By: D&D Elevator
Found these days in older residential buildings, Single-Speed AC (SSAC) electric traction elevators are now obsolete and are no longer made or installed. Current owners and managers of such properties who continue to operate these elevators are urged to seriously consider upgrading their equipment to modern standards, since continued operation of this outdated technology presents many potential hazards and problems best to avoid:
SSAC elevators 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. These elevators are slow, low-capacity passenger units that are prone to intermittent leveling fluctuations. Since they rely on brakes to stop the car in properly level position – which often can be imprecise and inaccurate – 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.
Conversely, 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!
By: D&D Elevator
With NYC DOB, Appendix K3, Rule 3.10.2, the New York City Department of Buildings mandated that – by January 1, 2020 – “all automatic passenger and freight elevators must provide a system to monitor and prevent automatic operation with faulty door contact circuits.” That deadline has now passed and it is urgent for those who have not complied to do so immediately to avoid potentially serious consequences, including the possible issuance of fines and shut-down of your elevator(s).
In mid-2018, we began notifying our NYC customers of this mandate and deadline. We sent proposals individually tailored to each customer’s elevator equipment, followed by several email reminders and phone calls. With the deadline passed now more than ever, time is of the essence – material and permit lead times can be weeks from receipt of signed proposals and required deposits.
D&D Can Help!
At this late date, we will do all we can for our NYC customers. If you have not done so already, we urge you to please submit your signed proposal and deposit so that we may schedule your elevator(s). We welcome your calls with any questions you may have, (914) 347-4344.
By: D&D Elevator
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.
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!