Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
---
title: Electric Heat Tracing
category: Electrical
toc_depth: 3
description: >
− When to use: Electrical resistance trace heating applied to piping, vessels, and
− tanks for freeze protection, process temperature maintenance, and roof and gutter
− de-icing, in both ordinary and classified (hazardous) locations, using
− self-regulating, constant-wattage (zone), series-resistance, or mineral-insulated
− cable with associated controls, ground-fault equipment protection, and monitoring.
− Not intended for: Steam or hot-fluid jacketed tracing, impedance or skin-effect
− heating of long transmission pipelines, snow-melt slab heating embedded in
− concrete, or space heating. Pipe insulation systems are specified in
− [[sync/mechanical-insulation]].
+ When to use: Electrical resistance trace heating applied to piping, vessels, and tanks for freeze protection, process temperature maintenance, and roof and gutter de-icing, in both ordinary and classified (hazardous) locations, using self-regulating, constant-wattage (zone), series-resistance, or mineral-insulated cable with associated controls, ground-fault equipment protection, and monitoring.
+ Not intended for: Steam or hot-fluid jacketed tracing, impedance or skin-effect heating of long transmission pipelines, snow-melt slab heating embedded in concrete, or space heating. Pipe insulation systems are specified in [[sync/mechanical-insulation]].
---
…4 unchanged lines
## Electric heat tracing supplies heat to a pipe or vessel to replace heat lost through its insulation, holding the contents at or above a target temperature when the surrounding ambient would otherwise let them cool or freeze. {note}
−## The three governing applications -- freeze protection, process temperature maintenance, and roof and gutter de-icing -- each impose different output, control, and temperature-class requirements, and the selected application drives nearly every other decision in this standard. {note}
+## The three governing applications — freeze protection, process temperature maintenance, and roof and gutter de-icing — each impose different output, control, and temperature-class requirements, and the selected application drives nearly every other decision in this standard. {note}
−## Trace heating output is meaningless without the matching insulation system; the cable wattage, the insulation material, and the insulation thickness are a single coupled design and shall be specified and verified together. {note}
+## Trace heating output is meaningless without the matching insulation system; cable wattage, insulation material, and insulation thickness are a single coupled design. {note}
+### The cable wattage, the insulation material, and the insulation thickness shall be specified and verified together as one design.
+
### The Contractor shall furnish and install a complete trace heating system including heating cable, power connection kits, splice and tee kits, end seals, controls, ground-fault equipment protection, and identification labeling.
…4 unchanged lines
# Referenced Standards {toc}
−## The publications listed below are referenced in this standard; the edition in force is the one adopted by the authority having jurisdiction unless a specific edition is stated. {note}
+## Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+## Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
| Standard | Title |
|----------|-------|
| IEEE 515 | Standard for the Testing, Design, Installation, and Maintenance of Electrical Resistance Trace Heating for Industrial Applications |
| IEEE 515.1 | Standard for the Testing, Design, Installation, and Maintenance of Electrical Resistance Trace Heating for Commercial Applications |
−| NFPA 70 (Article 427) | National Electrical Code — Fixed Electric Heating Equipment for Pipelines and Vessels |
−| NFPA 70 (Articles 500–516) | National Electrical Code — Hazardous (Classified) Locations |
−| NFPA 70E | Standard for Electrical Safety in the Workplace |
+| NFPA 70 | National Electrical Code (Article 427 — Fixed Electric Heating Equipment for Pipelines and Vessels; Articles 500–516 — Hazardous (Classified) Locations) |
| UL 515 | Standard for Electrical Resistance Trace Heating for Commercial Applications |
| UL 515A | Outline of Investigation for Electrical Resistance Trace Heating and Associated Controls for Use in Sprinkler and Standpipe Systems |
−| IEC/IEEE 60079-30-1 | Explosive Atmospheres — Electrical Resistance Trace Heating — Part 1: General and Testing Requirements |
−| IEC 60079-30-2 | Explosive Atmospheres — Electrical Resistance Trace Heating — Part 2: Application Guide |
+| ANSI/UL 60079-30-1 | Explosive Atmospheres — Electrical Resistance Trace Heating — Part 30-1: General and Testing Requirements |
+| ANSI/UL 60079-30-2 | Explosive Atmospheres — Electrical Resistance Trace Heating — Part 30-2: Application Guide for Design, Installation and Maintenance |
| ASHRAE 90.1 | Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings |
…28 unchanged lines
type: checkbox
options:
− - Product data -- cable, kits, controls, GFEP
+ - Product data — cable, kits, controls, GFEP
- Heat-loss and cable output calculations
- Circuit schedule
- Maximum circuit length and inrush data
- Classified-location listing and T-class documentation
− - Shop drawings -- routing and component locations
+ - Shop drawings — routing and component locations
- Control and GFEP wiring diagrams
default:
− - Product data -- cable, kits, controls, GFEP
+ - Product data — cable, kits, controls, GFEP
- Heat-loss and cable output calculations
- Circuit schedule
− - Shop drawings -- routing and component locations
+ - Maximum circuit length and inrush data
+ - Shop drawings — routing and component locations
+ - Control and GFEP wiring diagrams
```
…42 unchanged lines
- Insulation-resistance test records
- Continuity and GFEP functional test records
+ - ASHRAE 90.1 energy-compliance documentation
- Operation and maintenance manuals and warranty
```
…15 unchanged lines
# Environmental and Service Conditions {toc}
−## The design ambient is the lowest temperature the system must perform at, not the average winter temperature; sizing to an average leaves circuits short on the coldest nights, which is when they are needed. {note}
+## The design ambient is the lowest temperature the system must perform at, not the average winter temperature; sizing to an average leaves circuits short on the coldest nights, which is when they are needed.
−### The minimum design ambient temperature shall be the basis for heat-loss calculation and cable output selection.
+### The minimum design ambient temperature shall be as indicated in the datasheet and shall be the basis for heat-loss calculation and cable output selection.
```datasheet
label: Minimum Design Ambient Temperature
type: range
unit: °F
−min: -40
−max: 40
−step: 5
−default: 0
+options:
+ min: -60
+ max: 50
+ step: 5
```
−### The maintain temperature is the lowest temperature the system holds at the pipe under the minimum design ambient. {note}
+### The design ambient is read from the project's climatic design criteria for the site, so no temperature is correct for every project and the field carries no default. {note}
−### Freeze protection shall maintain the pipe contents at or above the freeze-protection setpoint under the minimum design ambient.
+### The application type shall be as indicated in the datasheet.
```datasheet
…4 unchanged lines
- Process temperature maintenance
- Roof and gutter de-icing
−default: Freeze protection
```
+### The application governs the cable output, the control strategy, and the temperature class, and this standard covers all three applications in comparable numbers, so the field carries no default. {note}
+
+### The maintain temperature is the lowest temperature the system holds at the pipe under the minimum design ambient. {note}
+
+### Freeze protection shall maintain the pipe contents at or above the freeze-protection setpoint under the minimum design ambient.
+
+### The maintain temperature shall be as indicated in the datasheet.
+
```datasheet
label: Maintain Temperature
type: range
unit: °F
−min: 40
−max: 250
−step: 5
−default: 40
+options:
+ min: 35
+ max: 500
+ step: 5
```
−### Wind increases convective heat loss from insulated pipe; exposed outdoor runs shall include a wind-speed allowance in the heat-loss calculation.
+### Freeze protection is typically maintained near 40°F while process maintenance runs anywhere from just above ambient to several hundred degrees, so no maintain temperature is correct for every project and the field carries no default. {note}
+### Wind increases convective heat loss from insulated pipe; exposed outdoor runs shall include the wind-speed allowance indicated in the datasheet in the heat-loss calculation.
+
```datasheet
label: Heat-Loss Design Wind Speed
type: range
unit: mph
−min: 0
−max: 40
−step: 5
+options:
+ min: 0
+ max: 40
+ step: 5
default: 20
```
+### A 20 mph design wind is the conventional heat-loss basis for exposed outdoor pipe and is correct without knowing the project; it is lowered only for sheltered or indoor runs and raised for exposed coastal and rooftop installations. {note}
+
### The maximum exposure temperature is the highest temperature the de-energized cable will see, set by process upsets, steam-out, or solar gain, and it shall not exceed the cable's rated exposure temperature.
+### The maximum pipe exposure temperature shall be as indicated in the datasheet.
+
```datasheet
label: Maximum Pipe Exposure Temperature
type: range
unit: °F
−min: 100
−max: 1200
−step: 25
−default: 200
+options:
+ min: 100
+ max: 1200
+ step: 25
```
+### The exposure temperature comes from the process design — steam-out, regeneration, or upset conditions — so the field carries no default. {note}
+
# Area Classification {toc}
## Specifying a general-purpose cable in a classified area is a code violation and an ignition hazard; the area classification governs the cable and every accessory in the circuit, not just the controller. {note}
−### The area classification of each circuit shall be established from the project hazardous-area drawings.
+### The area classification of each circuit shall be as indicated in the datasheet.
−### Cable and accessories in an ordinary (unclassified) location shall be listed for general-purpose use.
−
−### Cable and accessories in a classified location shall be listed to the requirements for explosive atmospheres and marked with the applicable temperature class.
−
```datasheet
label: Area Classification
type: radio
+drawing_ref: "hazardous area classification drawings"
options:
- Ordinary (unclassified)
- Class I Division 2 / Zone 2
- Class I Division 1 / Zone 1
- Class II Division 2 (dust)
−default: Ordinary (unclassified)
+ - Class II Division 1 (dust)
+default: deferred
```
+### Cable and accessories in an ordinary (unclassified) location shall be listed for general-purpose use.
+
+### Cable and accessories in a classified location shall be listed to the requirements for explosive atmospheres and marked with the applicable temperature class.
+
+### The temperature class required for each circuit shall be as indicated in the datasheet.
+
```datasheet
label: Temperature Class (Classified Locations)
type: radio
options:
− - T1 (450 °C)
− - T2 (300 °C)
− - T3 (200 °C)
− - T4 (135 °C)
− - T5 (100 °C)
− - T6 (85 °C)
−default: T3 (200 °C)
+ - Not applicable (ordinary location)
+ - T1 (450°C)
+ - T2 (300°C)
+ - T3 (200°C)
+ - T4 (135°C)
+ - T5 (100°C)
+ - T6 (85°C)
```
+### The temperature class is set by the autoignition temperature of the material that makes the location hazardous, which the project's area classification study establishes, so the field carries no default. {note}
+
# Heating Cable {toc}
…2 unchanged lines
### The technologies differ in where they fit: {note}
−- **Self-regulating parallel cable** is the default for freeze protection and moderate process maintenance because its output falls as the pipe warms, it cannot overheat on overlap, and it tolerates being cut to length in the field.
−- **Constant-wattage (zone) cable** suits long uniform runs where a fixed output per unit length is acceptable, but it offers no self-limiting and shall not be overlapped.
+- **Self-regulating parallel cable** is the usual choice for freeze protection and moderate process maintenance because its output falls as the pipe warms, it cannot overheat on overlap, and it tolerates being cut to length in the field.
+- **Constant-wattage (zone) cable** suits long uniform runs where a fixed output per unit length is acceptable, but it offers no self-limiting and cannot be overlapped.
+- **Series-resistance cable** energizes a single heating conductor as one long circuit and suits large industrial runs whose length is fixed at design.
- **Mineral-insulated cable** is used where sheath temperatures exceed the polymer range or where maximum ruggedness is required, and because it is factory-terminated to length it cannot be field-cut.
−### The Contractor shall furnish the heating cable technology selected for each circuit.
+### The Contractor shall furnish the heating cable technology indicated in the datasheet.
```datasheet
…8 unchanged lines
```
−### The rated power output shall be selected from the heat-loss calculation for the pipe size, maintain temperature, minimum ambient, and insulation system, and undersizing the output is a critical error that the calculation exists to prevent.
+### Self-regulating cable is the datasheet default because it is the technology this standard's own narrative identifies as the baseline for freeze protection and moderate process maintenance; the other three are selected for long fixed-length runs, high sheath temperatures, or extreme ruggedness. {note}
+### The rated power output shall be as indicated in the datasheet and shall be selected from the heat-loss calculation for the pipe size, maintain temperature, minimum ambient, and insulation system.
+
```datasheet
−label: Rated Power Output at 50 °F
+label: Rated Power Output at 50°F
type: range
unit: W/ft
−min: 3
−max: 40
−step: 1
−default: 8
+options:
+ min: 3
+ max: 60
+ step: 1
```
+### The output is the result of the heat-loss calculation, and undersizing it is the critical error that calculation exists to prevent, so the field carries no default. {note}
+
### The supply voltage governs the maximum circuit length and the conductor losses; higher voltage allows longer circuits but raises the cold-start inrush that the breaker must tolerate. {note}
−### The Contractor shall energize each circuit at the supply voltage shown for that circuit.
+### Each circuit shall be energized at the supply voltage indicated in the datasheet.
```datasheet
label: Supply Voltage
type: radio
+drawing_ref: "heat trace circuit schedule"
options:
- 120 V 1Φ
…2 unchanged lines
- 277 V 1Φ
- 480 V 1Φ
−default: 240 V 1Φ
+default: deferred
```
−### The cable jacket shall be selected for the chemical and thermal exposure of its location. {note}
+### The cable jacket shall be selected for the chemical and thermal exposure of its location.
−### General-purpose runs shall use a polyolefin outer jacket.
+### The cable outer jacket material shall be as indicated in the datasheet.
−### Runs exposed to chemicals, high temperature, or organic corrosives shall use a fluoropolymer outer jacket.
−
−### Runs requiring grounding continuity or mechanical protection shall include a metallic braid, and runs subject to impact shall include a metal armor overjacket.
−
```datasheet
label: Outer Jacket Material
…6 unchanged lines
```
+### General-purpose runs shall use a polyolefin outer jacket unless a different jacket is indicated in the datasheet.
+
+### Runs exposed to chemicals, high temperature, or organic corrosives shall use a fluoropolymer outer jacket.
+
+### The metallic braid and overjacket construction shall be as indicated in the datasheet.
+
```datasheet
label: Metallic Braid / Overjacket
…7 unchanged lines
```
−### A continuous metallic braid is required by NEC Article 427 to provide an equipment grounding path along the cable and to serve as the reference for ground-fault sensing; it shall not be omitted. {note}
+### Runs requiring grounding continuity or mechanical protection shall include a metallic braid, and runs subject to impact shall include a metal armor overjacket.
+### NEC Article 427 requires a continuous metallic braid to provide an equipment grounding path along the cable and to serve as the reference for ground-fault sensing. {note}
+
### Every heating cable shall have a continuous metallic braid bonded to the equipment grounding system in accordance with [[sync/grounding-and-bonding]].
…2 unchanged lines
## Self-regulating cable draws a large cold-start inrush current at low ambient because the cold core is at its lowest resistance; if the breaker trips on that inrush, the circuit never starts, so the breaker must be coordinated with the inrush, not just the steady-state load. {note}
−### The maximum circuit length shall not exceed the manufacturer's published maximum for the selected cable, voltage, and minimum start-up temperature.
+### The maximum circuit length shall not exceed the manufacturer's published maximum for the selected cable, the supply voltage, and the minimum start-up temperature indicated in the datasheet.
```datasheet
label: Minimum Start-Up Temperature for Length Rating
type: range
unit: °F
−min: -40
−max: 50
−step: 5
−default: 0
+options:
+ min: -60
+ max: 50
+ step: 5
```
−### The branch-circuit breaker shall be sized for the cold-start inrush current and shall use a trip characteristic that tolerates that inrush without nuisance tripping.
+### The start-up temperature is the coldest condition at which the circuit must be able to be energized from cold, which follows from the site's design ambient and the operating regime, so the field carries no default. {note}
+### The branch-circuit breaker shall have the trip characteristic indicated in the datasheet, selected to tolerate the cold-start inrush without nuisance tripping.
+
```datasheet
label: Branch Circuit Breaker Trip Characteristic
type: radio
options:
- Standard thermal-magnetic (inverse time)
− - High-magnetic / time-delay (Type D equivalent)
−default: High-magnetic / time-delay (Type D equivalent)
+ - High-magnetic / time-delay (inrush-rated)
+default: High-magnetic / time-delay (inrush-rated)
```
+### An inrush-rated breaker is the default because self-regulating cable is the default technology and its cold-start inrush trips a standard thermal-magnetic device on long circuits; a standard breaker remains a valid selection on short circuits and on constant-wattage cable, whose inrush is modest. {note}
+
+### The branch-circuit breaker rating shall be as indicated in the datasheet.
+
```datasheet
label: Branch Circuit Breaker Rating
type: range
unit: A
−min: 15
−max: 50
−step: 5
−default: 20
+drawing_ref: "heat trace circuit schedule"
+options:
+ min: 15
+ max: 60
+ step: 5
+default: deferred
```
…8 unchanged lines
### Each heating circuit shall be protected by a listed ground-fault equipment-protection device.
−### The ground-fault equipment-protection trip level shall be set for equipment protection, not personnel protection.
+### The ground-fault equipment-protection trip level shall be as indicated in the datasheet and shall be set for equipment protection rather than personnel protection.
```datasheet
label: GFEP Trip Level
−type: radio
+type: range
+unit: mA
options:
− - 30 mA
− - 20 mA
− - 50 mA
−default: 30 mA
+ min: 20
+ max: 50
+ setpoints: [20, 30, 50]
+default: 30
```
+### 30 mA is the trip level the trace heating industry and IEEE 515 settled on for equipment protection and is correct without knowing the project; 20 mA suits short circuits where a tighter trip is wanted, and 50 mA is used on long circuits with high distributed leakage. {note}
+
### A circuit whose distributed leakage approaches the trip level shall be subdivided into shorter circuits rather than raising the trip level above the equipment-protection range.
…8 unchanged lines
- **Electronic control with an RTD probe** gives the most accurate temperature hold, the greatest energy savings, and an interface to the building automation or SCADA system.
−### The Contractor shall furnish the control strategy selected for each circuit or group of circuits.
+### The Contractor shall furnish the control strategy indicated in the datasheet for each circuit or group of circuits.
```datasheet
…4 unchanged lines
- Line/pipe-sensing thermostat
- Electronic controller with RTD sensing
−default: Ambient-sensing thermostat
```
+### The control strategy follows from the application and the criticality of the traced service, both of which are project decisions, so the field carries no default. {note}
+
### A single thermostat cannot correctly control branches with different heat-loss characteristics; each major application or branch shall have independent control and independent ground-fault equipment protection.
−### Control enclosures installed outdoors or in wet locations shall be rated NEMA 4X.
+### The control enclosure rating shall be as indicated in the datasheet.
```datasheet
label: Control Enclosure Rating
type: radio
options:
− - NEMA 4X
+ - NEMA 1 (indoor, dry)
+ - NEMA 12 (indoor, dust and dripping liquid)
- NEMA 4
+ - NEMA 4X
- NEMA 7 (classified location)
default: NEMA 4X
```
−### The control setpoint shall be field-set to the maintain temperature and recorded on the as-built circuit schedule.
+### Control enclosures installed outdoors or in wet locations shall be rated NEMA 4X.
+### NEMA 4X is the datasheet default because trace heating controls are predominantly mounted outdoors or in wet process areas; the indoor ratings are selected only where the panel sits in a conditioned electrical room. {note}
+
+### The control setpoint shall be as indicated in the datasheet and shall be recorded on the as-built circuit schedule.
+
```datasheet
label: Control Setpoint
type: range
unit: °F
−min: 38
−max: 250
−step: 2
−default: 40
+options:
+ min: 20
+ max: 500
+ step: 2
```
+### For line- and pipe-sensing control the setpoint is the maintain temperature; for ambient-sensing control it is an air-temperature cut-in that is normally set above the maintain temperature. The two cases give different answers, so the field carries no default. {note}
+
### The responsibility for furnishing and setting thermostats and controllers shall be assigned in the circuit schedule so that control does not fall between the cable and the controls scopes.
…2 unchanged lines
## Basic systems annunciate only on a ground-fault trip, which means a cable that has stopped heating for any other reason goes unnoticed until the pipe freezes; current monitoring detects that loss of heat before the failure. {note}
−### The level of monitoring shall be selected for the criticality of the traced service.
+### The level of monitoring shall be as indicated in the datasheet and shall be selected for the criticality of the traced service.
```datasheet
label: Monitoring Level
type: radio
options:
− - GFEP trip indication only
+ - GFEP trip indication
- Per-circuit current and ground-fault monitoring
- Per-circuit monitoring with BAS/SCADA interface
−default: GFEP trip indication only
```
+### Monitoring is a criticality judgment — a freeze-protected exterior hose bibb and a freeze-protected fire sprinkler main warrant very different answers — so the field carries no default. {note}
+
### A heat trace monitoring panel, where provided, shall measure per-circuit current and ground-fault leakage and shall annunciate loss of continuity.
…6 unchanged lines
### All power connection, splice, tee, and end-seal kits shall be from the same listed system as the heating cable.
−### Every heating cable terminus shall be sealed with a factory-listed end seal; an unsealed end admits moisture and is the leading cause of insulation-resistance failure and ground-fault nuisance tripping. {note}
+### An unsealed cable end admits moisture and is the leading cause of insulation-resistance failure and ground-fault nuisance tripping. {note}
### A listed end seal shall be installed at the end of every heating cable run.
…3 unchanged lines
### A listed splice or tee kit shall be installed wherever heating cable sections are joined.
+### The end-of-circuit component shall be as indicated in the datasheet.
+
```datasheet
label: End-of-Circuit Component
…5 unchanged lines
```
+### A plain end seal is the baseline; a lighted end seal adds a visible indication that the circuit is energized and is worth its cost where circuits are inspected by walking the line. {note}
+
+### The junction box enclosure rating shall be as indicated in the datasheet.
+
```datasheet
label: Junction Box Enclosure Rating
type: radio
options:
− - NEMA 4X
+ - NEMA 12 (indoor, dust and dripping liquid)
- NEMA 4
+ - NEMA 4X
- NEMA 7 (classified location)
default: NEMA 4X
…2 unchanged lines
# Pipe and Material Compatibility {toc}
−## A high-temperature cable energized at low ambient can drive its surface above the service temperature of a plastic pipe, softening or failing the pipe; the cable surface temperature shall be verified against the pipe rating, not assumed safe. {note}
+## A high-temperature cable energized at low ambient can drive its surface above the service temperature of a plastic pipe, softening or failing the pipe; the cable surface temperature shall be verified against the pipe rating, not assumed safe.
### The maximum cable surface temperature shall not exceed the service temperature rating of the pipe material it is applied to.
…3 unchanged lines
### Freeze protection of domestic water piping shall be coordinated with [[sync/domestic-water-piping]], and freeze protection of hydronic piping with [[sync/hydronic-piping]].
+### The traced pipe material shall be as indicated in the datasheet.
+
```datasheet
label: Pipe Material
type: radio
+drawing_ref: "piping drawings"
options:
- Carbon steel
- Stainless steel
+ - Ductile iron
- Copper
- CPVC
+ - PVC
- PEX
−default: Carbon steel
+ - Fiberglass reinforced plastic (FRP)
+default: deferred
```
…8 unchanged lines
### De-icing cable shall be controlled by an automatic ambient- or moisture-sensing control so it operates only during icing conditions, as required for energy compliance.
−### Cable routing in valleys, gutters, downspouts, and at the eave edge shall follow [[drawing: roof de-icing layout]].
+### Cable routing in valleys, gutters, downspouts, and at the eave edge shall be [[drawing: as indicated on the roof de-icing layout]].
+### The de-icing cable output shall be as indicated in the datasheet.
+
```datasheet
−label: De-Icing Cable Output at 40 °F
+label: De-Icing Cable Output at 40°F
type: range
unit: W/ft
−min: 5
−max: 20
−step: 1
−default: 12
+options:
+ min: 3
+ max: 20
+ step: 1
```
+### De-icing output is set by the roof geometry, the snow load, and the wattage ceiling the adopted energy code imposes on this application, so the field carries no default. {note}
+
# Energy Compliance {toc}
…10 unchanged lines
## NEC Article 427.13 requires warning labels because the heating cable is hidden under insulation and is invisible to anyone working on the pipe; without the label requirement in the specification, field crews do not install them and the system fails inspection. {note}
−### A caution label identifying the presence of electric heat tracing shall be applied to the pipe insulation jacket at intervals and at every point of access.
+### A caution label identifying the presence of electric heat tracing shall be applied to the pipe insulation jacket at intervals not exceeding the interval indicated in the datasheet, and at every point of access.
−### Each caution label shall identify the circuit voltage and the location of the controlling ground-fault protection panel.
−
−### The presence of heat tracing shall be marked on the outer insulation jacket so it is visible before the insulation is opened.
−
```datasheet
label: Caution Label Interval
type: range
unit: ft
−min: 5
−max: 20
−step: 5
+options:
+ min: 5
+ max: 20
+ step: 5
default: 10
```
+### A 10 ft maximum interval is the value NEC Article 427.13 establishes and is correct without knowing the project; a shorter interval is specified only where access points are unusually dense. {note}
+
+### Each caution label shall identify the circuit voltage and the location of the controlling ground-fault protection panel.
+
+### The presence of heat tracing shall be marked on the outer insulation jacket so it is visible before the insulation is opened.
+
# Testing {toc}
…2 unchanged lines
### The Contractor shall perform an insulation-resistance test on each circuit before energization and again after installation of the pipe insulation.
−### Polymer-insulated cable shall be insulation-resistance tested at 2500 Vdc between the heating conductor and the metallic braid.
+### Polymer-insulated cable shall be insulation-resistance tested between the heating conductor and the metallic braid at the dc test voltage indicated in the datasheet.
```datasheet
−label: Insulation-Resistance Test Voltage -- Polymer Cable
+label: Insulation-Resistance Test Voltage — Polymer Cable
type: radio
options:
…3 unchanged lines
```
−### Mineral-insulated cable shall be insulation-resistance tested at the test voltage specified by the cable manufacturer.
+### 2500 Vdc is the test voltage IEEE 515 establishes for polymer-insulated trace heating cable and is correct without knowing the project; 1000 Vdc is used where an existing installation is being retested and the manufacturer limits the applied voltage. {note}
+### Mineral-insulated cable shall be insulation-resistance tested at the dc test voltage indicated in the datasheet.
+
```datasheet
−label: Insulation-Resistance Test Voltage -- MI Cable
+label: Insulation-Resistance Test Voltage — MI Cable
type: radio
options:
- 1000 Vdc
- 500 Vdc
−default: 1000 Vdc
+default: manufacturer
```
−### The measured insulation resistance of each circuit shall meet or exceed the minimum value specified by the manufacturer.
+### The MI cable manufacturer publishes the test voltage for its sheath and termination system, and that value is acceptable; where a test voltage is indicated in the datasheet it governs, and the manufacturer shall report the value used in the test record.
+### The measured insulation resistance of each circuit shall meet or exceed the minimum value indicated in the datasheet.
+
```datasheet
label: Minimum Acceptable Insulation Resistance
type: range
unit: MΩ
−min: 20
−max: 1000
−step: 10
−default: 20
+options:
+ min: 20
+ max: 1000
+ step: 10
```
+### The manufacturer's published minimum insulation resistance for the cable and circuit length is acceptable and is the datasheet default; a higher minimum is entered only where the Owner imposes a stricter acceptance criterion. {note}
+
### A circuit that fails the insulation-resistance test shall not be energized until the fault is located and corrected.
…18 unchanged lines
### Additional cable length shall be applied at valves, flanges, pipe supports, and instruments to replace their added heat loss, in accordance with the manufacturer's heat-sink allowances.
+### The cable routing pattern shall be as indicated in the datasheet.
+
```datasheet
label: Cable Routing Pattern
…6 unchanged lines
```
+### A single straight run along the lower quadrant of the pipe is the baseline arrangement; multiple runs and spiral wrap are used where the heat-loss calculation calls for more cable per foot of pipe than one straight run delivers. {note}
+
### Self-regulating cable may be overlapped on itself at heat sinks; constant-wattage and series-resistance cable shall not be overlapped.
−### The point of power connection, the end-of-circuit location, and the splice and tee locations shall be installed per [[drawing: heat trace circuit layout]].
+### The point of power connection for each circuit shall be [[drawing: as indicated on the heat trace circuit layout]].
−### Control and sensor probes shall be located on the pipe at the position shown so they sense the controlling temperature rather than a local hot or cold spot, per [[drawing: control sensor locations]].
+### The end-of-circuit location for each circuit shall be [[drawing: as indicated on the heat trace circuit layout]].
+### Splice and tee locations shall be [[drawing: as indicated on the heat trace circuit layout]].
+
+### Control and sensor probes shall be located on the pipe so they sense the controlling temperature rather than a local hot or cold spot, [[drawing: as indicated on the control sensor location plan]].
+
### No section of pipe insulation shall be installed over a heating circuit that has not passed its pre-insulation insulation-resistance test.
…14 unchanged lines
# Warranty {toc}
−## The Contractor shall warrant the complete trace heating system against defects in materials and workmanship for the warranty period.
+## The Contractor shall warrant the complete trace heating system against defects in materials and workmanship for the warranty period indicated in the datasheet.
```datasheet
label: System Warranty Period
−type: radio
+type: range
+unit: years
options:
− - 1 year
− - 2 years
− - 5 years
−default: 1 year
+ min: 1
+ max: 5
+ setpoints: [1, 2, 5]
+default: 1
```
−### The heating cable manufacturer's warranty for the cable and accessories shall be assigned to the Owner at closeout.
+## The heating cable manufacturer's warranty for the cable and accessories shall be assigned to the Owner at closeout.
# Spare Parts {toc}
## Trace heating accessories are manufacturer-specific and not stocked locally, so a future repair without spares means an extended outage on the traced service; a small spare stock keeps the system maintainable. {note}
−### The Contractor shall furnish spare power connection, splice, and end-seal kits matching the installed system.
+### The Contractor shall furnish spare power connection, splice, and end-seal kits matching the installed system, in the proportion indicated in the datasheet.
```datasheet
−label: Spare Connection and End-Seal Kits
+label: Spare Connection and End-Seal Kits (percent of installed quantity)
type: range
−unit: percent of installed quantity
−min: 0
−max: 25
−step: 5
+unit: '%'
+options:
+ min: 0
+ max: 25
+ step: 5
default: 10
```
−### The Contractor shall furnish spare heating cable of each installed type for future repairs.
+### The Contractor shall furnish spare heating cable of each installed type for future repairs, in the length indicated in the datasheet.
```datasheet
−label: Spare Heating Cable -- Each Type
+label: Spare Heating Cable — Each Type
type: range
unit: ft
−min: 0
−max: 100
−step: 10
+options:
+ min: 0
+ max: 100
+ step: 10
default: 30
```
+
+### The 10% kit allowance and the 30 ft cable allowance are contractual spare-stock floors rather than sized quantities, so both carry concrete defaults. {note}