NEC_2014_Article_610_Cranes_and_Hoists.pdf

HMI CONSENSUS

NATIONAL ELECTRICAL CODE –2014

HMI’s GOAL IN DEVELOPING THIS CONSENSUS

The 2014 National Electrical Code has a number of paragraphs affecting electric chain and wire rope hoists. Some of these paragraphs are subject to varying interpretations.

Therefore, acting through the electrical engineering subcommittee of the HMI engineering committee and with the approval of the HMI Board of Directors, the Hoist Manufacturers Institute has developed and authorized the publication of the consensus contained within this pamphlet. It is hoped that this HMI Consensus will be mutually helpful to users, manufacturers and sellers of electric chain and wire rope hoists. For specific commentary with respect to individual brand hoists, users and sellers should contact the manufacturer(s) of their electric chain and wire rope hoist(s).

GENERAL

Article 100 Definitions

BRANCH CIRCUIT – The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).

FEEDER – All circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device.

IN SIGHT FROM-Where the code specifies that one equipment shall be “in sight from”, “within sight from”, or “within sight of”, and so forth, another equipment, the specified equipment is to be visible and not more than 15m (50ft) distant from the other.

OVERLOAD – Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated amapcity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload.

READILY ACCESSIBLE – Capable of being reached quickly for operation, renewal, or inspections, without requiring those to whom ready access is requisite to climb over or remove obstacles or resort to portable ladders, and so forth.

Article 110

Requirements for Electrical Installations

Section 110.25 – Lockable Disconnecting Means:

Where a disconnecting means is required to be lockable open elsewhere in this Code, it shall be capable of being locked in the open position. The provisions for locking shall remain in place with or without the lock installed.

Article 240

Overcurrent Protection

Section 240.1 – Informational Note: Overcurrent protection for conductors and equipment is provided to open the circuit if the current reaches a value that will cause an excessive or dangerous temperature in conductors or conductor insulation.

Article 430 Motors, Motor Circuits, and Controllers

Part I. General

Section 430.1 - Covers motors, motor branch circuit and feeder conductors and their protection, motor overload protection, motor control circuits, motor controllers, and motor control centers.

Part III. Motor and Branch-Circuit Overload Protection

Section 430.31 - Part III specifies overload devices intended to protect motors, motor-control apparatus, and motor branch-circuit conductors against excessive heating due to motor overloads and failure to start.

NOTE: For the means of protecting against overload, see Sections 430.32, 430.33, 430.40, 430.72 and 610.43.

Part IV. Motor Branch-Circuit Short-Circuit

And Ground Fault Protection

Section 430.51 - Part IV specifies devices intended to protect the motor branch-circuit conductors, the motor control apparatus and the motors against overcurrent due to short circuits or ground faults.

Part VI. Motor Control Circuits

Section 430.71 - Part VI contains modifications of the general requirements and applies to the particular conditions of the motor control circuit.

Part VII. Motor Controllers

Section 430.81 - Part VII is intended to require suitable controllers for all motors.

Part IX. Disconnecting Means

Section 430.101 - Part IX is intended to require disconnecting means capable of disconnecting motors and controllers form the circuit.

Section 430.109 - The disconnecting means shall be a type specified in 430.109(A), unless otherwise permitted in 430.109(B) through (G), under the conditions specified.

Article 610 Cranes and Hoists

Section 610.1 - This article covers the installation of electrical equipment used in conjunction with crane, monorail hoists, hoists, and all runways.

Section 610.2 - Festoon Cable: Single and multiple conductor cable intended for use and installation in accordance with Article 610 where flexibility is required.

Informational Note: Festoon cable consists of one or more insulated conductors cabled together with an overall jacket. It is rated 60°C (140°F), 75°C (167°F), 90°C (194°F), or 105°C (221°F) and 600V.

HMI CONSENSUS

NATIONAL ELECTRICAL CODE – 2014

Part II. Wiring

Section 610.13 - Conductors shall comply with Table 310.104(A) unless otherwise permitted in 610.13(A) through (D).

Section 610.14 - Ratings and size of conductors.

Part IV. Disconnecting Means

Section 610.31 - Runway conductor disconnecting means.

A disconnecting means that has a continuous ampere rating not less than that calculated in 610.14(E) and (F) shall be provided between the runway contact conductors and the power supply. The disconnecting means shall comply with

430.109. The disconnecting means shall meet conditions (1)

through (4) unless installation meets the exceptions (1) or (2).

Note condition (2): lockable open in accordance with 110.25, and condition (4) Placed (Disconnect) within view of the runway contact conductors. (see definition “in sight from”).

Section 630.32 - Disconnecting means for cranes and monorail hoists. (Note exceptions (2) through (3).) Where a discontenting means is present it must comply with 430.109 and 110.25.

Part V. Overcurrent Protection

Section 630.41 - Feeders, runway conductors.

Section 630.42 - Branch circuit short circuit and ground fault protection.

Branch circuits shall be protected in accordance with 610.12(A). Branch circuit taps, where made shall comply with 610.42(B).

Section 610.43 - Overload protection

CIRCUITS REQUIRED

1. A single hoist either lug, hook or base mounted in a fixed location, i.e., not part of an overhead crane or other traveling member. Refer to circuit A on page 4.

A. Branch Circuit Disconnecting Means (B.C.D.M.)

B. Branch Circuit Overcurrent Protection (B.C.O.P.)

C. Motor Overload Protection (M.O.L.P.) Optional.

See Notes 1 & 2.

2. Two or more individual hoists either lug, hook or base mounted in a fixed location as in 1 above. Circuit B is acceptable in all situations and preferred over Circuit C, which may be used if the requirements of 430.53 are met.

2.1 Preferable for all conditions. Refer to circuit B on page 4.

A. Branch Circuit Disconnecting Means (B.C.D.M.)

B. Branch Circuit Overcurrent Protection (B.C.O.P.)

C. Motor Overload Protection (M.O.L.P.) Optional.

2.2 Refer to circuit C on page 4.

A. Branch Circuit Disconnection Means (B.C.D.M.)

B. Branch Circuit Overcurrent Protection (B.C.O.P.)

C. Motor Overload protection (M.O.L.P.) Optional.

Optional or mandatory - see Note 4.

See Notes 3 and 4 on use of Single Disconnect.

3. A single monorail hoist with plain, hand geared or motorized trolley. If only a plain or hand geared trolley is used omit those items feeding only the trolley motor.

Refer to Circuit D on page 4.

A. Runway Conductor Disconnecting Means (R.C.D.M.)

B. Runway Conductor Overcurrent Protection (R.C.O.P.)

C. Branch Circuit Disconnecting Means (B.C.D.M.)

See Note 5.

D. Branch Circuit Overcurrent Protection (B.C.O.P.)

See Note 4.

E. Motor Overload Protection (M.O.L.P.)

Optional See Note 4.

4. Two or more plain, hand geared or motorized trolley mounted hoists on same runway. If a plain or hand geared trolley is used omit those items feeding only the trolley motor. Refer to Circuit E. on page 4.

A. Runway Conductor Disconnecting Means (R.C.D.M.)

B. Runway Conductor Overcurrent Protection (R.C.O.P.)

C. Branch Circuit Overcurrent Protection (B.C.O.P.)

See Note 5.

D. Branch Circuit Overcurrent Protection (B.C.O.P.)

E. Motor Overload Protection (M.O.L.P.)

Optional See Note 2.

5. Overhead cranes, single or two motor hoists for use on any bridge crane with bridge either hand propelled or motorized. Refer to Circuit F page 4.

See CMAA Consensus.