab. In past years, numerous injuries and even fatalities have been reported as the result of such failures.

Single Bottom Cylinders
Courtesy: Elevator World

Alternatively, Double-Bottom Cylinders protect against bottom plate failures and ameliorate such hazards; these feature – in addition to the bottom plate – a bulkhead inside the cylinder, fashioned with a small opening allowing only a small amount of hydraulic fluid to escape, thereby reducing the risk associated with rapid downward descent of the cab. Today’s code also requires double-bottomed cylinders to be surrounded by PVC encasements, to ward off electrolysis and corrosion; this not only serves to protect the environment but also helps the property owner avoid unpredictable future downtime and expense for remediation of serious problems.

Bottom line, any Single-Bottom-Cylinders remaining in operation at this late date should be upgraded as immediately as possible, to head off a possible catastrophic failure – one which could be potentially and extremely expensive in terms of dollars, downtime and liability. The experts at D&D Elevator stand ready to help you to achieve code-compliance and boost your peace-of-mind!

Preventing Elevators from Shutting Down When Summer Temperatures Go Up

By: D&D Elevator

Maintaining your Elevator Systems for the hot weather ahead

Heat in the cityWith the warm weather and rainy season soon upon us, there are a number of important items requiring attention, to ensure that your systems are properly prepared for the Summer heat and storms.

Priority-one is maintaining the ambient temperature in the machine room. Current code regulations require proper ventilation of machinery spaces and temperature control within a range as specified by equipment manufacturers. Most control system manufacturers require a range of between 50-75 degrees Fahrenheit and machine room air temperatures significantly outside this range can lead to equipment failure. In hydraulic systems, oil is a temperature-sensitive component and overly hot oil can affect operation.

Steps to prevent costly downtime and unhappy tenants if a shutdown occurs

  • Frequently check the emergency call device and lights for proper operation
  • Make sure that your motor room air conditioning and exhaust fans are in proper working order and that thermostat controls are properly maintaining ambient temperature
  • Make sure that ventilation ducts, wall and motor room door vents are working normally and that there are no obstructions limiting the flow of air
  • Make sure your elevator interior exhaust fan is working and that it is running during hotter Summer days
  • Check for water leakages in the machine room, including joints of window frames, to avoid damage to critical components

air conditioner 60 degreesBrownouts & Blackouts

During heat waves, there is vastly increased demand for electricity, which can cause momentary power loss, a reduction in voltage and longer-term power outages. In such event, best practice is to remove the elevator from service and immediately notify your elevator company.

  • First and foremost during a power outage, make sure that persons using the elevators in your building are not trapped or in need of assistance  
  • Momentary loss of power can cause the elevator to stop, the doors to malfunction, or the system to attempt to reset by skipping floors and moving to the terminal landings
  • A reduction or fluctuation in voltage can cause intermittent failures of components, which will momentarily stop the elevator or doors from operating. Such “ghost calls” can be problematic since, by the time technicians arrive on site, the voltage may have returned to proper levels and they cannot see the problem in progress. It is important to report these intermittent failures to the technicians to avoid any inconvenience to the riding public.
  • Brownouts are a normal recurring issue during the hot summer season. If you are experiencing a brown out, you must check the elevator equipment to ensure it is working properly. Brownouts can cause major damage to motors and motor control equipment. “Single Phasing” of 3 phase electrical equipment will cause motors to burn out and contactors to weld closed.

D&D Can Help!

The experts at D&D Elevator stand ready to evaluate your particular needs, assist you with preventative maintenance and respond to you immediately in the event of an emergency.

Modernizing Single Speed AC Traction Elevators

By: D&D Elevator

Single SpeedSingle-Speed AC (SSAC) electric traction elevators – now obsolete and no longer made or installed – are most commonly found in older residential buildings. They first appeared during the post-World War II period, often installed as upgrades to earlier, prevalent DC systems as the municipal trolley grids that powered them became extinct, with installation continuing well into the 1970s. Popular at the time because they were attractively priced, they typically appeared in low- to mid-rise residential buildings, including condo conversions and rental apartments.

Current owners and managers of such properties who continue to operate these elevators are urged to seriously consider upgrading their equipment to modern standards, and there a number of compelling reasons why. Continued operation of this outdated technology presents many potential hazards and problems best to avoid:

  • Code compliance issues
  • Ongoing repair and insurance costs
  • Risk of downtime
  • Risks to passengers and exposure to trip-and-fall litigation

SSAC elevators are slow, single-speed, low-capacity passenger units that are prone to intermittent leveling fluctuations. As such, they present trip-and-fall hazards, particularly to elderly passengers and those with mobility disabilities who may find it extremely difficult to negotiate level differences. This problem is caused by their reliance on brakes to stop the car in properly level position, which often can be imprecise and inaccurate.

stop at floorConversely, today’s elevators have abandoned the use of brakes to stop the car, instead employing VVVF (Variable Voltage-Variable Frequency) control systems that consistently stop the elevator at floor level within tolerances of ¼-inch. As their name implies, these adjust both the voltage and frequency of the power applied to the hoist motor, thereby varying the speed at which the motor operates. With this technology, the hoist motor can be brought to a so-called “electrical stop” – with the hoist motor energized but not turning. This allows floor stops to be accurately specified, without regard to the load in the car.

Current New York State code requires that elevators, when arriving at a floor, stop accurately and consistently within a finite limit of ½-inch above or below floor level. This is reflected in the current edition of The American Harmonized Elevator code (CSA B44/ASME A17.1). The Technical Standards & Safety Authority (TSSA) has also written on the matter, recommending that these elevators, because of their poor leveling ability, should be upgraded.

D&D Can Help

The experts at D&D Elevator stand ready to help you evaluate your particular needs, to cost-efficiently achieve safety, code-compliance – and peace-of-mind!