(a) Type Required.
(1)
Buffers or bumpers shall be
installed under the cars and counterweights of all cable-driven power
elevators.
EXCEPTION: Counterweights of existing elevators which
have never had bumpers or buffers.
(2)
Spring buffers, oil buffers, or
their equivalent, shall be used on all cable-driven power elevators.
EXCEPTION: Solid bumpers of rubber, wood, or other
material having similar shock absorbing qualities may be used on:
1. Existing installations of solid
bumpers.
2. Existing elevators
having a rated speed of 50 feet per minute or less which have never had
bumpers.
(3)
Oil
buffers or their equivalent shall be used where the rated speed is in excess of
200 feet per minute.
EXCEPTIONS:
1.
Installations of bumpers or spring buffers made before June 5, 1947.
2. Where Type C safeties are used, solid
bumpers may be used under the car.
(b) Location.
(1)
Buffer or bumpers shall be
located symmetrically with reference to the vertical centerline of the car
frame or the counterweight frame, within the tolerance of 2 inches.
The car bumpers or buffers shall be located so that the bottom runby
does not exceed 24 inches.
(2)
Buffers or bumpers shall be
located in the pit.
EXCEPTIONS:
1.
Oil buffers mounted on the counterweight.
2. Existing buffers mounted under the
car.
(c) Stroke
of Spring Buffers. Spring buffers shall be constructed so that the stroke of
the buffer spring, as marked on its marking plate, shall be equal to or greater
than the following:
Rated Car Speed Feet Per
Minute |
Stroke In Inches |
100 or
less.......................... |
..........................1
½ |
101 to
150.......................... |
..........................2 ½ |
151 to
200.......................... |
..........................4 |
(1) The
spring buffer shall be mounted so that the spring will be compressed solid
before the car or counterweight rests on the buffer
support.
(d) Load Rating
of Spring Buffers. Spring buffers for cars and counterweights shall:
(1) Be capable of supporting, without being
compressed solid, a static load having a minimum of twice the total weight of:
(A) The car and its rated load for car
buffers.
(B) The counterweight for
counterweight buffers.
(2) Be compressed solid with a static load of
3 times the weight of:
(A) The car and its
rated load for car buffers.
(B) The
counterweight for counterweight buffers.
EXCEPTION: When Section
3019(a)(2)
necessitates a greater load rating.
(e) Marking Plate for Spring Buffers. Each
spring buffer shall have permanently attached to it a metal plate marked in a
legible and permanent manner to show its stroke and load rating. (The load
rating is the load required to compress the spring an amount equal to its
stroke.)
(f) Stroke of Oil Buffers.
The minimum stroke of oil buffers shall be based on the requirements outlined
in Design Section
3108(a). Table
3031 F indicated the minimum buffer strokes for the most usual rated speeds.
EXCEPTION: When oil buffers are used in conjunction
with an emergency terminal stopping device conforming to the requirements of
Section 3039(c) which will
limit the speed at which the car or counterweight can strike its buffer the
following shall apply:
1. Reduce
stroke oil buffers may be used on modernization installations in existing
hoistways provided that the stroke of the buffer shall be as long as possible
for the existing conditions.
2.
Reduced stroke oil buffers may be used for new installations when installed as
follows: The buffer stroke shall be based on at least 115% of such reduced
striking speed on an average retardation not exceeding 32.2
ft/s
2 (9.81 m/s
2). In no
case, shall the stroke used be less than 50% of the stroke required by Section
3031(f) for rated
speeds under 800 fpm (4.06 m/s), nor less than 33-1/3% or 18 inch (457 mm),
whichever is greater, for rated speeds of 800 fpm (4.06 m/s) or more.
NOTE: See Section
3031(m). Testing
of Oil Buffers.
TABLE NO. 3031F
Minimum Buffer Strokes
Rated Speed In Feet Per
Minute |
115% of Rated Speed in Feet Per
Minute |
Minimum Strokes of Oil Buffers In
Inches |
|
200.......................... |
230 |
|
2 ¾ |
|
225.......................... |
259 |
|
3 ¼ |
|
250.......................... |
288 |
|
4 ¼ |
|
300.......................... |
345 |
|
6 ¼ |
|
350.......................... |
402 |
|
8 ¼ |
|
400.......................... |
460 |
|
11 |
|
450.......................... |
517 |
|
13 ¾ |
|
500.......................... |
575 |
|
17 |
|
600.......................... |
690 |
|
24 ¾ |
|
700.......................... |
805 |
|
33 ¼ |
|
800.......................... |
920 |
|
43 ¾ |
|
900..........................
|
1035 |
|
55 ½ |
|
1000.......................... |
1150 |
|
68
½ |
|
1100.......................... |
1265 |
|
83 |
|
1200.......................... |
1380 |
|
98
½ |
|
1300.......................... |
1495 |
|
115
½ |
|
1400.......................... |
1610 |
|
134
½ |
|
1500.......................... |
1725 |
|
154 |
|
1600.......................... |
1840 |
|
175
¼ |
|
1700.......................... |
1955 |
|
197
¾ |
|
1800.......................... |
2070 |
|
221
¾ |
|
1900.......................... |
2105 |
|
247 |
|
2000.......................... |
2300 |
|
273
¾ |
* Where buffers of the
stroke specified are not provided, the requirements of Section
3031(f) exceptions
apply.
GENERAL NOTE:
1 fpm=5.08 E-03 m/s
1 in.=25.4 mm
(g) Retardation by Oil Buffers. Buffer
retardation rates shall conform to the requirements of Design Section
3108(b).
(h) Factor of Safety for Oil Buffer Parts.
The factor of safety of oil buffer parts shall conform to the requirements of
Design Section
3108(c).
(i) L/R for Members Under Compression as
Columns. The L/R ratio for oil buffer members shall conform to Design Section
3108(d).
(j) Plunger Return Requirements. Oil buffers
shall be so designed that:
1. The buffer
plunger of the gravity-return and spring-return type oil buffers, when the
buffer is filled with oil, shall, when released after full compression, return
to its fully extended position within 90 seconds.
2. The plunger of a spring-return type oil
buffer with a 50 pound weight resting on it shall, when released after being
compressed 2 inches, return to the fully extended position within 30
seconds.
3.
Car and
counterweight buffers of the spring-return type shall be provided with a
switch, operated by the buffer in case it is compressed more than 3 inches, and
so connected to the control circuit that the speed of the descending car or
counterweight shall not exceed ½ the rated speed unless the buffer
plunger returns to within 3 inches of its normal position.
EXCEPTION: Elevators with buffers installed before June
5, 1947.
(k) Means
for Determining Oil Level. Oil buffers shall be provided with means for
determining the oil level, and that the level is within the maximum
and minimum allowable limits. Glass sight gages shall not be used.
(l) Approval of Oil Buffers. Every type oil
buffer shall be approved by the Division of Industrial Safety before
installation. The approval shall be based on tests witnessed by a
representative of the division, or certified test reports as specified in
Design Section
3108(g) may be
accepted.
(m) Testing of Oil
Buffers. On each installation of an elevator equipped with oil buffers, a field
test of the buffers shall be made, and witnessed by a representative of the
division, consisting of running the car with rated load onto its buffer at
rated speed and the counterweight onto its buffer at rated speed with the car
empty. In making these tests, the normal terminal limit switches shall be made
temporarily inoperative, and the final terminal limits shall remain operative
but shall be temporarily relocated if necessary to permit full compression of
the buffer during the tests.
EXCEPTION: (Section
3031(m))
Reduced stroke buffers shall be struck at speeds
reduced to conform to the stroke of the buffer used, and the test shall
demonstrate that no part of the car or counterweight will contact the overhead
structure. Failure to so demonstrate shall require adjustments or modifications
acceptable to the division.
(n) Load Ratings of Oil Buffers. The minimum
and maximum load ratings of car and counterweight oil buffers as indicated on
the buffer marking plate shall conform to the following:
1. The minimum load rating shall be not
greater than:
(A) For car oil buffers, the
total weight of the car as marked on the crosshead data plate plus 150
pounds.
(B) For counterweight oil
buffers, the weight of the counterweight used.
2. The maximum load rating shall be not less
than:
(A) For car oil buffers, the total
weight of the car as marked on the crosshead data plate plus the rated
load.
(B) For counterweight oil
buffers, the weight of the counterweight used.
(o) Oil Buffer Marking Plate. Every installed
oil buffer shall have securely attached thereto a metal plate, marked by the
manufacturer in a legible and permanent manner, indicating:
1. The maximum and minimum loads and the
maximum striking speed for which the buffer has been approved.
2. The manufacturer's identifying type or
number of the buffer.
3. The
permissible range in viscosity of the buffer oil to be used, stated in Saybolt
Seconds Universal at 100 F.
4. The
viscosity index number of the oil to be used.
5. The pour point in degrees F. of the oil to
be used.
6. The
stroke.
Notes
Cal. Code Regs. Tit. 8, §
3031
1.
Amendment of subsection (f), Table No. 3031 F and subsection (m) filed 5-12-83;
effective thirtieth day thereafter (Register 83, No. 20). Approved by State
Building Standards Commission 4-4-83.
Note: Authority cited and Reference: Section
142.3, Labor
Code.
1. Amendment of
subsection (f), Table No. 3031 F and subsection (m) filed 5-12-83; effective
thirtieth day thereafter (Register 83, No. 20). Approved by State Building
Standards Commission 4-4-83.
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.
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.