#### 7.2.3.19 IfcJunctionBox

| Boite de jonction
| Verbindungsdose

A junction box is an enclosure within which cables are connected.

Cables may be members of an electrical circuit (for electrical power systems) or be information carriers (in a telecommunications system). A junction box is typically intended to conceal a cable junction from sight, eliminate tampering or provide a safe place for electrical connection.

> HISTORY New entity in IFC4

## Electrical System Design

The following concepts are inherited at supertypes:

- IfcDistributionElement: Footprint Geometry

Instance diagram

Identity

The Identity concept applies to this entity.

Exchange |  |  |  |  |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Import |  |  |  |  |  |  | R | R |  |  | R | R | R
Export |  |  |  |  |  |  | R | R |  |  | R | R | R

Object Typing

The Object Typing concept applies to this entity as shown in Table 115.

Type
IfcJunctionBoxType
IfcDistributionElementType
Table 115 — IfcJunctionBox Object Typing

Exchange |  |  |  |  |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Import |  |  |  |  |  |  |  |  |  |  |  |  | R
Export |  |  |  |  |  |  |  |  |  |  |  |  | R

Properties for Occurrences

The Properties for Occurrences concept applies to this entity as shown in Table 116.

PredefinedType | Name
--- | ---
| Pset_JunctionBoxTypeCommon
| Pset_ElectricalDeviceCommon
Table 116 — IfcJunctionBox Properties for Occurrences

Exchange |  |  |  |  |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Import |  |  |  |  |  |  |  | R |  |  |  |  | R
Export |  |  |  |  |  |  |  | R |  |  |  |  | R

Ports

The Ports concept applies to this entity as shown in Table 117.

PredefinedType | Name | Flow | Type | Description
--- | --- | --- | --- | ---
DATA | Line#1 | SINK | DATA | A data line, typically a cable connecting from a network router communications device.
DATA | Line#2 | SINK | DATA | A data line, typically a cable connecting from a network router communications device.
DATA | Gang#1 | SOURCE | DATA | A slot to house a data outlet containing one or more jacks, ordered from left-to-right.
DATA | Gang#2 | SOURCE | DATA | A slot to house a data outlet containing one or more jacks, ordered from left-to-right.
POWER | Line | SINK | ELECTRICAL | The electrical supply line, typically a cable connecting from another junction box or from a protective device within a distribution board.
POWER | Load | SOURCE | ELECTRICAL | The next load in the circuit, typically a cable connecting to another junction box.
POWER | Gang#1 | SOURCE | ELECTRICAL | A slot to house a switch or outlet, ordered from left-to-right.
POWER | Gang#2 | SOURCE | ELECTRICAL | A slot to house a switch or outlet, ordered from left-to-right.
POWER | Gang#3 | SOURCE | ELECTRICAL | A slot to house a switch or outlet, ordered from left-to-right.
POWER | Gang#4 | SOURCE | ELECTRICAL | A slot to house a switch or outlet, ordered from left-to-right.
Table 117 — IfcJunctionBox Ports

Exchange |  |  |  |  |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Import |  |  |  |  |  |  |  | R |  |  |  |  | R
Export |  |  |  |  |  |  |  | R |  |  |  |  | R

Spatial Containment

The Spatial Containment concept applies to this entity.

Exchange |  |  |  |  |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Import |  |  |  |  |  |  |  | R |  |  |  |  | R
Export |  |  |  |  |  |  |  | R |  |  |  |  | R

Placement

The Placement concept applies to this entity.

Exchange |  |  |  |  |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Import |  |  |  |  |  |  |  | R |  |  | R |  | R
Export |  |  |  |  |  |  |  | R |  |  | R |  | R

Body Geometry

The Body Geometry concept applies to this entity as shown in Table 118.

RepresentationType | Geometry | Description
--- | --- | ---
Brep | IfcFacetedBrep | All fixtures (all non distribution flow elements, i.e. everything which is not a duct, a pipe, a cable, or a cable carrier) should be defined by an b-rep geometry. This includes also the complex flow fitting elements (e.g. Y branch or T branch) or distribution flow elements with size changes (e.g. reducer).
SurfaceModel | IfcFaceBasedSurfaceModel | If the geometric model consistency of a b-rep shape representation can not be guaranteed (arcwise connected volume bounded by faces, each being connected, oriented, finite, closed 2-manifold), a surface representation based on open shells should be used.
SweptSolid | IfcExtrudedAreaSolid | All "simple" distribution flow elements (general ducts and pipes) are defined by sweep geometry.
SectionedSpine | IfcSectionedSpine | If only the analytical shape is required for which the exact interpolation between the cross sections is not required, a sectioned spine can be used.
CSG | IfcCsgSolid |
Tessellation | IfcTriangulatedFaceSet |
MappedRepresentation | IfcMappedItem | All occurrences of IfcDistributionElement (and its subtypes) should (whenever possible) share a representation map established by the assigned type. The geometric representation of the occurrence is then an IfcMappedItem.
Table 118 — IfcJunctionBox Body Geometry

Exchange |  |  |  |  |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Import |  |  |  |  |  |  |  |  |  |  | R | R | R
Export |  |  |  |  |  |  |  |  |  |  | R | R | R

Classification

The Classification concept applies to this entity.

Exchange |  |  |  |  |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Import |  |  |  |  |  |  |  |  |  |  |  |  | R
Export |  |  |  |  |  |  |  |  |  |  |  |  | R

XSD Specification:

<xs:element name="IfcJunctionBox" type="ifc:IfcJunctionBox" substitutionGroup="ifc:IfcFlowFitting" nillable="true"/>
<xs:complexType name="IfcJunctionBox">
<xs:complexContent>
<xs:extension base="ifc:IfcFlowFitting"/>
</xs:complexContent>
</xs:complexType>

EXPRESS Specification:

ENTITY IfcJunctionBox

| SUBTYPE OF (IfcFlowFitting);

PredefinedType | : | OPTIONAL IfcStrippedOptional;

| WHERE

CorrectPredefinedType | : | NOT(EXISTS(PredefinedType)) OR (PredefinedType <> IfcJunctionBoxTypeEnum.USERDEFINED) OR ((PredefinedType = IfcJunctionBoxTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));
CorrectTypeAssigned | : | (SIZEOF(IsTypedBy) = 0) OR ('IFCELECTRICALDOMAIN.IFCJUNCTIONBOXTYPE' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType));

END_ENTITY;

Formal Propositions:

CorrectPredefinedType | : | Either the PredefinedType attribute is unset (e.g. because an IfcJunctionBoxType is associated), or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.
CorrectTypeAssigned | : | Either there is no junction box type object associated, i.e. the IsTypedBy inverse relationship is not provided, or the associated type object has to be of type IfcJunctionBoxType.

Inheritance Graph:

ENTITY IfcJunctionBox

| ENTITY IfcRoot

GlobalId | : | IfcGloballyUniqueId;
OwnerHistory | : | OPTIONAL IfcOwnerHistory;
Name | : | OPTIONAL IfcLabel;
Description | : | OPTIONAL IfcText;

| ENTITY IfcObjectDefinition

| INVERSE

HasAssignments | : | SET OF IfcRelAssigns FOR RelatedObjects;
Nests | : | SET [0:1] OF IfcRelNests FOR RelatedObjects;
IsNestedBy | : | SET OF IfcRelNests FOR RelatingObject;
HasContext | : | SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions;
IsDecomposedBy | : | SET OF IfcRelAggregates FOR RelatingObject;
Decomposes | : | SET [0:1] OF IfcRelAggregates FOR RelatedObjects;
HasAssociations | : | SET OF IfcRelAssociates FOR RelatedObjects;

| ENTITY IfcObject

ObjectType | : | OPTIONAL IfcStrippedOptional;

| INVERSE

IsDeclaredBy | : | SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects;
Declares | : | SET OF IfcRelDefinesByObject FOR RelatingObject;
IsTypedBy | : | SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects;
IsDefinedBy | : | SET OF IfcRelDefinesByProperties FOR RelatedObjects;

| ENTITY IfcProduct

ObjectPlacement | : | OPTIONAL IfcObjectPlacement;
Representation | : | OPTIONAL IfcProductRepresentation;

| INVERSE

ReferencedBy | : | SET OF IfcRelAssignsToProduct FOR RelatingProduct;

| ENTITY IfcElement

Tag | : | OPTIONAL IfcStrippedOptional;

| INVERSE

IsInterferedByElements | : | SET OF IfcRelInterferesElements FOR RelatedElement;
InterferesElements | : | SET OF IfcRelInterferesElements FOR RelatingElement;
ContainedInStructure | : | SET [0:1] OF IfcRelContainedInSpatialStructure FOR RelatedElements;

| ENTITY IfcDistributionElement

| INVERSE

| ENTITY IfcDistributionFlowElement

| INVERSE

| ENTITY IfcFlowFitting

| ENTITY IfcJunctionBox

PredefinedType | : | OPTIONAL IfcStrippedOptional;

END_ENTITY;

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