Table of contentsNo headers
- Revit MEP
Use the Wiring Types table to specify the wire types that can be used in your project. You can add or remove wire types as needed. Multiple wire types can be specified for a project. The first entry specified in the wire types table dialog is the default wire type used for circuits created in the project. This should be the wire type used for the majority of the wiring in a project. You can select a different wire type for a circuit on its Properties palette.
The fields in the Wiring Types table are as follows:
- Name - This is a user-defined string that identifies a particular wire type.
- Material - Copper, Aluminum, or a project specific material as defined in the New Material dialog.
- Temperature Rating - 30C, 60C, or 95C, or a project specific temperature rating as defined in the New Temperature dialog.
- Insulation - Depending on the material selected, several insulation types can be specified, including a project specific insulation as defined in the New Insulation dialog.
- Max Size - This is the maximum conductor size to be used when sizing wires of this type from 14 to 2000 MCM (thousand circular mils). This parameter lets you control when wires start being sized in parallel runs rather than by simply increasing the wire size until 2000 MCM is reached.
- Neutral Multiplier - Using this field, in combination with the next two fields, you can specify how the neutral conductor of a system will be sized. The value specified here is used to increase or decrease the calculated size of the neutral conductor based on a multiplier of the conductor’s size. Similar to the way that ground conductors are oversized for voltage drop situations, the neutral conductor can be sized to be larger than the calculated size.
The neutral multiplier is applied to the neutral conductor based on cross-sectional area rather than ampacity. It is intended to handle the current increase that results from harmonic loads. Harmonic loads are caused by switching the power supplies found in many types of electronic equipment. These switching power supplies create harmonic distortion in the current waveform and cause current to flow at a higher value than would be expected in an electrical system.
The Neutral Multiplier is applied after the neutral size is calculated, either by sizing the same as the hot conductors or according to unbalanced current.
- Neutral Required - If selected, all wiring runs using this wire type must include a neutral, even in the case of a balanced 3-phase load, where a neutral may not be required by the load itself.
- Neutral Size - In this field you can specify whether the neutral is sized by Hot Conductor Size (the baseline for the size of the neutral will be the same as the hot conductor) or by Unbalanced Current (the neutral will be sized based on the amount of current flowing in the neutral).
- Conduit Type - Conduit material affects the impedance of wire and determines what portion of the wire impedance table is used for the voltage drop calculations. Click the value, then select either Steel or Non-Magnetic.