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Electrical formula examples: power outlets, mains cable runs and air conditioning

Dive into example electrical formula.

Updated this week

Before reading this article, ensure you have read Measurement - parts & labour and Using formula within Groundplan articles to aid in understanding the following formula examples.

📝The formula values provided in this article are for example purposes only.

Term

Explained

count

total counts

len

total metres measured

area

total square metres measured

count, len or area / x

total count/length/area divided by an amount

count, len or area * x

total count/length/area multiplied by an amount

ceil(x)

rounding up a decimal value to the next whole number

Double GPO (double power outlet)

Example parts for a double GPO (double power outlet) count measurement:

Part

Explanation

Formula

UoM

Double GPO

Double GPOs counted

count

each

Wall bracket

Allowing for a wall bracket for each double GPO

count

each

2.5mm twin and earth

How many metres are required when 12m are allowed with each double GPO

count*12

m

2.5mm twin and earth (100m cable drum)

How many metres are required when 12m are allowed with each double GPO divided by a 100m drum

count*12/100

drum

2.5 cable clips

How many clips are needed when 5 are required for each double GPO divided by a jar of 500

count*5/500

jar

LABOUR

Labour

Allowing for 30 minutes of Labour for every double GPO counted as per the Labour Conversion Chart

count*0.5

hours

Mains Cable Run

Example parts for a mains cable run length measurement:

⚠️Warning: This example does NOT use the height component in the measurement unit section:

Part

Explanation

Formula

UoM

Mains cable runs

How many metres are required

len

m

50mm HD conduit (orange rigid 4m)

How many 4m lengths of conduit required for the length measured

ceil(len/4)

lengths

16mm XLPE Four Core

How many total metres required and allowing for an additional 4m per run measured to the switchboard

len+count*4

m

16mm SDI red cable (S/D insulated)

How many total metres measured multipled by 3 lengths of cable required and allowing for an additional 4m per run (making 12 in total for the 3 lengths) measured

len*3+count*12

m

16mm SDI black cable (S/D insulated)

How many total metres required and allowing for an additional 4m per run

len+count*4

m

Warning tape underground orange (100m)

How many 100m rolls of tape required for the length measured

len/100

rolls

50mm sweeping bend (90° heavy duty orange)

Number sweeping bends required multiplied by 2

count*2

each

LABOUR

Labour

Allowing for 10 minutes of Labour for every metre measured as per the Labour Conversion Chart

len*0.17

hours

Airconditioning / Heat pump

Example parts for a 2.7m height ceiling airconditioning area measurement. This formula is based on an m² calculation.

⚠️Warning: This example does NOT use the height component in the measurement unit section:

Part

Explanation

Formula

UoM

Room areas

How many metres squared for each room measured

area

KW rating

Area measured multiplied by 150 wattage per m2 and to convert to a KW rating, divided by 1000

area*150/1000

KW

Volume of air

The area measured multiplied by 2.7m ceiling height

area*2.7

View individual KW ratings quantities when exporting

To show individual area KW ratings, lock the breakdown to display on export. It is recommended to rename the areas within the stage to display the location.

  1. From the quantities tab, click + on the part / labour line with the breakdown

  2. Click + next to KW Rating and click the padlock

  3. Click export and select export as CSV

  4. Choose the export format

    View the breakdown in the notes column or for group by measurement, the breakdown will appear in the description column

  5. Click download export


For formula assistance, please reach out to Support. Go to: Help > Send us a Message.


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