Crane Electrical System Inspection: Limit Switches, LMI/RCI, Anti-Two-Block & Controls

Electrical system failures account for a significant percentage of crane incidents reported to OSHA each year. Unlike structural deficiencies that often develop gradually and produce visible warning signs, electrical failures can be sudden and invisible. A limit switch that fails to activate, an anti-two-block device with a corroded contact, or a load moment indicator displaying inaccurate readings — any of these can turn a routine lift into a disaster without warning.

Whether you are performing a daily crane inspection or conducting a comprehensive annual crane inspection, the electrical system demands meticulous attention. OSHA's crane standards under 29 CFR 1926 Subpart CC and ASME B30 standards both require that electrical safety devices be inspected, tested, and maintained at defined intervals. This article provides a detailed, component-by-component guide to crane electrical system inspection.

Overview of Crane Electrical Systems

Before diving into individual components, it helps to understand the architecture of a typical crane electrical system. Every crane — whether it is a mobile hydraulic crane, a lattice boom crawler, a tower crane, or an overhead bridge crane — relies on electrical circuits for power distribution, motor control, and safety device operation. The complexity varies by crane type, but the fundamental principles and inspection requirements are consistent.

Power Distribution

Power enters the crane system through one of several pathways depending on the crane type. Mobile cranes typically use engine-driven generators or alternators that produce both AC and DC power for different subsystems. Tower cranes receive power from the site's electrical distribution system through a main disconnect switch at the base. Overhead cranes use bus bars, festoon cable systems, or conductor bar assemblies to deliver power along the runway and bridge.

The main power circuit feeds through a master disconnect or main contactor, then branches into motor control circuits for hoist, trolley, bridge travel, and boom functions. Separate low-voltage circuits supply the control system, safety devices, lighting, and communication equipment. Inspectors must understand the power distribution architecture to trace faults and verify that protective devices are correctly sized and positioned.

Control Systems

Crane control systems range from simple relay-based contactors to sophisticated programmable logic controllers (PLCs) with variable frequency drives (VFDs). Older cranes may use drum controllers, resistance starters, and mechanical brakes. Modern cranes increasingly rely on solid-state controllers, regenerative braking, and CAN-bus communication networks. Regardless of the technology generation, the inspection objective remains the same: verify that all control inputs produce the correct outputs, that all protective interlocks function, and that fail-safe behavior operates as designed.

Safety Devices

Safety devices form the most critical layer of the electrical system. These include limit switches (upper hoist, lower hoist, boom angle, travel), anti-two-block devices, load moment indicators, rated capacity indicators, anemometers, overload cutouts, and emergency stop circuits. OSHA 1926.1415 specifically requires that safety devices be inspected as part of each shift inspection and that deficiencies be corrected before use. Under ASME B30.5 and B30.2, any safety device found inoperative requires the crane to be taken out of service until the device is repaired and tested.

Limit Switch Inspection

Limit switches are electromechanical or electronic devices that prevent crane motions from exceeding safe boundaries. They are the first line of defense against over-travel conditions that can cause two-blocking, boom over-the-back, runway collision, or block drop-off. Every crane has multiple limit switches, and every one of them must be tested and verified during inspection.

Upper and Lower Limit Switches

The upper hoist limit switch (also called the upper block limit or hoist limit) prevents the hook block from being raised into the boom tip or sheave assembly — a condition known as two-blocking. OSHA 1926.1416(d)(3) requires that the hoist limiting device be tested at the start of each shift by activating it under controlled conditions. This means the operator must slowly raise the block until the limit switch trips, verify that hoist motion stops, and confirm that the switch resets properly.

During inspection, check the following for upper limit switches:

• The actuator arm, roller, or weight moves freely without binding, corrosion, or mechanical interference
• The switch trips at the correct distance below the boom tip sheaves (typically 24–36 inches, per manufacturer specifications)
• The electrical contacts are clean, properly adjusted, and show no signs of arcing, pitting, or welding
• The wiring to the switch is intact, properly supported, and protected from chafing and environmental damage
• The switch housing is securely mounted and shows no physical damage or moisture intrusion

Lower hoist limit switches prevent the block from being lowered beyond a safe point, which can cause the wire rope to unspool from the drum and lose its dead wraps. Inspect these switches using the same criteria as upper limits. On overhead cranes, the lower limit is especially critical because a block descending below floor level can damage the rope and create a recoil hazard.

Boom Angle Limit Switches

Boom angle limit switches prevent the boom from being raised beyond its maximum safe angle or lowered below its minimum operating angle. On lattice boom cranes, exceeding the maximum boom angle can cause the boom to go “over the back,” resulting in catastrophic structural failure. The minimum angle limit prevents the boom from being lowered to a position where the load moment exceeds the crane's structural capacity.

Inspection of boom angle limits requires:

• Verify that the boom angle indicator reads correctly at multiple known angles (use an inclinometer for comparison)
• Test the high-angle limit by slowly booming up until the switch activates — confirm the cut-off angle matches the manufacturer's specification
• Test the low-angle limit under controlled conditions with no load, verifying the cut-off angle is correct for the current boom configuration
• Inspect the mechanical linkage between the boom and the switch actuator for wear, looseness, and proper calibration
• On cranes with electronic boom angle sensors, verify the sensor output matches the actual boom angle within the manufacturer's specified tolerance (typically ±0.5°)

Travel Limit Switches

Travel limits are found on overhead cranes, gantry cranes, and tower cranes to prevent the bridge, trolley, or slewing mechanism from exceeding its safe range of travel. On overhead cranes, bridge travel limits prevent the crane from running off the end of the runway, while trolley travel limits prevent the trolley from running off the bridge girders.

Tower crane slewing limits restrict rotation to prevent the crane from wrapping its power cable or from swinging into adjacent structures. These limits may be mechanical cam-operated switches, proximity sensors, or encoder-based electronic limits.

During inspection, operate each travel function slowly toward its limit and verify that the switch stops motion at the correct position. Check that the deceleration zone (on cranes equipped with two-stage limits) activates before the final stop limit. Inspect the physical condition of cam tracks, striker plates, and proximity sensor targets for wear and proper alignment.

Testing Procedures for Limit Switches

ASME B30.2 (overhead cranes) and B30.5 (mobile cranes) both require that limit switches be tested under no-load or light-load conditions at the beginning of each shift. The test procedure must follow the crane manufacturer's instructions. A general procedure includes:

• Notify all personnel in the area that limit switch testing is in progress
• Operate the crane function slowly toward the limit in the slowest available speed
• Verify the switch trips and stops the motion
• Release the control and verify the switch resets and normal operation resumes
• If the switch fails to trip, immediately cease operations and tag the crane out of service until repairs are completed
• Document the test result in the shift inspection record, noting pass/fail status and any observations

Anti-Two-Block (A2B) Device Inspection

Two-blocking occurs when the hook block or load ball is raised into contact with the boom tip sheaves, creating a condition where continued hoisting applies the full line pull directly to the boom tip structure. This can snap the wire rope, collapse the boom, or eject the hook block as a projectile. Anti-two-block devices are specifically designed to prevent this catastrophic event.

How A2B Works

An anti-two-block system consists of a sensing element mounted at or near the boom tip and a control module that interrupts crane functions when a two-block condition is imminent. The most common sensing arrangement uses a weighted switch suspended on a lanyard below the boom tip sheaves. When the hook block rises to within a set distance of the boom tip, the block contacts the weight, lifting it and activating the switch. This triggers a warning alarm and, in most systems, automatically stops the hoist-up function and any boom-down function that would shorten the distance between the block and boom tip.

More advanced systems use proximity sensors, laser distance measurement, or LMI-integrated calculations that monitor the geometric relationship between the hook block and boom tip continuously. These electronic systems can provide graduated warnings at multiple threshold distances and disable specific crane functions selectively.

A2B Inspection Criteria

Under OSHA 1926.1416(d)(3), the anti-two-block device must be tested at the start of each shift by activating the device to verify it stops the applicable crane functions. The inspection must verify:

• The weighted switch or sensor is present, properly suspended, and hangs freely without obstruction from rigging, taglines, or other equipment
• The lanyard or suspension cable is not kinked, frayed, or tangled around the hoist line or boom components
• The warning alarm (audible and/or visual) activates before the crane functions are locked out
• The device actually stops hoist-up and any boom-down motion when triggered
• The device resets properly when the two-block condition is relieved (by lowering the block or booming up)
• All electrical connections are secure, weatherproofed, and free of corrosion

A2B Testing Requirements

The shift test should be performed with the boom at or near its anticipated operating angle and configuration. The operator slowly hoists the block upward until the A2B device activates, then verifies all the criteria above. On cranes with multiple boom configurations (main boom, jib, luffing jib), the A2B must be tested for each configuration that will be used during the shift.

For cranes equipped with mobile crane configurations, the A2B test should also verify that the device functions correctly when the boom is telescoped to different lengths, as the geometry changes affect the trigger point. Additionally, confirm that auxiliary A2B devices on whip lines (jib hoist lines) function independently from the main hoist A2B.

Common A2B Failures

A2B devices fail for predictable reasons that inspectors should watch for during every inspection:

• Lanyard damage: The suspension lanyard becomes kinked, corroded, or shortened, preventing the weight from hanging freely and causing nuisance trips or failure to activate at the correct distance
• Switch corrosion: Moisture intrusion into the switch housing corrodes the electrical contacts, causing intermittent operation or complete failure
• Wiring damage: The signal wiring from the boom tip to the control module runs along the boom and is exposed to vibration, flexing, and environmental damage
• Weight loss: The actuating weight falls off or is intentionally removed, completely disabling the system
• Bypassing: Operators or riggers intentionally bypass the A2B system because it creates nuisance trips during certain operations — this is an OSHA violation and must be reported immediately
• Controller relay failure: The relay or solid-state output in the control module fails, meaning the switch activates but the crane functions are not interrupted

Load Moment Indicator (LMI) and Rated Capacity Indicator (RCI)

Load moment indicators and rated capacity indicators are the most sophisticated safety devices on a crane. They continuously calculate the crane's actual load moment and compare it against the rated capacity for the current configuration. When properly calibrated and maintained, these systems prevent overloading — the leading cause of crane tip-overs and structural failures. Refer to your crane load chart documentation for the rated capacity values these systems are calibrated against.

LMI Components and Architecture

A typical LMI system consists of several integrated components:

• Boom length sensor: Measures the current boom length using a cable-reel encoder, laser distance sensor, or pressure-based calculation on telescopic cranes
• Boom angle sensor: An inclinometer or angular encoder mounted on the boom butt section that measures the boom elevation angle
• Load sensor: Typically a load pin or hydraulic pressure transducer at the boom hoist cylinder, hoist rope dead-end, or hook block that measures the actual load on the hook
• Outrigger/counterweight sensors: On mobile cranes, sensors that detect whether outriggers are deployed and to what percentage extension, which determines the applicable load chart
• Central processor: The computer module that receives all sensor inputs, calculates the load moment, compares it to the load chart values stored in memory, and generates the display output and alarm signals
• Display unit: The operator console that shows current load, rated capacity, percentage of rated capacity, boom length, boom angle, radius, and alarm status

LMI Calibration

Calibration is the single most important maintenance activity for LMI systems. An out-of-calibration LMI is worse than no LMI at all because it provides false assurance. ASME B30.5 requires that LMI systems be calibrated in accordance with the LMI manufacturer's procedures, and many manufacturers specify calibration at commissioning, after any repair or component replacement, and at least annually.

During calibration inspection, verify the following:

• The most recent calibration certificate is on file and within its validity period
• Calibration was performed by a technician qualified by the LMI manufacturer
• Test loads used during calibration were of known, certified weight
• The LMI software version matches the crane's current configuration (boom length, jib installation, counterweight)
• The load chart data programmed into the LMI matches the crane manufacturer's published load chart for the specific crane model and serial number
• The system displays accurate values at multiple test points across the operating range

Display and Alarm Functions

The LMI display is the operator's primary source of real-time load information. During inspection, verify:

• The display is clearly visible from the operator's normal seating position under all lighting conditions
• All display segments, pixels, or indicator lamps function correctly (no dead segments or burned-out lamps)
• The audible alarm is loud enough to be heard over normal crane operating noise (typically 85+ dBA at the operator's ear)
• The visual alarm (typically a flashing red light) is visible from the operator's position under all ambient light conditions
• Warning activates at the manufacturer's specified threshold (commonly 90% of rated capacity)
• Lockout activates at the specified overload threshold (commonly 100–110% of rated capacity, depending on the manufacturer and applicable standard)
• When lockout engages, only the functions that would reduce the load moment remain operational (boom up, hoist down)

Annual Verification

Beyond daily operational checks, LMI and RCI systems require comprehensive annual verification as part of the annual crane inspection. This verification should include:

• Full system calibration check using certified test weights
• Verification of all sensor inputs against independent measurement devices
• Confirmation that the programmed load chart data matches the current crane configuration and manufacturer's latest published capacity data
• Functional test of all alarm and lockout functions at multiple boom lengths and angles
• Inspection of all wiring, connectors, and mounting hardware
• Software update verification to ensure the system runs the current approved firmware
• Documentation of all findings with comparison to previous annual verification results to identify trends

Pendant Control Inspection

Pendant controls are the hand-held control stations used to operate overhead cranes, gantry cranes, and some jib cranes from floor level. Because the operator holds the pendant while standing in the crane's work zone, any malfunction in the pendant control can place the operator directly in harm's way. Pendant controls are addressed in ASME B30.2 for overhead cranes and ASME B30.11 for monorails.

Button and Switch Function Testing

Every control button on the pendant must produce the correct crane motion and only that motion. Testing should verify:

• Each directional button produces the correct motion (up, down, east, west, north, south) as indicated by the label
• Releasing a button immediately stops the associated motion (spring return to center/off is required)
• Multi-speed controls produce the correct speed at each detent position
• No button produces motion in a direction other than what is labeled (cross-wired controls are extremely dangerous)
• The buttons return to their neutral position without sticking, binding, or requiring excessive force
• Simultaneous pressing of opposing directional buttons does not create an unpredictable response

Cable Condition

The pendant control cable connects the pendant station to the crane's control circuit. This cable is subject to constant flexing, pulling, and environmental exposure. Inspect the cable for:

• Outer jacket damage: cuts, abrasion, crushing, chemical exposure, or UV degradation
• Strain relief integrity at both the pendant housing and the junction box connection point
• Proper cable support: the cable should hang freely without kinks, and should be supported by a cable reel, festoon, or retractor where provided
• No evidence of internal conductor damage (intermittent operation when the cable is flexed at different points is a strong indicator)
• Proper cable length: too short creates strain, too long creates a trip hazard and allows the cable to contact the load or floor

Emergency Stop

Every pendant control must include an emergency stop (E-stop) button that, when activated, immediately disconnects power to all crane motions. The E-stop is typically a red mushroom-head push button with a yellow background, conforming to IEC 60947-5-5 or NFPA 79 requirements. Test the E-stop by:

• Pressing the E-stop during crane motion and verifying that all functions cease immediately
• Confirming the E-stop latches in the pressed position and does not self-reset
• Verifying that no crane function operates while the E-stop is latched
• Resetting the E-stop (twist or pull to release) and confirming that the crane does not restart automatically — a deliberate restart action must be required
• Inspecting the E-stop mechanism for physical damage, contamination, or modified operation

Labeling and Identification

ASME B30.2 requires that all pendant control buttons be clearly and durably marked to indicate their function and direction of motion. Markings must be legible and unambiguous. During inspection, verify:

• All buttons are labeled with the function (hoist, trolley, bridge) and direction (up, down, east, west)
• Labels are legible and not worn, faded, or covered by grime
• Directional labels correspond to the actual direction of motion from the operator's normal operating position
• The pendant housing displays the crane identification number
• Warning labels regarding electrical hazard and rated load are present and legible

Grounding and Bonding Requirements

Proper grounding and bonding protect crane operators, riggers, and maintenance personnel from electrical shock. Grounding provides a low-impedance path for fault current to return to the source, enabling protective devices (fuses, circuit breakers, ground-fault relays) to operate and clear the fault. Bonding ensures that all conductive components of the crane are at the same electrical potential, eliminating shock hazards from voltage differences between crane components.

Equipment Grounding

OSHA 1926.1415(a) requires that the crane's electrical system conform to the crane manufacturer's specifications and applicable safety standards. For overhead cranes, the primary equipment grounding path is through the crane structure itself, connected to the building grounding system through the runway rails and their connections to the building steel. Inspect the grounding system by checking:

• The runway rail grounding connections are intact, secure, and show low resistance (typically less than 1 ohm from the crane structure to the building ground bus)
• Rail splice joints have bonding jumpers installed, as rail splice plates alone do not provide a reliable grounding path
• The main grounding conductor from the crane disconnect to the equipment grounding bus is properly sized per the National Electrical Code (NEC) Article 610
• All motors, control enclosures, and metal raceways on the crane are bonded to the crane structure through equipment grounding conductors or through direct metal-to-metal mounting on the crane structure
• Grounding connections are clean, tight, and free from paint, rust, or corrosion that could increase ground path impedance

Ground Fault Protection

Ground fault protection detects current leakage from an energized conductor to ground and interrupts the circuit before the fault current reaches dangerous levels. On cranes, ground fault protection is particularly important because the crane structure itself is a grounded conductor — any insulation failure between a power conductor and the crane frame creates an immediate ground fault.

Modern crane installations should include ground fault relays on the power supply to the crane, with trip settings appropriate for the crane's normal operating current. Inspect ground fault protection by:

• Verifying that ground fault relay or GFCI devices are installed on the crane power supply circuit
• Testing the ground fault device using the manufacturer's test button or by injecting a known test current
• Confirming the trip time and current threshold are within specification
• Checking that the device has not been bypassed, jumpered, or set to an inappropriately high trip level

Lightning Protection

Tower cranes and tall outdoor gantry cranes are particularly vulnerable to lightning strikes. These cranes must have a dedicated lightning protection system that provides a low-impedance path from the highest point of the crane to the ground. As covered in our crane power line safety guide, electrical hazards from external sources require specific protective measures. Lightning protection inspection includes:

• Verify the presence and continuity of the lightning down conductor from the boom tip or tower top to the grounding electrode
• Inspect the grounding electrode (ground rod, ground ring, or connection to building steel) for condition and proper installation
• Measure the ground resistance (should be 25 ohms or less per NEC 250.56 for a single electrode)
• Verify that surge protection devices on sensitive electronic equipment (LMI, radio controls, PLCs) are present and functional

Wiring and Cable Inspection

The wiring infrastructure connects all components of the crane's electrical system. Cranes operate in harsh environments — vibration, temperature extremes, moisture, dust, oil, and mechanical impact all degrade wiring over time. A thorough wiring inspection prevents nuisance failures, short circuits, and electrical fires.

Conductor Insulation

Inspect all accessible wiring for insulation integrity. Look for:

• Cracked, brittle, or discolored insulation indicating heat damage or aging
• Chafed or abraded insulation where cables contact sharp edges, moving parts, or other cables
• Flattened or pinched cables from improper routing or mechanical damage
• Exposed conductor strands at any point along the cable run
• Evidence of overheating: melted insulation, discoloration, or a burnt smell near connections and splices
• Proper cable types for the application — crane duty cables must be rated for the flexing, temperature range, and environmental conditions of the specific installation

Festoon Systems

Festoon cable systems are the suspended cable assemblies that deliver power and control signals along the bridge or trolley travel on overhead cranes. These systems are subject to constant motion and wear. Inspect festoon systems for:

• Trolley carriers moving freely on the C-track or I-beam support without binding or excessive wear
• Cable sag between carriers is uniform and does not allow the cable to contact the crane structure or loads
• Cable strain relief fittings are secure at each carrier
• No missing carriers, broken clamps, or damaged track sections
• End stops on the festoon track are present and secure to prevent carriers from running off the track
• Flat cable festoon systems show no edge damage, twisting, or delamination

Slip Rings and Collector Rings

Slip rings transfer electrical power and signals across rotating joints on cranes — typically at the turntable of a tower crane or the swing mechanism of a mobile crane. Collector rings (also called current collector assemblies) transfer power from stationary conductor bars to the moving crane structure. Both require inspection for:

• Ring surface condition: scoring, pitting, flat spots, or buildup of carbon dust from brush wear
• Brush condition: worn brushes must be replaced before they reach the minimum length marked by the manufacturer
• Brush holder tension: springs must maintain proper pressure to ensure consistent contact
• Insulation between rings: carbon dust or moisture bridging the insulation gaps between rings can create short circuits
• Connection integrity: bolted connections on ring terminals and brush pigtails must be tight and free from corrosion

Junction Boxes and Enclosures

Junction boxes on cranes are the connection points where cables are terminated, spliced, or branched. These enclosures protect the connections from environmental damage and prevent accidental contact with energized conductors. Inspect all junction boxes for:

• Covers are present, properly secured, and sealed against moisture intrusion
• Cable entries use proper strain relief fittings (cord grips, cable glands) — no cables entering through open knockouts without fittings
• Internal connections are tight and show no signs of overheating (discolored terminals, melted wire nuts)
• No unauthorized splices, temporary wiring, or modifications
• NEMA rating of the enclosure is appropriate for the location (NEMA 3R minimum for outdoor, NEMA 4 for washdown environments)

OSHA Electrical Safety Requirements for Cranes

OSHA's crane and derrick standards in 29 CFR 1926 Subpart CC contain specific provisions for electrical systems and safety devices. The two most directly applicable sections are 1926.1415 (Safety Devices) and 1926.1416 (Operational Aids). Understanding the distinction between these sections is essential for compliance.

29 CFR 1926.1415 — Safety Devices: This section covers devices that are required to prevent hazardous conditions and that must be functional for the crane to operate. Safety devices include hoist drum rotation indicators on equipment where the operator cannot directly observe the drum, boom stops (for lattice boom cranes), jib backstops, and equipment-specific safety devices specified by the manufacturer. If a safety device is not functioning, the crane must not be used until the device is repaired.

29 CFR 1926.1416 — Operational Aids: This section covers devices that assist the operator but are not classified as safety devices under 1926.1415. Operational aids include LMI/RCI systems, anti-two-block warning devices (note: the A2B lockout function may be classified as a safety device), boom angle indicators, hoist drum rotation indicators, and outrigger position sensors. If an operational aid is not functioning, the employer must follow a detailed set of procedures in lieu of the device, as specified in 1926.1416(d).

For crane operators and inspectors, the practical implication is that a non-functioning safety device (1926.1415) is an automatic crane shutdown, while a non-functioning operational aid (1926.1416) triggers alternative compliance procedures that must be implemented and documented. As part of your overhead crane inspection frequency planning, ensure that electrical system checks are included in every inspection tier.

Electrical Inspection Checklist

The following table consolidates the key inspection items for crane electrical systems. Use this as a field reference during inspections and integrate these items into your daily crane inspection checklist.

Documentation Requirements

Thorough documentation of electrical system inspections is not merely a best practice — it is a regulatory requirement. OSHA 1926.1412(f) requires that the results of each inspection be documented and retained. For electrical system components, the documentation should include:

• Daily/shift records: Results of all limit switch, A2B, and LMI/RCI functional tests, including pass/fail status, the name of the person who performed the test, and the date and time
• Monthly inspection records: Detailed findings from wiring, grounding, festoon, and junction box inspections, including specific deficiencies noted and corrective actions taken
• Annual inspection records: Comprehensive electrical system evaluation performed by a qualified inspector, including LMI calibration verification, ground resistance measurements, insulation resistance test results, and overall system condition assessment
• Repair records: Documentation of every electrical repair, including the nature of the deficiency, the repair performed, parts replaced, and the name and qualifications of the technician
• Calibration certificates: Current calibration records for the LMI/RCI system, load cells, and any other instruments that require periodic calibration

Maintain these records in a centralized system — digital documentation platforms like CraneCheck allow you to attach inspection findings directly to the specific crane asset, creating a complete electrical maintenance history that satisfies OSHA record-retention requirements. See our guide on crane load chart documentation for additional documentation best practices.

Key Takeaways

• Crane electrical system inspection encompasses limit switches, anti-two-block devices, LMI/RCI systems, pendant controls, grounding, and all interconnecting wiring — every component must be addressed at the correct inspection interval.
• Limit switches and A2B devices must be functionally tested at the start of each shift per OSHA 1926.1416(d)(3). A failed test means the crane is out of service until the device is repaired.
• LMI/RCI calibration is the most critical maintenance activity for load management safety devices. Out-of- calibration systems provide false assurance and are more dangerous than no system at all.
• Pendant control inspection must cover button function, cable condition, emergency stop, and labeling. Cross-wired controls are among the most dangerous electrical faults on overhead cranes.
• Grounding and bonding form the foundation of electrical shock protection. Inspect rail bonds, equipment grounding conductors, and ground fault protection devices at regular intervals.
• OSHA distinguishes between safety devices (1926.1415) and operational aids (1926.1416). A non-functioning safety device requires an immediate shutdown; a non-functioning operational aid triggers alternative compliance procedures.
• Document every electrical inspection, test, calibration, and repair. OSHA requires retention of inspection records, and thorough documentation protects your company during investigations and audits.