Labeling of Wire and Cable in Electrical Work
- All control, power wires, and low voltage instrument pairs and triads shall be labeled at each termination point. The numbers and letters shall be typewritten and shall correspond with those shown on the termination schedules and contract drawings. Labels shall be white and printed with a thermal transfer printer. Labels shall be Panduit polyolefin thermal transfer labels, Brady Co. Permasleeve™ marker or equivalent heat shrink, sleeve-type wire markers. Wire sizes 2/0 AWG and above may use Panduit marker plate labels #M300X050Y or equal. The labels to be positioned directly adjacent to the lug or terminal and the description shall be visible without manipulating the wire.
- All multiconductor cables and cable bundles shall be labeled at each end. The numbers and letters shall correspond to the cable numbers shown on the cable schedules and contract drawings. Cable markers shall be Panduit marker plate labels per paragraph above.
- Do not shrink wire markers until requested by the field representative. Heat shrinking of markers on wires terminating in Programmable Electronic System (PES) cabinets and other sensitive electronic equipment shall be performed before termination of wire on terminal strip to prevent possible damage to electronic equipment caused by overheating.
Labeling of Wires, Cables, Electrical Areas and Equipment in Electrical Work
- All signs and labels shall be furnished and installed by the contractor.
- All substation yards and transformer areas must be labeled with permanently attached “High Voltage” warning signs on the fences. The signs shall also indicate the highest level of voltage that exists inside the fenced area. Signs shall be UV- and chemical-resistant rigid polyethylene or painted aluminum. Signs shall be attached to fence with stainless steel self-locking cable ties. Other warning signs shall be installed as required by NEC article ‘Outside Branch Circuits and Feeders’, ‘Substations’.
- Electrical rooms and buildings or any other structures that contain electrical equipment must be labeled with permanently attached warning signs on the outside of all doors to communicate the electrical hazards that exist inside. If equipment operating above 600 volts AC is present in the structure, “High-Voltage” warning signs must also be posted. The signs shall indicate the highest level of voltage that exists inside.
- All switchgear, starter, and motor control center compartments must be labeled with permanently attached warning signs on the doors, including side and rear access panels, to indicate the highest level of voltage that exists inside. If high-voltage equipment is present, “High-Voltage” warning signs must also be posted.
- For outdoor starters and motor control centers provided with weatherproof enclosures surrounding the equipment, in addition to labeling the equipment as identified in the preceding paragraphs, all access doors of the enclosure shall also be labeled with permanently attached warning signs on the doors to indicate the highest level of voltage that exists inside. If high-voltage equipment is present, “High-Voltage” warning signs must also be posted.
- Covers, doors, and access panels of junction boxes, terminal boxes, pull boxes, transformer terminal chambers, motor terminal boxes, panelboards, and all other electrical enclosures and equipment shall be labeled with the highest voltage level contained inside.
- Medium voltage conduit system access locations pull boxes and condulet fitting covers shall be labeled with the voltage level contained inside.
- Signs identified in paragraphs above shall be UV- and chemical-resistant self-adhesive polyester film or equivalent.
- All microwave antennas (dish and other types, including poles and masts) must have signs placed adjacent to them warning personnel of the dangers associated with radiation hazards. This includes systems for telemetering, control, computer, and video communications that use microwave communication systems. The sign shall read:
- “CAUTION – Radiation in this area may exceed hazard limitations and special precautions may be required. De-energize or obtain specific instructions before working near or looking into the center of the antenna.” or equivalent.
- In addition to installing warning labels, the following electrical equipment identification labels must also be provided on electrical equipment. Unless noted otherwise, labels shall be laminated plastic and suitable for the environment in which they are installed.
- All disconnect switches, high and low voltage, shall be labeled to identify the equipment being served either by attachment of a label directly to or adjacent to the disconnect switch.
- Inside of each motor control center cubicle door, list the following: equipment number and name, load size/motor horsepower (HP), service factor, full-load/service factor amps, fuse size, and overload heater number and rating. This information may be typed on adhesive-backed cards.
- Weatherproof enclosures on outdoor switchgear, starters, and motor control centers with main disconnect means. The access doors to the disconnect shall have a sign labeled “Main Disconnect.”
- Each line-up of switchgear, starters, and motor control centers and all control panels, panelboards, terminal boxes, and control stations shall be provided with nameplates. If wording is not identified as part of contract drawings contact an Air Products representative for proper wording.
- Each lighting switch, convenience outlet, manual starter, heater, and other similar items, shall be provided with a nameplate indicating the supply panelboard and circuit protective device number. Labels may be self-adhesive polyester film or equivalent.
- Each piece of equipment or enclosures containing multiple power supplies shall be provided with a nameplate indicating the supply panelboard and circuit protective device number for each power supply.
- All transformers shall be labeled showing the location of the primary disconnect per the NEC. The label shall include panel or MCC number, breaker or bucket number or switchgear cubical.
- Per the NEC article 392, all cable trays with conductors over 600 volts shall be labeled with the wording “DANGER – HIGH VOLTAGE – KEEP AWAY” placed on both side rails where visible for all cable tray segments throughout the plant. The spacing of the warning signs shall not exceed 3 m (10 ft).
- All other cable trays shall be labeled as described in the following paragraphs. Labels shall be placed on both side rails where visible on all cable tray segments throughout the plant. Where cable trays contain a barrier with different cable systems on each side the side rail should reflect the cable type directly behind it. The spacing of the warning signs shall not exceed 15 m (50 ft).
– All cable trays with conductors rated >50 to 600 volts shall be labeled with the wording “LOW VOLTAGE POWER AND CONTROL – _____ VOLTS” Fill in the highest voltage in the tray system, usually from the LV motor control center.
– All cable trays with 24VDC instruments, Thermocouples and RTDs shall be labeled with the wording “INSTRUMENTATION”.
– All cable trays with computer network, telephone, fiber optics shall be labeled with the wording “COMMUNICATIONS”.
– Intrinsic safe wiring systems shall be labeled with the wording “INTRINSIC SAFETY WIRING”. Labels shall be placed on all trays, conduit and other similar items.