Clearances - hdbk109220040101

DOE-HDBK-1092-2004

6.2.5

CLEARANCES

In the direction of live parts, the working space clearance is 2 feet, and doors enclosing live

parts that may require service or maintenance shall open at least 90 degrees or be removable.

6.2.6

OSHA AND NEC REQUIREMENTS

29 CFR 1910.179 and NEC Article 610, Part F, provide additional electrical requirements

derived from ANSI and other standards. Significant requirements are the following:

1. Control circuit voltage shall not exceed 600 Vac or dc. Pendant pushbutton voltage shall not

exceed 150 Vac or 300 Vdc.

2. Support shall be provided for pendant multiconductor cables.

3. Electrical systems for cranes and hoists shall provide failsafe operation. When power fails,

all motors shall be automatically disconnected so that they will not resume operation when

the power comes back on. Automatic cranes shall not commence motion automatically when

the power comes on after an outage. Pendant pushbuttons shall be returned to the off

position when pressure is released. When the signal from a remote controller fails, all motion

shall stop.

6.2.7

MAINTENANCE AND OPERATIONS

It is important to have a comprehensive electrical maintenance program for cranes and hoists.

Every electrical part and circuit plays a critical operational safety role and must be checked and

serviced at the frequency and in the manner specified by OSHA, CMAA, ANSI, and the

manufacturer's manual. Required weekly, monthly, and semiannual tests and required

recordkeeping are contained in ANSI B-30 and CMAA documents.

The basic references for safe operation and maintenance of cranes and hoists are contained in

sections of 29 CFR 1910 and 1926.

6.2.8

DOCUMENTED MAINTENANCE

Maintenance checklists and schedules in compliance with OSHA, owner's manuals, and

manufacturer's requirements for the specific equipment shall be provided as required. Weekly,

monthly, and semiannual inspections shall be conducted, and comments and condition of the

inspected part shall be documented and certified.

The recommended frequencies of inspections vary in accordance with application, usage, and

authority. Frequent inspection and periodic inspection are defined by OSHA as daily to monthly

and 1 to 12 months, respectively. Typical inspection frequencies for electrical equipment of

cranes and hoists are as follows:

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