Revit Guides
Data Management
ELI5
Junction Boxes
Junction Box Requirements in Electrical Installations To ensure compliance with BS 7671:2018+A2:2022, the following requirements apply when using junction boxes in electrical installations: 1. Compliance with BS EN 60670-22 Any
BIM Stages
ELI5-S1:BIM Basics: E13_Understanding BIM Stages Understanding BIM Stages: Transitioning from BIM Levels to a Modern Framework In the world of Building Information Modeling (BIM), we often come across terms like
VEAM connector
VEAM connectors refer to a specific type of electrical bayonet type connectors known for their robustness and reliability in harsh environmental conditions. These connectors are commonly used in various industries,
BIM Levels
The transition from the BIM Levels to the concepts in the ISO 19650 series and the UK BIM Framework represents a shift in how we think about BIM maturity. However,
VADs
Guide to Visual Alarm Devices (VADs) in Fire Safety In high-noise workspaces or locations requiring hearing protection, Visual Alarm Devices (VADs) play a critical role in fire safety. They ensure
Young Person
The term “Young Person” in the context of construction, Building Information Modeling (BIM), electrical engineering, or general engineering typically refers to a younger individual, often a recent graduate or entry-level
x-ref
The term “X-ref” is commonly used as an abbreviation for “External Reference” in various technical and engineering fields, including construction, Building Information Modeling (BIM), and computer-aided design (CAD). Here’s a
zone indicator
part of indicating equipment which visually indicates the zone of origin of a alarm of fire or faultwarning BS 4422 2005 Zone Indicator in Fire Alarm Systems The zone indicator
jet reaction
nozzle reactionforce acting in the opposite direction to the water stream leaving the nozzle BS 4422 2005 “Jet reaction,” also known as “nozzle reaction,” is a fundamental concept in fluid
jet
extinguishing medium, usually water, leaving a nozzle as a continuous stream, water spray, or waterfog (mist) BS 4422 2005 Each of these methods has its own advantages and is chosen
Exchange Information Requirements (EIR)
The Exchange Information Requirements (EIR) term introduced by BS EN 19650 replaces the PAS 1192 term Employer Information Requirements (EIR) on all projects where BS EN ISO 19650 compliance is
coordination
execution of workflow in the correct sequence managed by the competent project team members working together to achieve common, albeit often multifaceted goal. Coordination often involves more than one party
Ze
That part of the earth fault loop impedance which is external to the circuit under consideration. For the supply cable it will be the impedance external to the installation. For
Z2
Z2 – That part of the earth fault loop impedance which comprises the impedance under earth fault conditions of the circuit protective conductor (cpc) of the circuit under consideration.
Z1
Z1 – That part of the earth fault loop impedance which comprises the impedance under earth fault conditions of the line conductor of the circuit under consideration.
Uninterruptible power supply (UPS)
An uninterruptible power supply (UPS) is used to maintain the supply to an essential service duringmains supply outages. On loss ofmains supply,a storage device in the UPS (battery) continues to
Nominal line voltage to earth (Uo)
Uo Nominal line voltage to earth. Assumed to be 230 V for grid connected systems.
TT system
A system having one point of the source of energy directly earthed, the exposedconductive-parts of the installation being connected to earth electrodes electrically independent of the earth electrodes of the
TN system
A system having one or more points of the source of energy directly earthed, the exposedconductive-parts of the installation being connected to that point by protective conductors.
Subject to Simultaneous Overload
Where circuits are grouped, there are two availablemethods of calculating the rating factor Cg to be applied: [BS7671:2018,Appendix 4,5.1.2:Equation 2] [BS7671:2018,Appendix 4,5.1.2:Equation 3,4]
Soil Thermal Resistivity
Relates to the ability of the soil, in which the cable is installed, to conduct heat energy away from the cable. The rating factor Cs is applied in cable sizing
Residual Current Device (RCD)
AResidual Current Device (RCD) is amechanical switching device or association of devices intended to cause the opening of the contacts when the residual current* attains a given value under specified
Rating factors
Rating factors are divided into the nominal rating of the circuit protective device (In) to determine theminimum current-carrying capacity (Iz) of a cable in a circuit. For example:Iz = In/(Ca
Rated current
Value of current used for specification purposes,established for a specified set of operating conditions.
Power factor
Power factor is the ratio of the resistance (R) and impedance (Z) in a circuit, that is:Power factor = cos ∅ =R/Z
Max Zs
Themaximum value of earth fault loop impedance (Zs) that will allow the protective device in a circuit to disconnect an earth fault within the prescribed time. Example: if themaximum earth
k Factor
Factors for conductor materials from BS7671:2018,Table43.1. Different values are given for different types of conductor and insulatingmaterials. k2s2 used in adiabatic calculations gives the short-time withstand of a conductor in
Current carrying capacity of a cable (Iz)
Iz The current carrying capacity of a cable under the defined installation conditions. This is the effective rating of the cable after the relevant rating factors have been applied, i.e.,Ca,
Overload rating (Ir)
Ir The adjusted overload rating of an overcurrent protective device, in Amperes.
Prospective fault current (Ipf)
Prospective Fault Current (Ipf) is the value of overcurrent at a given point in a circuit resulting from a fault of negligible impedance between live conductors having a difference of
