ISO/TR 11071-1:1990

TECHNICAL ISOITR
11071-1
REPORT
First edition
1990-12-01
Comparison of worldwide lift safety Standards -
Part 1:
Electric lifts (elevators)
Comparaison des normes mondiales de s&urit6 des ascenseurs -
Partie 7: Ascenseurs tYec triques
Reference number
ISO/TR 11071-1 : 1990 (E)
ISO/TR 11071-1 : 1990 (El
Contents Page
1 Scope .
2 Terminology .
Basis for lift safety Standards development . 2
4 Spates and clearances . 8
5 Door Systems and interlocks .
Kineticenergy . 11
................................................. 14
7 Tractioncalculations
8 Safetygear .
9 Overspeedgovernors .
.......................................................... 17
10 Buffers.
11 Braking Systems .
.................................................... 20
12 Electricaldevices
Annexes
A Tabula~ons. 23
Al Spacesandclearances .
A2 Door Systems and interlocks . 29
A3 Kineticenergy . 33
A4 Trac~on .
A5 Safeties .
A6 Overspeedgovernors . 37
Buffers . 41
A7
A8 Brakingsystems .
AS Electrical Devices .
B References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C CEN/TClO/GTl/NVME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0 ISO 1990
All rights reserved. No part of this publication may be reproduced or utilized in any form or by any
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writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
ISO/TR 11071-1 : 1990 EI
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of
national Standards bodies (ISO member bodies). The work of preparing International
Standards is normally carried out through ISO technical committees. Esch member
body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, govern-
mental and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
The main task of ISO technical committees is to prepare International Standards. In ex-
ceptional circumstances a technical committee may propose the publication of a
Technical Report of one of the following types:
-
type 1, when the required support cannot be obtained for the publication of an
International Standard, despite repeated efforts;
-
type 2, when the subject is still under technical development or where for any
other reason there is the future but not immediate possibility of an agreement on an
International Standard;
-
type 3, when a technical committee has collected data of a different kind from
that which is normally published as an International Standard (“state of the art”, for
example).
Technical Reports of types 1 and 2 are subject to review within three years of publica-
tion, to decide whether they tan be transformed into International Standards.
Technical Reports of type 3 do not necessarily have to be reviewed until the data they
provide are considered to be no longer valid or useful.
ISO/TR 11071-1, which is a Technical Report of type 3, was prepared by Technical
Committee ISO/TC 178, Lifts, escalators, passenger conveyors.
ISO/TR 11071 consists of the following Parts, under the general title Comparison of
worldwide lift sa fe ty s tandards :
-
Part 7 : Electric lifts feleva torsl
- Part 2: Hydraulic lif ts.
ISO/TR 110714 : 1990 (El
Introduction
At the 1981 plenary meeting of ISO/TC 178, work was begun on a comparison of CEN
Standard EN 81/1 with the American, Canad’an, and USSR safety Codes. In 1983, Working
Group 4 was officially formed to carry out the task of preparing a Cross reference between
the relevant sections of these Standards and to analyze the differentes on selected subjects.
The goal at that time was to prepare a technical report which would provide reference
information to assist national committees when reviewing and revising individual Standards
which may initiate a gradual convergence of the technical requirements. In 1984, the study
was expanded to include the CMEA safety Standard.
The content of this report is based on the information provided by the WG 4 members.
The information which could not be obtained on the CMEA Standard at the time of
publication is noted in the report by a “?” in some of the tables.
This report is intended to aid Standards writers in developing their safety requirements,
and to help Standards users understand the basis for the requirements as they are applied
throughout the world.
This report is not intended to replace existing safety Standards. Conclusions are arrived
at in some cases, but only where there is unanimity amongst the various experts. In other
cases, the reasons for the divergent views are expressed.
This report must be read in conjunction with the various safety Standards, as it was often
necessary to summarize the requirements for the sake of clarifying the comparisons.
Further, the information contained in this report does not necessarily represent the opinions
of the Standards writing organizations responsible for the development of the safety
Standards which are being compared, and they should be consulted regarding
interpretations of their requirements (see Annex B).
.
iv
ISO 11071-1 : 1990 (E)
TECHNICAL REPORT
Comparison of worldwide lift safety Standards -
Part 1:
Electric lifts (elevators)
1 scope 2 Terminology
2.1 Lifts and elevators
This Technical Report consists of a comparison of
the requirements of selected topics as covered by
the following worldwide safety Standards 2.1 .l The term /ri51 as used in the CEN Standard
(and in USSR .Code, as written in the Russian
(excluding regional or national deviations):
language) is referred to as e/evatur in ASME and
CSA Standards and in the English translation of
CEN -- European Standard EN81: Part 1, Lifts
a)
These terms are used inter-
and Service Lifts [Edition 1985 - as presented USSR Code.
changeably in this report.
in BS5655:Part 1: 1986 (excluding national
Appendix)]
ASME -- ASME/ANSI A17.1 Safety Code for 2.1.2 For the purposes of this report, unless
b)
Elevators and Escalators (Edition 1987 otherwise specified, the term wssenger /iW and
including the Al 7.1 a-l 988 and Al 7.1 b-l 989 freight /fi correspond to the following terms used
addenda) in other Standards:
CSA -- CSA Standard CAN3-B44 Safety Code
C)
for Elevators (Edition 1985, including 1
Correspond to terms used in the
Supplement l-1 987)
Terms used in follouing standards*
this report
USSR - USSR Elevator Design and Safe
d)
CEN
Operation Code (Edition NEDRA, 1971 as
t
presented in English Version NEDRA 1972) Passenger Lift except Passenger Passenger
+
lift non-comner- elevator +
cial Freight Passenger
CMEA -- Elevator Safety Regulations of the
e)
vehicle elevator
freight
Council for Mutual Economic Assistance
lift permi tted elevator
to carry
This report applies to electric traction lifts only,
passengers
although some sections may also be applicable
t
1 Freight bion-comer- Freight Attendant 1
for positive drive lifts and other lifts suspended by
Lift”” cial elevator operated
rope or chain.
vehic)e
freight
lift with elevator
lt should be noted that in addition to the above
instructed
I I
listed Standards, lifts must conform to the
users**
requirements of other Standards covering
mechanical, structural, and electrical equipment.

Page 2
Comparison of Lift Safety Standards: Part 1
*See the definitions in the applicable Standards
3 Basis for lift safety Standards
**This term is used only to enable comparisons
development (basic assumptions)
to be made later in this report. It does not
indicate recognition of the term Ifreight liftll
by CEN
3.1 Historical background
3.1 .l All lift safety Standards assume certain
things as being true, without proving them as
2.2 Electrical safety devices and electrical such, and stipulate safety rules that are based on
protecttve devices these assumptions.
3.1.2 No Standard, however, clearly spells out the
I
assumptions used The CEN commitaee analyzed
Correspond to terms used in the
its Standard and summarized in the document
Terms used in following Standards:
CEN/TClO/GTl Nl44E (see Annex C) the
this report p
assumptions that, in the opinion of the committee,
USSR
CEN ASME CSA
l
were used In the CEN Standard.
Electrical Electrical Electrical Electrical
1 saf ety safety protective protective
Idevice devi ce device 1
1 devi ce
3.1.3 The CEN assumptions were compared with
assumptions implicitly built into other safety
Standards. It has been indicated that:
a) Some assumptions apparently used in the
CEN Standard were not listed in the document
referred to in CEN/TClO/GTl N144E;
2.3 Safety gear and safeties
b) Some assumptions used in other Standards
differ from those in CEN/TClO/GTl N144E;
The term s&evgeraras used in the CEN Standard
and
is referred to as safeties in ASME and CSA
Standards. The corresponding term in the English
c) Some things assumed in all Standards as
translation of the USSR Code is safety gews
being true have been proven as being false,
(Sareties). The first two are used interchangeably
such as the possibility of overspeeding in the
in this report.
up direction as a result of failures not
presently anticipated in existing Standards.
2.4 Other terms
3.1.4 Using CEN/TClO/GTl N144E as a model,
the foilowing list of assumptions has been
The following is a list of additional terminology
developed which could be used as a basis for
where there is a differente between the English
future work on safety Standards.
version of the CEN and USSR Standards and the
ASME and CSA Standards:
3.2 General
CEN ASME & CSA 3.2.1 Listed in 3.3 through 3.13 (except as noted)
USSR
are those things specific to lifts that are assumed
Anti-rebound Compensating Compensating fope
as true, although not yet proven or demonstrated
tension device
device rope tie down
as such, including:
Freight loading level
Docking Operation Truck zone
Operation
Fixings Fastenings Fastenings
a) Functioning and reliability of lift components;
tioistway door
Landing doof Hoistway (of
landing) doof
Human behavior and endurante; and
Mains Main power supply Power Source
b)
Weil tioistway
tioistway
Progressive safety Type B Safeties Gradual retardation
C) Acceptable level of safety and safety margins.
geaf safety geaf
Comparison of Lift Safety Standards: Part 1 Page 3
3.2.2 Where the probability of an occurrence is The USSR Standard permits a greater car-area-
considered highly unlikely, it is considered as not to-load ratio under the fdlowing conditions (see
happening. USSR 4.5.17): (1) an electrical device must
automatically prevent the motor from statting;
(2) “cab over loaded” light Signal must be pro-
3.2.3 Where an occurrence proves that an vided in the car; (3) all lift components must be
assumption is false, it does not necessarily prove designed for static Yuil” rated ioad; and
that all other assumptions are false. (4) safeties, buffers, and guides must be designed
for Yuil” dynamic load.
However, the assumed average weight of a
3.2.4 The assumptions should be subject to
periodic review by Standards writing organizations passenger differs: 75kg (CEN), 72.5kg (CSA),
to ensure their continuing validity -- considering 8Okg (US%), while in ASME it is not specified
accident statistics, as weli as such things as (Prior to Al 7.1a-1985, the assumed weight for
purposes of computing the maximum number of
changes in technologies, public expectations (e.g.
product liability), and human behavior. passenger-s which could be safely transported in
an emergency was 68 kg).
Furthermore, the rated ioad to car platform area
ratio is different for freight /Rs (see definitions in
safe Operation assured to 2.1.2). l
3.3 Assumption 1 --
125% of rated load
CEN (non -commercial vehicle
Safe Operation of lifts is assured for loads ranging
with instructed users)
=g/m*
from 0 to 100% of the rated load. In addition, in
the case of passenger /MS (see 2.1*2), safe ASME/CSA (general freight
Class 44) 244/240 kg/m*
Operation is also assured for an overload of 25%,
(motor vehicle Class B) 146/145 kg/m*
however, it is not necessary to be able to raise
(industrial truck Class C) 244/240 kg/m*
this overload nor to achieve normal Operation
USSR No spec
(rated load Performance).
3.3.1 Rationale for Assumption 1
3.3.2.2 Lii components that are normally
3.3.1 .l All safety Standards limit the car area in
designed to withstand, without permanent
relation to its rated capacity (load and/or number
darnage, overioads greater than 25% (such as
of persons) in Order to minimize the probability of
ropes, guides, sheaves, buffers, disconnect
inadvertent overioading. However, it is re-
switches) are not considered in this comparison.
cognized that the possibility of an overloading of
up to 25% still exists on passenger lifts. To
eliminate any hazard for passengers, safe
Operation must be assured, but not necessarily
3.3.2.3 Table 3.3.2.3 Shows some of the safety
normal Operation.
ruies for lift components or features (as applicable
to passenger lifts) which do not always take into
account the case of car overload of 25%.
3.3.1.2 In the case of freigbt /2Yrs (see 2.1.2), no
overloading is anticipated. It is assumed that
designated attendants and freight handlers will
adhere to instructions posted in cars and will not
overload them.
3.4 Assumption 2 - failure of electrical safety
devices
3.3.2 Assumption 1 as applied In current
The possibility of a faiiure of an eiectrical safety
Standards
device compiying with the requirement(s) of a lift
safety Standard ,is not taken into consideration.
3.3.2.1 The ratio of the rated load to the car
platform area for passenger iifts is equai (+5%) in
Since national safety rules for iifts may be based
all Standards for the range of 320 to 4000 kg, and
on different assumptions (some are iisted beiow),
in that respect, universality of the assumption is
universality of Assumption 2 may be questioned.
achieved.
Comparison of Lii Safety Standards: Part 1
Page 4
Table 3.3.2.3
Comparlson of Components’ Ratings
(Percentage of Rated Load)
~~~
Component CEN ASME CSA USSR CMEA
Rope traction Dynamit: Dynamit: Dynamit: Dynamit: Dynamit:
125% 125% 125% 110%
(9.Notes) (208.2) (3.10.2.2) (7.3.10)
Static:
(200%)
(7.3.9b)
*
Mechanical 125% 125%
110%
brake alone (12.4.2.1) (208.8) (3.10.8.2)
(7.3.10)
from rated
Speed
Safety gear** 100% 125% 125% ?
110%
(9.8.1.1) (3.7.4.1)
(205.3) (7.3.10)
*
Holding capacity for 125%. There is no requirement in ASME fot deceieration from any Speed at any load.
** CEN and USSR safety gear is tested in free-fall, ASME and CSA in overspeed with 100% rated load.
3.4.1 Rationale for Assumption 2 3.5 Assumption 3 -- failure of mechanical
devlces
Reliability and safety Performance of iift
components designated as electric safety devices a) With the exception of items listed below, a
is assured if designed in accordance with rules mechanical device built and maintained
contained in a given lift safety Standard. according to good practice and the
requirements of a Standard comprising of
However, the design ruies may be based on
different assumptions. safety rules for iifts, is assumed not to
deteriorate to the Point of creating hazards
before the failure is detected. (Note: National
practices and safety rules may be different,
3.4.2 Assumptlon 2 as applled in current such as safety factors. See Assumption 10.)
Standards
b) The possibility of the following mechanical
Most methods of assuring performante reliability failures shali be taken into consideration:
of eiectrical safety devices are similar in present
Standards. There are, however, differentes and 1) rupture of car Suspension means.
inconsistencies, as detailed in section 12.
2) uncontroiled motion of the iift due to:
Section 12.1.3 deais in particular with
discrepancies in assumptions implied in a) ioss of traction while the car, loaded
requirements for design of electrical safety in accordance with Assumption 1, is
descending, ascending, or stationary;
devices.
Comparison of Lift Safety Standards: Part 1 Page 5
and USSR rules imply that safety gear must be
b) brake failure with car descending,
able to stop, or at least slow down, a free falling
ascending, or stationary;
car.
c) failure of machine components such
as shafts, gearing and bearings with the
352.2 All Standards imply that protection in the
car descending, ascending, or stationary.
case of loss of traction of a stationary or
descending car must be provided. CEN requires
3) rupture and slackening of any connecting
the safety gear to be rated for 100% of rated load,
means such as safety related auxiliary
ropes, chains and belts where the safety while traction and the brake are to be rated for
of normal lift Operation or the Operation of 125%.
a safety related standby component is
dependent on such connections.
3.5.2.3 No Standard addresses a loss sf traction
c) The possibiiity of a car or countetweight while the car is ascending.
striking a buffer at a speed higher than the
buffer’s rating is not taken into consideration.
3.5.2.4 No Standard assumes a failure sf the
d) The possibility of a simultaneous failure of a brake while the car is ascending. CEN alone
mechanical device listed above and another assumes failure of mechanical components of a
mechanicai device provided to ensure safe brake and requires redundancy for such
Operation of a Ht, should the first failure components only (see also 11.1.3).
occur, is not taken into consideration.
3.5.2.5 No Standard assumes a failure of any of
3.5.1 Rationale for Assumption 3 the listed machine components while the car is
ascending.
3.5.1 .l Although recent accident records do not
suppott the assumption in 3.5(b)(l), most safety
Standards (including those studied in the
preparation of this report) still assume that the 3.5.2.6 Standards differ significantly in regard to
risk of Suspension means failure, in particular wire the rupture or slackening of connecting means.
Only CEN seems to be consistent in adopting this
ropes, exists.
assumption. Some Standards are inconsistent,
e.g. ASME [209.24(2)] and CSA (3.11.2.4~)
anticipate failure of tapes, chains or ropes
3.5.1.2 The iist of possible mechanicai faiiures in operating normal terminal stopping devices but
3.5(b)(2) is compiled on the basis of records of they do not anticipate failure of an overspeed
recent accidents, which indicate that the governor rope. Only CEN (9.9.11.3) and USSR
assumptions reiated to the reliabiiity of certain (5.1.27h) assume the possibility of governor rope
mechanical components need continual review failure.
and revision where necessary. in addition, the iist
intends to resolve inconsistencies in assumptions
used in existing Standards.
3.5.2.7 All ‘Standards have adopted the
assumption that the possibiiity of a car or
counterweight striking buffers at a Speed higher
3.5.1.3 With the assumption in 3.5 (b)(3) it is than the buffer’s rating is not taken into
recognized that the listed components could consideration.
deteriorate to the Point of creating a direct or
potential hazard (by making a safety related
standby component inoperative) before the
All Standards have adopted the
deterioration is detected. 3.5.2.8
assumption that the possibility of a simultaneous
failure of a mechanicai device mentioned in
3.5.2 Assumption 3 as applied In current
Assumption 3 and another mechanical device
Standards
provided to ensure safe Operation of a lift, should
the first faiiure occur, is not taken into
3.5.2.1 CEN (9.8.1.1) clearly assumes failure of
consideration.
Suspension means, while ASME (205), CSA (3.7)

Comparison of Lii Safety Standards: Part 1
Page 6
3.6 Assumptlon 4 - lmprudent act by users
3.8 Assumption 6 - car speed llnked to
frequency of malns
A user may in certain cases make one imprudent
act, intentionally made to circumvent the safety
An aiternating current iift motor, connected
function of a lift component without using special
directiy to its mains having constant voitage
tools. However, it is assumed that:
and frequency, will not aiiow the iift to resch a
Speed in excess of 115 % of its rated Speed
a) two imprudent acts by users will not take
whiie the motor’s connections with the power
place simultaneously; and
supply are maintained.
b) an imprudent user’s act and the failure of the
backup component designed to prevent the 3.8.1 Rationale for Assumption 6
safety hazard resuiting from such imprudent
acts will not take place simultaneously (e.g. a This assumption is based on the inherent feature
user manipuiating an intetlock and a safety of an AC squirrei tage motor whose Speed is
circuit failure). determined by the number of poles of its winding
and frequency of its suppiy. The rotating Speed
of the motor may vary up to + 15% from its
synchronous Speed, while it isöperating as a
3.6.1 Assumption 4 as applied in current motor or generator.
Standards
lt would appear that most existing Codes are 3.8.2 Assumption 6 as applied in current
based on this assumption. Standards
CEN uses this assumption [9.9.11.1 (a)], permitting
governor overspeed switches to operate at the
same Speed at which the governor itself trips.
3.7 Assumption 5 - neutralization of safety CSA also uses this assumption (3.8.4.1 .l),
devices durlng servlclng permitting governors without an overspeed switch
on lifts powered by a squirrel tage motor. Other
Codes, however, do not consider this assumption
If a safety device, inaccessible to users, is
deliberately neutralized in the course of servicing to be false.
work, the safe Operation of the lift is no longer
assured.
3.9 Assumption 7 - horizontal forces exerted
by a person
3.7.1 Rationale for Assumptlon 5
One person tan exert either of the following
If a mechanic, while servicing a lift, neutraiizes or horizontal forces at a surface perpendicular to the
plane at which the person Stands:
circumvents a safety device (e.g. bypassing door
interlocks using a jumper cable or readjusting
a) static forte - 300 N
overspeed governor) safe lift Operation cannot be
assured.
b) forte resulting from impact - 1000 N
While it is assumed that MS will be designed to
facilitate ease of servicing work and that Service Static forces of short time duration may be
mechanics will be equipped with adequate exerted by the simuitaneous deiiberate acts of
instructions, tools and expertise to safely Service several People located immediately adjacent to
lifts, it is recognized that “fail-safe” Service work each other at every 300 mm interval along the
width of a surface.
tan never be assured soleiy by the design of a
.
Ilft .
3.9.1 Rationale for Assumption 7
3.7.2 Assumption 5 as applied In existing it is assumed that a person leaning against a
Standards vertical surface will exert these forces at that
surface. It is further assumed that more than one
Most Standards are based on this assumption. person tan exert this forte on a sutface

Comparison of Lift Safety Standards: Part 1 Page 7
Table 3.9.2
Assumption 7 as applied in current Standards
ASME CSA
Assumption CEN USSR CMEA
Static forte
1110 N 2500N
Landing Doors 300 N No spec. No spec.
(2.11.10.4.7)
(7.2.3) [llO.lle(7)]
334N 330 N
Car Enclosure 300 N No spec. No spec.
(204.1~) (3.6.1.3)
(8.3.2.1)
Impact No spec. No spec. 5000 N No spec. No spec.
(2.11.10.5)
Forte No spec. No spec. No spec. No spec. No spec.
distribution
Table 3.10.2
Assumption 8 as applied in current Standards
Assumption CEN ASME CSA USSR CMEA
Average retardation*
Safety gear 1 g ?
lg 19 19
(9.8.4) (205.8b) (3.7.9.2) (4.9.1)
Buff ers No spec. ?
Ql 19 19
(10.4.3.3) (201.4b) (3.3.5.2)
Maximum retardation
Safety gear No spec. No spec. No spec. 2.5 g
2.5 g
duration
0.04 s 0.04 s
(4.7.5) .
(3 3)
Buffers 2.5 g 2.5 g 2.5 g 2.5 g No spec.
duration 0.04 s 0.04 s 0.04 s -0.04 s
(10.4.3.3) (201.4b) (3.3.5.2) (4.0.1)
*
Average retardation levels exceeding 1 g tan occur with a lightly loaded li‘k during safety or buffer
application
Note: 1 g = 9.81 m/s*
Comparison of Lift Safety Standards: Part 1 Page 8
simultaneously. Only by relating a forte to the Phrase “maximum upward travel” which includes
width of a surface on which it tan be exerted, tan the counterweight on its fully compressed buffer,
a realistic design requirement be obtained.
plus any additional movement to take into
account the jump of the car upon counterweight
bufFer engagement. CEN defines the distance
3.9.2 Assumption 7 as applled In current from the position of the car with the
Standards counteyeight on its fully compressed buffer, plus
0.035 V . Wording of the USSR code implies a
See Table 3.9.2. similar requirement. After these distances are
taken into account, the ASME code requires an
additional 1.07 m, CEN 1 m, and USSR 0.75 m.
All of these requirements apply only to a specific
3.10 Assumptlon 8 - retardation area of the car roof intended to be used by
persons performing maintenance or inspection.
A person is capabie of withstanding an aver-
Requirements for clearances from equipment on
age verticai retardation of lg (9,81 m/s2) and
the tops of cars vary significantly between the
higher transient retardations.
Standards (Table Al, item 1.3).
3.10.1 Rationale for assumption 8 The top car clearances, according to CEN, are
measured from the Position of the car when the
The retardation which tan be withstood without countetweight is on its fully compressed buffer,
injury varies from person to person. Historically, while in ASME the clearances are measured with
the values used in the Standards (see table 3.10.2) the car at the top car landing.
have not been shown to be Unsafe for a vast
majority of People.
4.1.4 Jump of car. Both CEN and ASME allow
a reduction in the top of car clearance where
3.10.2 Assumption 8 as applied in current means are provided to limit the jump of the car
Standards upon counterweight buffer engagement (Table Al,
item 1.5a). CEN, however, requires that the
clearance be increased by a value equal to the
See Table 3.102.
possible travel of the compensating sheave
(tensioning pulley) plus 1/500 of the car travel (or
at least 0.2 m) to take rope-stretch into account.
ASME does not include this Provision. The other
Standards do not cover this Situation.
4 Spates and cleatances
4.1.5 Refuge space. There are major dif-
ferences in the requirements for the size and
iocation of the refuge space on the car top (Table
4.1 Historical background
Al, item 3). While ASME requires that one face of
the rectangular block be located on the car roof,
4.1 .l The comparison of requirements in present
CEN and CSA appear to permit the location of
Standards for spaces and ciearances is in Annex
this imaginary block anywhere above the car top
A,Table Al. The following are comments on the
equipment. A CEN interpretation indicates that
discrepancies between the requirements.
the projection of the block on the car roof must
include the working sutface specified in CEN
paragraph 8.13.1. In CSA, it must encompass the
4.1.2 Guided travel of car. While CEN qualifies
centerline of the car or the centerline of the guide
the length of “guided travel of car” (Table Al, item
rails.
1 .l), other Standards use performante ianguage
to specifiy that the car shoes shail not ieave their
guides.
4.1.6 Bottom runby. There is no requirement for
a bottom runby (tabie Al, item 4 in CEN or
CMEA, while the maximum car and countenrveight
4.1.3 Free height above car roof. Require-
runbys are specified in ASME, CSA, and USSR.
ments for the free height above the car roof are
Bottom car runby is defined as “the distance
expressed differentiy in each Standard, but the
between the car buffer striker plate and the
end results are similar. The ASME code uses the

Page 9
Comparison of Lift Safety Standards: Part 1
striking surface of the car buffer when the car lift mechanics (car top, weil, pit, and machine
floor is level with the bottom terminal landing.” room), or equipment and indirectly passengers
(e.g. weil-roof-to-car-guide-shoe clearances).
Bottom counterweight runby is defined as “the
distance between the countervveight buffer striker
plate and the striking surface of the counterweight
4.2.2 The need for various horizontal weil
buffer when the car floor is level with the top
terminal landing.” dearances (lable Al, item 7) should be
re-examined The requirements could be
repiaced with a simple performante requirement
that the movement of the car or counterweight
4.1.7 Pit clearance. The minimum pit clearance
shaii not be obstructed considering their relative
(Tabie Al, item 5.1) varies from 0.5 m (CEN and
displacement caused by wear, tear, deflection
CMEA) to 0.75 m (USSR).
expected by eievator use, or by the design of
their guiding means.
4.1.8 Weil-to-entrance-side clearances. For
weil to entrance-car-side clearances (Table Al,
item 6), there are no major discrepancies between 4.2.3 One expert noted that all of the Standards
although there are minor require enough space on the car top to safely
the Standards,
accommodate only one person. This assumption,
differentes. Some Standards permit cars without
however, is not stated.
doors, and there are also minor differentes in the
requirements here.
4.2.4 Whiie there are differentes in hoistway
running clearances, refuge spaces, etc. between
4.1.9 Horizontal weil clearances. Most
the various Standards, there is no evidente to
Standards specify various minimum horizontal weil
support any contention that these are deficient in
clearances (Table Al, item 7) between the car
providing safety. Further, there would be no
counterweight, and weil enclosure, recognizing
Sound reason to propose a reduction to present
the risk for passengers and equipment if the
numerical values without inviting resistance by
running clearances are not maintained. CEN has
field employees and possible government inter-
omitted most of the requirements except for the
vention.
car-to-counterweight (item 7.2) and the car-to-car
Only USSR limits the
(item 7.6) clearances.
maximum car-to-weil-enclosure and
car-to-counterweight clearances (items 7.1 and
. . 4.3 Point agreed upon
7 2)
4.3.1 If reduction in the car top ciearances is
4.1 .lO Machine room clearances. There are permitted on iifts with tie-down compensation, the
differentes in the requirements for the machine possibiiity of the compensating pulley (sheave)
movement and the rope stretch should be taken
room clearances. Within each Standard, the
clearances also vary depending on the type of into account.
equipment that is located in specific parts of the
machine room.
4.3.2 For consistency with car top refuge space
requirements, all standards should specify
requirements for pit refuge spaces (Table Al, item
5.3), that is presentiy covered only in CEN.
4.2 ObseNations and suggestions by
ind ivid ual experts 4.3.3 Regardless of dearances specified, prudent
designers must also consider construction
4.2.1 The requirements for spaces and tolerantes, effects of loading, and wear to assure
clearances in the Standards are significantly that the movement of the car and countetweight
different in respect to the concept (why a are not affected.
requirement is needed) and the quantity (how
much Zs needed). This is an obvious result of the
4.3.4 Refuge spaces are intended to provide
lack of basic assumptions in respect to the
adequate space on top of or beneath the elevator
acceptable clearances or spaces that should be
car for a person when the car is at the extreme
based on specified minimum safety level for
iimit of travel.
passengers (clearances around the car entrance),

Comparison of Lift Safety Standards: Part 1
Page 10
assemblies induding means used for inter-
5 Door Systems and interlocks
connecting locked and non-iocked paneis.
A Survey carried out by an elevator Company
5.1 Historical background
estimates the number of car Stops per year at
100-200 thousand in residential buildings, 3OO-400
5.1 .l General. Every safety standard recognizes
thousand in office buildings and 600 000 in hotels.
that proper ciosing and locking of landing lift
entrances is of paramount importante for the
If the car Stops at main floor landing once in
safety of iift users.
every 3 to 6 Stops, the locking device at the main
floor would be operated 17 000 to 33 000 times a
Rules are given for door iocking devices, for door
year in a iow traffit apartment building, up to 100
panels, and for the door-panel interconnecting
000 to 200 000 cycles a year in a hotel.
means.
Comparison of requirements in present Standards
for horizontaliy sliding door is in Annex A, Table
5.2 Observatlons and suggestions by
A2 .
lndhrldual experts
5.1.2 Door Panels. Discrepancies in the
5.2.1 The door assemblies strength requirements
requirements for the strength of door panels and
in present Standards should be re-examined. At
their fastenings are significant, ranging from 300 N
least assumption #7 (see 3.9) should be taken
(CEN) to 5000 N (CSA) forces perpendicular to
into consideration.
door panels.
The CSA requirements were introduced after a
5.2.2 The door iock should never be considered
number of persons were fatally injured by falling
apart from the door even in the case of a Single
into the hoistway from a ianding where the door
panei, because the leck attachments to the door
Panel was disiodged when typically two persons
are important for the iocking function.
The
smashed into the door whiie horseplaying in the
“linkage” between a door and its leck, as weil as
hallway. Following a series of tests with a soft
between two door components should be
body of 200 kg impacting in the Center of a
specified in greater details. All linkages should be
typical elevator door panel at a Speed of 10 km/h,
considered as Parts of locking Systems.
reactions were recorded. The corresponding
static forte of 5000 N in the door Center was
established as design criteria. A safety factor sf
5.2.3 Standards should specify minimum
1,5 to 2 is assured with that forte.
engagement of the leck pin before the electrical
contact is ciosed. Further, the Standards should
Since a person wouid not normally exert a forte
prohibit wear of iocking pins during Operation
perpendicular to the door panel, but rather at an
(rubbing between moving and stationary iocking
angle, one component of the forte would tend to
components).
push the door inwards and the other to lift the
door, for that reason an additional design criteria
was added in CSA (Table A2, item 3).
5.2.4 Locking Systems should be tested for
endurante through at least 1 million cycles.
5.1.3 Lacks and Contacts. Electrical
requirements are simiiar. Major differentes:
5.2.5 The number of cydes in the type test
Some Standards do not specify the minimum
shouid vary based on the appiication, type of
engagement of the locking pins (Table A2, item 8)
door System, and frequency of inspection.
and the minimum strength of the locking member,
with a forte applied in the direction of door
opening (item 10). Eiectrical checking of dosing
unlocked panels is required only in CEN and
5.3 Points agreed upon
USSR Standards @em 16).
5.3.1 The door assemblies strength requirements
in most present Standards should be re-examined.
5.1.4 Testing. Major differentes are in the
At least Assumption #7 (see 3.9) should be taken
number of test cycles (Tabie A2, items 20 and 21).
into consideration.
Also, not all Standards require testing of door

Comparison of Lift Safety Standards: Part 1 Page 11
5.3.2 The door leck should never be considered h) Consideration should be given to the
development of rules to regulate the minimum
apart from the door even in the case of a Single
door closing times.
panel, because the leck attachments to the door
The
are important for the locking function.
Performance of a leck should be specified in more i) The veiocity-time curves for the door motion
detail, however, it is not proposed that evety Profile should be as flat as possible.
possible combination of components be
type-tested. j) From an enforcement perspective, it was
desirable to use verifiible criteria which could
be checked in the field.
5.3.3 Standards should specify minimum
engagement of the leck pin before the electrical k) Marking plates which should specify the
contact is closed. Further, even if wear occurs, maximum door closing speed and kinetic
the locking function should not be diminished. energy should be considered.
5.3.4 lt is agreed that the quality of interlocks
must be verified through type testing, however i) During the course of the Al7 study, a Survey
there is no agreement in regard to the number of was made of subway train doors in the NYC
cycles which should be required. The experience Transit System during which it was found that
of countries which use 100 000 cycles does not the subway doors had a 40 Ib Stall forte.
justify an increase to 1 000 000 cycles.
m) Future development should not be impeded
by unrealistic and/or unnecessary Code
limits.
6.1.2 The results of the three-year study by the
6 Kinetic energy
Al7 Technical Subcommittee on Power Door
Operation reaffirmed that two engineering
6.1 Historlcal Background
parameters should continue to be used: kinetic
energy, which addresses the impact of the
6.1.1 In preparation for the post-World War II
moving masses; and the Stall forte, which
major revision to the Al 7.1 Code which was
addresses the potential for crushing a passenger
published in 1955, a Technical Subcommittee on
between doors closing from opposite directions
Power Door Operation was formed in 1952 to
or between doors and the door jambs.
study the subject of power door closing and to
revise the Code requirements as necessary. This
Subcommittee carried out their study, considering
6.1.3 The numerical values of these parameters
the following Points:
have been in the Al 7.1 Code since the 1955
edition. These values have also served as the
The industry trend following World War II was
a)
basis for regulating door Systems within the US
toward “operatorless” elevators.
building industry on power-operated doors un-
related to elevators, such as sliding or swinging
Passenger reaction and behavior really Sets
b)
glass doors. l
the human factor limits.
The impact of the moving door System is
Cl
6.1.4 Table 6.1.4 summarizes the Al 7.1 Code
proportional to the kinetic energy of the
requirements covering the power door closing
moving masses.
Operation of passenger elevators predating the
period when limits were first set and continuing
The industry accident experience was
d)
up to the present day.
relevant.
Prior to the 1931 Version of the Al 7.1. Code, there
Present practice should be considered.
e)
were no requirements relating to power door
closing of passenger elevator doors. However,
Instantaneous kinetic energy values as high
the 1931 Code did specify limits for the door Stall
as 25 ft-Ib were common on elevators having
forte and kinetic energy, recognizing that it was
attendants.
quite common to have power-closed car doors
used in conjunction with manual hoistway doors.
There should be a reduced value of the
CO
A 30 Ib Stall forte limit was specified for the car
kinetic energy where there is no door
doors, and a kinetic energy of 5 ft Ib was allowed
reopening device.
Comparison of Lift Safety Standards: Part 1 Page 12
and 84 in. high. The surface area of the door
for the car door, however, if the car and hoistway
panel including the oerlap at the door jambs was
doors were coupled, the allowable kinetic energy
approximately 25.0 ft . Based upon conventional
was increased 40% to 7 ft Ib. In determining the
door panel construction, i.e., sheet with internal
kinetic energy, an average door closing Speed
stiffeners, car oor panels where assumed to
(v,) across the entire door opening width was
weigh 5.0 Ib/ ; hoistway doors assumed to
taken.
weight 7.0 Ib/ nf . Gar door hangers and hoistway
door hangers were taken as 25.0 Ib per set of
doors.
Table 6.1.4
The summary sf weights were as follows:
Stall Forte (Ib) KE (ft-lb)
125.0 IbCar door
l vav i
175.0 IbHoistway door
C C&H C H C&H Basis
50.0 Ib Hangers & Rollers
(Gar & Hoistway)
10.0 Ib Vanes & Hardware
366.0 IbTotal
An average door closing Speed of 1 .O ft/sec (12.0
in/sec) was used since this was a typical door
closing Speed used in practice. Using the
I
11955 to 1 7.0" ‘Code . conventional kinetic energy equation.
Zone
IPresent
* KE = m-a 1 MV 2 = w-m ' -- (=))(1*")2 ------ ----w-w = 5 6 ft - Ib
Reduced to 2.5 ft lb when no reopening device
2 2 32.2 l
is used .
Notation: C = Cars doors only
Recognizing that the kinetic energy of the entire
H = Hoistway doors only
door System is affected by the rotational kinetic
C+H = Car and hoistway doors
energy of the Operator motor and transmission
(pulley, chains, gearing, arms, etc.), an additional
25% was added. Therefore, the permissible
amount of kinetic energy was established for the
case where the doors were provided with a
6.1.5 With the inclusion of the 1955 requirements
reopening device. In setting the reduced value of
in the A17.1 Code, the focus shifted to the
the kinetic energy where no reopening device is
hoistway doors, or to both the car and hoistway
provided, a 40% reduction to the average Speed
doors if they were coupled. There is an additional
which resulted in 7.0 ft Ib kinetic energy would
subtlety involving the basis for determining the
result in the lower value of 2.5 ft Ib.
average closing Speed of the doors. Prior to the
1955 Code, it was based on the entire door
opening width. In 1955, the average closing
Speed became based upon the “Code zone
6.1.7 While the values for door Stall forte and
distance,” which is slightly less than the entire
kinetic energy based upon the average closing
The Al 7.1 Technical
door opening.
speed tan be related to the most common size
Subcommittee on Power Door Operation decided
doors used at the time, there is no documentation
that it was best to
during their 1953 study
available that Shows any correlation to acceptable
travel at t he Start of
discount the slow door
levels of
...