Cal. Code Regs. Tit. 8, § 3088 - Screw Type Elevators
(a)
Hoistways, Hoistway Enclosures and Related Construction. Hoistway, hoistway
enclosures and related construction shall conform to the requirements of
Article 7, except as the requirements for elevators with screw type hoisting
means are modified by the following:
(1)
Section 3010. (Hoistway Enclosures) Safe
access to the hoist machines located on the car or in the pit shall be provided
from the machine room at the lowest landing or pit level. The access door shall
be electrically interlocked to prevent operation of the car when the door is
not closed and locked.
(2) Section
3011. (Machine Room)
(A) Hoist motors, rotors, brakes and
reduction gears may be located on the car top or in the pit provided.
1. Hoist machines located on the car top are
permanently enclosed so they are inaccessible from the car top.
2. Access to drive machines mounted on the
car or located in the pit is from the bottom level machine room only. An
enclosure shall separate the drive unit on the car or in the pit from the
machine room. Access doors shall comply with the requirements of Section
3088(a)(1).
(B) Screw fastenings, car lowering mechanisms
and car overspeed governors may be housed in a removable enclosure secured
against unauthorized access.
(C)
Where the drive unit of a screw type elevator is located in the elevator pit, a
permanent means shall be provided in the pit to support the car and platform
during repairs or adjustments of the unit. Clear headroom under the platform
shall be not less than 7'0" when the elevator is landed on the
supports.
(3) Section
3017. (Top and bottom runbys and
clearances)
(A) Elevator top and bottom
clearances and runbys shall comply with Section
3017 for elevators with electric
drive motors and Section
3054 for elevators with hydraulic
drive motors.
(B) The bottom runby
required by Section
3088(a)(3) may be
eliminated where spring buffers complying with Section
3088(b)(1)(C) are
provided and the speed of the elevator as it approaches the landing is not more
than 10 feet per minute and the spring buffers are not compressed under normal
operating conditions.
(b) Machinery and Equipment. The machinery
and equipment for elevators with screw type machines shall conform to the
requirements of Article 8 except as sections are modified by the following:
(1) Section
3031. (Car buffers)
(A) Spring buffers used on elevators with
screw type drive machines shall be so designed and installed that they will not
be fully compressed when struck by the car with its rated load at governor
tripping speed.
(B) Buffer design
shall consider the energy of the rotating machinery and shall provide an
average deceleration of not more than 1.0g for oil buffers and a maximum
deceleration of 2.0g for spring buffers.
(C) Where recoil of the car upon impact with
the spring buffers is detrimental to the screw, dampening shall be provided by
means of a hydraulic or pneumatic device to eliminate any recoil.
(D) Calculations satisfactory to the Division
shall be provided for each spring buffer design and rating.
(2) Section
3063. (Car frames and platforms)
Car frames and platforms shall comply with Section
3063.
(3) Sections
3035 and
3036. Car safeties and overspeed
governors. Screw elevators whose screws have not been shown to be capable of
supporting 125% of the rated load and the car weight both in compression and
tension shall be provided with car safety and overspeed devices of an approved
type. Car safeties and governors shall comply with the requirements of Section
3035 for safeties and Section
3036 for governors.
(4) Section
3038. Screw machines shall comply
with the requirements of Section
3068, Section
3104 and Section
3038 except subsections (a) and
(b).
(A) In the design of screw machines, the
load to be used in computing factors of safety shall be the maximum load
imposed when lifting 125% of the rated load.
(B) For design purposes, screw machines shall
include hoist and pump motors, gear boxes, sprockets, brakes, brake drums or
discs, screws, screw supports and fastenings, rotors, lowering mechanisms,
pumps, hoses, and other equipment necessary to raise and lower the
elevator.
(C) The hoisting screws
of screw machines shall have a factor of safety of not less than 15 based on
combined tension and torsion stresses when lifting 125% of rated load and
combined compression and torsion stresses when the screw is supporting 125% of
rated load when used as a column.
(D) Where the rotor or nut travels with the
elevator, the machine except for the screw, shall be inaccessible from the
elevator car top and from outside the hoistway. Provisions shall be
incorporated in the design of such a system for manually lowering the elevator,
from the bottom machine room, to gain access to the machine. This manual
control shall be failsafe and have a dead-man control. The lowering means shall
be adjustable so the lowering speed is less than one-half rated speed with
rated load on the car and shall stop and hold a load of 125% of rated load.
This adjustment shall be set and sealed at the time of the initial inspection
and at periods not exceeding 5 years.
(E) Machines in which the screw is stationary
shall have the screw restrained at both the top and bottom ends to prevent the
screw from rotating except when the car is being lowered as required by Section
3088(b)(3)(D).
(F) The screw shall be supported vertically
and horizontally in such a way as to eliminate those forces or torques not
taken into consideration in the design. Factors of safety required by Section
3104 shall be based on loads when
lifting 125% of rated load.
(G)
Drawings showing details of the entire screw machine and appropriate
calculations by a California Registered Engineer shall be provided before the
first machine of a kind and rating is installed and when requested by the
Division. The calculations shall show the stress in all critical support
members and major components of the machine. Where screws are spliced, the
details of the splice shall be acceptable to the Division.
(H) The hoist machine brake shall be located
so there is no coupling between the brake and screw or rotor.
(I) Belts and chains shall not be used except
where multiple-link silent chain is enclosed in a transmission housing. When
multiple-link silent chain is used, its wear shall be monitored with a chain
switch to remove power from the drive machine motor and brake when chain wear
or stretch becomes excessive.
(J)
Hoist machine brakes shall be released electrically or hydraulically and
applied by springs.
(K) A flexible
hose supplying high pressure fluid to the hoisting rotor motor shall comply
with requirements of Section
3068(a)(3)(B)
except that where the failure of a hose will not result in lowering the car the
hose shall have a bursting strength sufficient to withstand only 4 times the
working pressure and shall be tested in the factory or in the field prior to
installation of a pressure of at least 2 times the working pressure. Flexible
hoses shall in addition to other criteria be designed to withstand the flexing
to which they are subjected.
Notes
2. Renumbering of former Article 12.3 (Section 3088) to Article 12.6 and new Article 12.3 (Sections 3085-3085.22) filed 6-9-86; effective thirtieth day thereafter (Register 86, No. 24).
3. Editorial correction of subsection (b)(4)(K) (Register 95, No. 34).
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
2. Renumbering of former Article 12.3 (Section 3088) to Article 12.6 and new Article 12.3 (Sections 3085-3085.22) filed 6-9-86; effective thirtieth day thereafter (Register 86, No. 24).
3. Editorial correction of subsection (b)(4)(K) (Register 95, No. 34).
Group II regulations apply to existing elevators installed prior to October 25, 1998. Italicized paragraphs, sentences, or phrases apply to all existing elevators while non-italicized apply to elevators installed after 1970 or after the date the regulation was adopted.
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