Help with cable and mcb calcs

[Bishee1999]

We have 6 400watt lights in a garage.

Please can anyone help me with a formula to work out cable size and the breaker size.

Thanx

 

[Bishee1999]

Sorry the max length of cable run is 30 mteres on a single phase supply

 

[ban-all-sheds]

We have 6 400watt lights in a garage.

Sounds rather a lot for a domestic garage - what is the place?

Please can anyone help me with a formula to work out cable size and the breaker size.

• http://www.diynot.com/wiki/electrics:mcbtocable
  
  
• http://www.tlc-direct.co.uk/Book/4.3.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/4.3.11.htm
  
  
• http://www.tlc-direct.co.uk/Book/5.3.1.htm
  
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/cableselection_web.pdf
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  

 

[Bishee1999]

Sorry i meant a commercial garage with domestic circuit ie single phase

 

[ban-all-sheds]

commercial garage

Electricity At Work Regulations.

Public Liability Insurance Ts'n'Cs.

Employer's Liability Insurance Ts'n'Cs.

Buildings Insurance Ts'n'Cs.

Lease agreement Ts'n'Cs.

Stay away from the electrics.

 

[Taylortwocities]

What cable and breaker size are you asking about?

The wiring within the garage?

or do you mean the cable that feeds the garage from the incoming supply?

 

[ricicle]

commercial garage

Electricity At Work Regulations.

Public Liability Insurance Ts'n'Cs.

Employer's Liability Insurance Ts'n'Cs.

Buildings Insurance Ts'n'Cs.

Lease agreement Ts'n'Cs.

Stay away from the electrics.

What he said ^^^^ plus Atex considerations depending on the locations

 

[viewer]

To add to BAS' list, you need to consider hazardous areas and petroleum (regulations). Really a specialist area.

 

[dingodeano]

We have 6 400watt lights in a garage.

Please can anyone help me with a formula to work out cable size and the breaker size.

Thanx

Ib <= In <= Iz

 

[PrenticeBoyofDerry]

We have 6 400watt lights in a garage.

Please can anyone help me with a formula to work out cable size and the breaker size.

Thanx

Ib <= In <= Iz

Also calculations for any simultaneous occurring factors, voltage drop and ref method.

 

[Spark123]

A 400w discharge light needs a correction factor of 1.8 applied to it to work out the design current also.
There's also stroboscopics to consider where you have moving machinery and discharge lights.

 

[RF Lighting]

400W fittings sound like they'll be discharge lights so there's going to be inrush current to think about when selecting not only the cable size and OCPD size and type, but the functional switching too.