# Short-Questions

Fast solutions for complex problems

## What is the space factor for conduit system?

F or 38mm conduit use the 32mm factor x 1.4. For 50mm conduit use the 32mm factor x 2.6. For 63mm conduit use the 32mm factor x 4.2.

## What is the space factor of cable tray?

A: According to The Cable Tray Institute, an association of companies involved in the development of cable-tray systems, 9 inches is the most common rung spacing for ladder cable tray, which may be used to support all sizes of cables.

How do you calculate cable factor for conduit?

Calculations:

1. As per Table Cable Factor for 1.5 Sq.mm Stranded Cable=8.1.
2. As per Table Cable Factor for 2.5 Sq.mm Stranded Cable=11.4.
3. As per Table Cable Factor for 2.5 Sq.mm Stranded Cable=22.9.
4. Total Cable Factor= No of Cables X Cable Factor.
5. Total Cable Factor=(30X8.1)+(50X11.4)+(20X22.9)
6. Total Cable Factor=1271.

What are the factors affecting the choice of wiring system?

The choice of wiring system is affected by many factors such as the type of building, temperature, safety, cost, etc. The electrician needs to be able to decide upon the most suitable type of cable or wiring for a given situation.

### How many wires can run through conduit?

Allowable Conduit Fill Capacities

Size and Type of Conduit 14 AWG Wire 8 AWG Wire
1-inch EMT 35 9
1 1/2-inch EMT 84 22
1/2-inch PVC—Sch 40 11 3
3/4-inch PVC—Sch 40 21 4

### How do I choose a trunking size?

To determine the trunking size needed, multiply the quantities of each cable by the appropriate factor, and compare the total with the trunking capacity figures shown. For example: What size of standard trunking is needed for 10 in number 35mm² cables and 16 in number 4mm² cables?

How is cable trunking size calculated?

What is the difference between cable tray and cable ladder?

Generally, cable ladders are preferred for supporting high volume or heavy cabling, especially if there are long spans between supports. Cable trays are typically used for light weight cable support, in addition to instrumentation and tubing.

#### What are the methods of wiring?

Basic Wiring Methods

• Cleat Wiring. Here, PVC insulated cables are used.
• Casing and Capping Wiring. The cable runs through a wood casing that has parallel grooves that appear at regular intervals along it.
• Batten Wiring. Batten wiring is one of the basic wiring methods that is used today.
• Conduit Wiring.

What are wiring systems?

Electrical wiring is defined in the IET Wiring Regulations (BS 7671) as ‘wiring systems’, with the following definition: ‘An assembly made up of cable or busbars and parts, which secure, and if necessary, enclose the cable or busbars. ‘

How many wires can fit in a 2 inch conduit?

Trade Size Wire Size (THWN, THHN) Conductor Size AWG/kcmil
1
2 EMT 8
IMC 9
GRC 8

## Can You overfill a conduit above the space factor?

Everyone knows there was very little danger that the motorists could have caused by them using the bus lane – neither if you overfill a trunking above the space factor if no overheating of cables should occur (it’s not meant to be a comparison).

## What is the IEE regulations on space factors in conduits and ducts?

This topic is covered in the IEE’s On-Site Guide, a supplement to BS 7671:2008 Regulations for Electrical Installations. ‘Grouping’ describes to the mutual heating effect of adjacent conductors.

Is the conduit full of cable no space?

Conduit – full of cable – no space at all. I’ve seen this at brand new installatiosn and older ones. I was more concerned about older installations where trunking is full due to new circuit additions.

When to use conduit drops and multi compartment trunking?

Conduit drops are then used to supply outlet points. Multi-compartment trunking is used where different electrical services are required in close proximity to each other. It is ideal in large offices and classrooms. Here it may be used to accommodate cables for supplying equipment at 230 Volts, plus data cables for computers, printers etc.