UL 1655 standard pdf

11.5 Class I and II Locations – Main poles and interpoles of D.C. motors

11.5.1 General

11.5.1.1 (I, II) A d-c motor for Class I, Group D, and Class II locations, with the main poles and interpoles fastened to the stator frame by bolts or studs, shall have a distance from the edge of the pole piece to the bolt hole in the motor frame of not less than 3.2 mm (1/8 inch) if the diametrical clearance between the bolt and bolt hole is not more than 0.58 mm (0.023 inch) for a distance of not less than 12.7 mm (1/2 inch) of the unthreaded bolt shank.

11.5.1.2 (I, II) The pole piece shall be tightly clamped against the interior of the motor frame with a clearance of not more than 0.10 mm (0.004 inch).

11.5.1.3 (I, II) A lock washer may be used with the bolt. Metal shims may be provided in the joint between a pole piece and the stator frame.

11.5.2 Brush holders

11.5.2.1 (I, II) A cap of a brush holder shall be provided with metal threads for engaging a metal brush holder mounted through the wall of the motor enclosure.

11.5.2.2 (I, II) For a motor for Class I locations the number and size of engaged threads shall be as specified in Table 7, and shall have a minimum length of thread-engagement of not less than 7.9 mm (5/16 inch).

11.5.2.3 (I, II) For a motor for Class II locations, there shall be at least 3 full threads engaged, and the threads shall not be finer than 25 per 25.4 mm (1 inch).

11.5.2.4 (I, II) The insulation provided between the brush holder and the enclosure, and on the brush-holder cap, shall be phenolic composition or the equivalent, and there shall be no exposed live parts. The joints between portions of a brush-holder assembly and between the assembly and the motor enclosure shall comply with the requirements specified for joints in the motor enclosure.

12 Holes in Enclosure

12.1 (I, II) Other than as noted in 12.5, a hole in an enclosure for securing a part, such as a nameplate or a switch, shall be bottomed.

12.2 (I) The remaining thickness at the bottomed hole shall be sufficient to withstand the internal explosion pressures as shown by calculations or by an over pressure test.

12.3 (I) Fastenings such as removable bolts, screws, and studs, shall not leave an opening in the enclosure wall when omitted. The minimum thickness of metal around the hole shall be not less than 3 mm (1/8 inch) or 1/3 of the diameter of the hole, whichever is greater. The minimum thickness of metal at the bottom of the hole shall be not less than 3 mm (1/8 inch) or 1/3 of the untapped diameter, whichever is greater.

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UL 2218 standard

S6S2-11

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17.9.2.2 Radial compression

The buckling stress, Fc, for a radially loaded tube, with circumferential stiffeners spaced at a distance a apart, shall be obtained from Clause 17.11.2.3 using the limiting stress, Fo = Fy, and the appropriate value of the slenderness, [f06c], taken from one of the following formulas:

(c) for long curved elements supported on straight longitudinal boundaries,

(i) when b/R > [f070], then the following shall be used:

(ii) when b/R < [f070], then the following shall be used:

(a) when

3 3

then the following shall be used:

a R R t R
t

/ . / ,
>

6 l

=

(b) when

a R R t / . / ,

.

<

3 3

then the following shall be used:

3 3 l

a t

=

4

R t

l = 6R t

3 3

.

R t

l =

[239b]
[239d][239c] [239e]

2

2 0 1

R b

[23a0][239f] -

.

17.10 Tension members

17.10.1 Limiting slenderness for tension members

Where the proportions of a tension member are to be limited to avoid excessive deflection under incidental lateral loads and vibrations, the following limit shall be observed:

KL r

< +

250 1

f Fe

where

K = effective length factor (see Table 17.4)

r = radius of gyration, mm

f = minimum permanent tension stress, MPa

For members subjected to wind, see Clause 17.11.1.

17.10.2 Shear lag effect

17.10.2.1 General

Where tension is transmitted by fasteners or welds to some but not all of the cross-sectional elements of the member, the reduced effective net area, A’ne , for the member (consisting of angles, channels, tees, zees, and I-shaped sections) shall be determined from Clauses 17.10.2.2 to 17.10.2.4.

F E

e = pl22

758

October 2011

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UL 61800-5-1 standard

© Canadian Standards Association

13.10.18.4 Automatic sequence control

For non-emergency automatic sequence control, it shall be possible for the operator to initiate each interlocked function in sequence by one movement of a push button or selector switch.

Note: The steps in such a sequence may include

(a) actuate traffic signals;

(b) actuate approach gates;

(c) actuate exit gates;

(d) actuate barriers or retarders;

(e) pull span locks;

(f) release brakes;

(g) open span by manually accelerating and decelerating span-driving motors; and

(h) set brakes.

For emergency control, actions by the operator can include operation of bypass switches, selection of the emergency mode of span operation, and skew correction.

Span motor controls shall include all components needed to provide motor protection against abnormal conditions, automatic controlled acceleration and deceleration, modulated speed control (where applicable) (e.g., tower drives without power-synchronizing motors) and four-quadrant control to accommodate overhauling loads involving negative torque or regenerative braking loads, and any other feature needed to ensure satisfactory performance following a single movement of the initiating control switch.

Motor and machinery brake types, and control arrangements, shall be selected so as to ensure time-sequenced brake application under all conditions.

Two modes of stopping span movement shall be provided for variable-speed motor controls, as follows:

(a) normal stop, with controlled electrical deceleration followed by brake application; and

(b) immediate power cut-off and application of brakes initiated by an emergency stop button.

Limit switch, resolver, or encoder actions shall initiate deceleration before the nearly open and nearly closed span positions are reached and the control system shall be designed to accomplish a reduction to slow speed when those positions are passed. Speed limit switches or some other means shall be provided to detect span speed at the nearly open and nearly closed positions. If the span speed is within the normal limit of the span, movement shall continue to completion; if not, power shall be cut off, brakes shall be applied, and a reset operation of the overspeed circuit shall be required before span movement can be resumed. During final seating, the motor torque shall be reduced and the brakes shall remain in released position until the span is tightly seated, after which the brakes shall set and the motors shall be disconnected.

Tower-drive lift bridges arranged for automatic sequence control shall have two independent skew limit switches, resolvers, or encoders connected in series for each span mode of operation.

13.10.19 Speed control for span-driving motors

Multi-speed (stepped) motor controls shall provide at least six steps of acceleration. These steps shall be such that (a) the motor torque will differ as little as practicable from the average torque required for uniform acceleration from zero speed to full speed; and (b) the bridge shall accelerate and decelerate smoothly (i) under the lowest friction conditions in the absence of wind or other extraneous unbalanced loads; and

(ii) when the motors are carrying their maximum loads.

Separate resistors shall be provided for each motor.

Variable-speed (stepless) drives shall provide smooth variable-speed control with a minimum speed range of 10 to 1, independent acceleration and deceleration ramps field adjustable from 2 to 20 s minimum, speed regulation of ±1.5% (or better), and motor slip. Variable-speed motor controls shall also provide four-quadrant control to accommodate overhauling loads, provide dynamic braking, and enable compatibility with programmable controllers.

November 2006

Canadian Highway Bridge Design Code

627

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S6S2-11

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17.25.4.4 Submissions

Welding procedure specifications, data sheets, and repair procedures that have been accepted by the Canadian Welding Bureau shall be submitted to the Owner in compliance with the Plans.

17.25.4.5 Certification of fabrication companies

Any company undertaking welded fabrication in accordance with this Section shall be certified to Division 1 or 2 of CSA W47.2.

17.25.4.6 Web to flange fillet welds

Where practicable, web to flange fillet welds shall be made continuously by mechanized or automatic welding. Welds may be repaired using either a semi-automatic or manual process, but the repaired weld shall blend smoothly with the adjacent welds.

17.25.5 Bolted construction

17.25.5.1 Assembly

When assembled, all joint surfaces, including those adjacent to bolt heads, nuts, and washers, shall be free from loose scale, burrs, dirt, and foreign material that would prevent the solid seating of the parts.

17.25.5.2 Installation of bolts

Only pretensioned ASTM A325 bolts shall be used in slip-critical joints.

17.25.5.3 Turn-of-nut tightening

After the holes in a joint are aligned, a sufficient number of bolts shall be placed and brought to a snugtight condition to ensure that the parts of the joint are brought into full contact with each other.

Following the initial snugging operation, bolts shall be placed in any remaining open holes and brought to snug-tightness. Re-snugging can be necessary in large joints. Two washers are to be used, one under head face and one under nut face.

When all bolts are snug-tight, each bolt in the joint shall be further tightened by the applicable amount of relative rotation specified in Table 17.11 with tightening progressing systematically from the most rigid part of the joint to its free edges. During this operation, there shall be no rotation of the part not turned by the wrench unless the bolt and nut are match-marked to enable the amount of relative rotation to be determined.

Table 17.11
Nut rotation from snug-tight condition* (See Clauses 17.25.5.3 and 17.25.5.4.)

Disposition of outer faces of bolted parts

Bolt length†

Turn from snug

Both faces normal to the bolt axis or one face normal to the axis and the other sloped 1:20 (bevelled washers not used)

Up to and including four diameters 1/3

Over four diameters and not exceeding eight diameters or 200 mm

1/2

Exceeding eight diameters or 200 mm 2/3

Both faces sloped 1:20 from normal to the bolt axis (bevelled washers not used)

All lengths

3/4

*Nut rotation is rotation relative to a bolt regardless of whether the nut or bolt is turned. The tolerance on rotation is 30° over. This Table applies to coarse-thread, heavy-hex structural bolts of all sizes and lengths used with heavy-hex semifinished nuts.

†Bolt length is measured from the underside of the head to the extreme end point.

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814

October 2011

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UL 207 standard

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17.25.1.3 Shop details

Shop details shall provide (a) full detail dimensions and sizes of all component parts of the structure. These dimensions shall make allowance for changes in shape due to weld shrinkage, camber, and any other effects that cause finished dimensions to differ from initial dimensions;

(b) all necessary specifications for the materials to be used;

(c) identification of areas requiring special surface treatment;

(d) identification of fracture-critical and primary tension members and component parts;

(e) bolt installation requirements; and

(f) details of all welds.

17.25.1.4 Welding procedures

Welding procedures shall comply with CSA W47.2.

17.25.1.5 Erection procedure drawings and calculations

The erection procedure drawings and calculations shall fully indicate the proposed method of erection, including the sequence of erection, the weights and lifting points of the members, and the location and lifting capacities of the cranes used to lift them. Details of temporary bracing and bents to be used during construction shall be shown. Calculations shall be provided to show that members and supports are not overloaded during erection.

17.25.1.6 Symbols for welding and non-destructive testing

The symbols for welding and non-destructive testing on shop drawings shall be in accordance with CSA W59.2.

17.25.2 Materials

17.25.2.1 Aluminum

Substitution of aluminum members or components for size and alloy shall not be permitted unless Approved. All aluminum shall be new. Acceptance of any material by an inspector shall not preclude subsequent rejection of the material if it is found defective.

17.25.2.2 Bolts, nuts, and washers

Zinc-coated nuts and bolts shall be shipped together as an assembly.

The nuts of coated or plated fasteners shall be over-tapped by the minimum amount required for assembly and shall be lubricated with a lubricant containing a visible dye. The use of a mechanically deposited zinc coating shall require Approval.

17.25.2.3 Electrodes

The supply and storage of filler shall comply with CSA W59.2.

17.25.3 Fabrication

17.25.3.1 Quality of work

The standards for quality of work and finish shall comply with the best modern practices for metal bridge fabrication (with particular attention to the appearance of parts exposed to view).

17.25.3.2 Storage of materials

Plain or fabricated structural aluminum shall be stored above the ground on skids or other supports and kept free from dirt and other foreign matter or exposed to moisture. Long members shall be adequately supported to prevent excessive deflection. Aluminum members shall not be stored in contact with one another if exposed to moisture.

October 2011

Supplement No. 2 to CAN/CSA-S6-06, Canadian Highway Bridge Design Code

811

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13.8.17.4 Plain bearings

13.8.17.4.1 Proportions

The length of a bearing shall not be less than the diameter of the journal and should be 1.5 times that diameter except for counterweight sheaves, where the length shall not be more than 1.2 times the diameter.

13.8.17.4.2 Adjustment

On all bearings, adjustment for height shall be provided in order to allow for wear. Adjustment of caps by means of laminated brass liners shall be provided.

13.8.17.4.3 Bushings

Bearings shall have bronze bushings unless otherwise approved by the Engineer. Alloys for various types of service shall be in accordance with Table 13.12.

The bronze linings shall be effectively locked against rotation. The force tending to cause rotation shall be taken as 0.06 times the load on the bearing, acting at the outer radius of the lining.

The inside corners of the bushings shall be rounded or chamfered, except for a distance of 10 mm from any joint.

13.8.17.4.4 Journal bearings

Journal bearings shall have split housings. The cap shall be recessed into the base and fastened by bolts, with the heads recessed into the base. Nuts shall be hexagonal and lock nuts shall be provided.

Both heads and nuts shall bear on finished bosses or spot-faced seats. Bearings shall be designed to facilitate cleaning.

13.8.17.4.5 Step bearings

The bearing ends of vertical shafts running in step bearings shall be of hardened steel and shall run on bronze discs.

13.8.17.5 Anti-friction bearings

13.8.17.5.1 General

Anti-friction bearings may be used for applications where good commercial practice would indicate their suitability and economy.

Anti-friction bearings shall be sized for an American Bearing Manufacturers Association B-10 life of 40 000 h under design running conditions.

Anti-friction bearings mounted in pillow blocks shall be self-aligning and shall have seals suitable for the conditions under which they operate. Housings shall be steel and may be split on the centreline. Bases shall be solid and shall be drilled for mounting bolts at assembly. Positive alignment shall be provided between the cap and the base on split housings. The alignment system shall be adequate for the design bearing loads.

13.8.17.5.2 Thrust bearings

The bearing ends of vertical shafts shall run in ball or roller thrust bearings or in radial bearings of types capable of carrying both radial and thrust loads.

13.8.17.5.3 Trunnion bearings

Where roller bearings are used to support the trunnions of counterweight sheaves of vertical lift bridges and similar shafts carrying heavy loads, they shall receive special design consideration in establishing the most suitable size and type. Only manufacturers who have experience in producing bearings for this type of service shall be considered.

November 2006

� Canadian Standards Association

610

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UL 19 standard

CAN/CSA-S6-06

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Overfill zone
(soil group I, II, or III)

H

Excavation line, as required

Do/6 (min.)

Do

Do/3

Do (min.)

Haunch zone

This in-situ soil shall be considered as lower sidefill zone for the calculation of
soil properties

Middle bedding zone loosely placed uncompacted granular, except Type 4

Di

Bedding

Outer bedding zone material and compaction each side — same requirements as haunch

Foundation

Figure 7.9
Terminology and standard installations for circular precast concrete pipes in trenches (See Clauses 7.2, 7.8.3.5.1, 7.8.3.5.2, and 7.8.15.6.1.)

282

November 2006

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Table 17.8 (Continued)

General condition Situation

Detail category Illustrative example (see
Figure 17.4)

12

Transversely loaded groove-welded attachments with weld soundness established by non-destructive testing and all required grinding transverse to the direction of stress Base metal at detail attached by full-penetration groove welds with a transition radius, R, as follows: (a) to flange, with equal plate thickness and weld reinforcement removed:

(i) R [f0b3] 600 mm;

(ii) 600 mm > R [f0b3] 150 mm;

(iii) 150 mm > R [f0b3] 50 mm; or

(iv) R < 50 mm;

(b) to flange, with equal plate thickness and weld reinforcement not removed or to web:

(i) R [f0b3] 150 mm;

(ii) 150 mm > R [f0b3] 50 mm; or

(iii) R < 50 mm;

(c) to flange, with unequal plate thickness and weld reinforcement removed:

(i) R [f0b3] 50 mm; or

(ii) R < 50 mm.

B

C

D

E

C

D

E

D

E

Fillet-welded connections with welds normal to the direction of stress Base metal, as follows: (a) at details other than transverse stiffener to flange or transverse stiffener to web connections; and (b) at the toe of transverse stiffener to flange and transverse stiffener to web welds.

E

C

19

6

E 16

Fillet-welded connections with welds normal and/or parallel to the direction of stress Shear stress on the weld throat

Longitudinally loaded fillet-welded attachments Base metal at details attached by fillet welds, as follows: (a) when the detail length in the direction of applied stress is (i) less than 50 mm;

(ii) between 50 mm and 12 times the detail thickness, but less than 100 mm; or (iii) greater than either 12 times the detail thickness or 100 mm: (1) detail thickness < 25 mm; or (2) detail thickness [f0b3] 25 mm; and (b) with a transition radius, R, with the ends of welds ground smooth, regardless of detail length:

(i) R [f0b3] 50 mm; or

(ii) R < 50 mm.

C

D

E E

D

E

13, 15,18, 20 18, 20

7, 16, 18, 20

12

Transversely loaded fillet-welded attachments with welds parallel to the direction of primary stress Base metal at details attached by fillet welds

E 12

(Continued)

792

October 2011

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Supplement No. 1 to CAN/CSA-S6-06, Canadian Highway Bridge Design Code

16.8 Concrete beams and slabs

16.8.1 General

Except as specified in this Section, the resistance and deformations of concrete beams, slabs, and deck slabs reinforced with FRP tendons, bars, or grids, corresponding to the various limit states, shall be calculated in accordance with Section 8.

The resistance at ULS for beams and slabs with FRP bars or grids in multiple layers shall be calculated by taking account of the linear variation of strain through the depth of the member, ensuring that the stresses in the reinforcement are consistent with Clause 16.8.3.

The maximum compressive concrete strains in beams and slabs due to factored loads shall not exceed the limiting strain specified in Section 8.

Internally restrained deck slabs shall be designed in accordance with Clause 16.8.8.

16.8.2 Deformability and minimum reinforcement

16.8.2.1 Design for deformability

For concrete components reinforced with FRP bars or grids, the overall performance factor, J, shall be at least 4.0 for rectangular sections and 6.0 for T-sections, with J calculated as follows:

J M M

= y y

ult ult c c

where

Mult = ultimate moment capacity of the section
[f079]ult = curvature at Mult
Mc = moment corresponding to a maximum compressive concrete strain in the section of 0.001 [f079]

c = curvature at Mc

16.8.2.2 Minimum flexural resistance

The factored resistance, Mr, shall be at least 50% greater than the cracking moment, Mcr, as specified in Clause 8.8.4.4. This requirement may be waived if the factored resistance, Mr, is at least 50% greater than the factored moment, Mf. If the ULS design of the section is governed by FRP rupture, Mr shall be greater than 1.5Mf.

The principles for calculating Mcr and Mr shall be consistent with those specified in Clause 8.8, except that stresses in FRP bars at different levels, if present, shall be calculated by assuming a linear distribution.

16.8.2.3 Crack-control reinforcement

When the maximum tensile strain in FRP reinforcement under full service loads exceeds 0.0015, cross-sections of the component in maximum positive and negative moment regions shall be proportioned in such a way that the crack width does not exceed 0.5 mm for members subject to aggressive environments and 0.7 mm for other members, with the crack width calculated as follows:

w f E h
h k d s

=

2

2 2 /

cr

FRP

FRP

2

1

b c

+ ( )

2

The value of kb shall be determined experimentally, but in the absence of test data may be taken as 0.8 for sand-coated and 1.0 for deformed FRP bars. In calculating dc, the clear cover shall not be taken greater than 50 mm.

May 2010

(Replaces p. 711, November 2006)

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711

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