The calculator below will allow you to select the appropriate cable size for your outdoor lighting system.

Finding the technical information you want is often harder than it should be. To help you find 'what you need, when you need it', we’ve developed this online resource containing useful Standards, Charts and Calculators. And remember if it’s not here our in-store experts are always happy to answer any technical queries you may have.

Load Class
A
Extra Light Duty

Traffic

Areas (including footways) accessible only to pedestrians and pedal cyclists and closed to other traffic

Serviceability Design Load (kN)

6.7

Ultimate Limit Design Load (kN)

10

Nominal Wheel Loading (kg)

330

Load Class
B
Light Duty

Traffic

Areas (including footways and light tractor paths) accessible to vehicles (excluding commercial vehicles) or livestock

Serviceability Design Load (kN)

53

Ultimate Limit Design Load (kN)

80

Nominal Wheel Loading (kg)

2,670

Load Class
C
Medium Duty

Traffic

Malls and areas open to slow moving commercial vehicles

Serviceability Design Load (kN)

100

Ultimate Limit Design Load (kN)

150

Nominal Wheel Loading (kg)

5,000

Load Class
D
Heavy Duty

Traffic

Carriageways of roads and areas open to commercial vehicles

Serviceability Design Load (kN)

140

Ultimate Limit Design Load (kN)

210

Nominal Wheel Loading (kg)

8,000

Load Class
E
Extra Heavy Duty

Traffic

General docks and aircraft pavements

Serviceability Design Load (kN)

267

Ultimate Limit Design Load (kN)

400

Nominal Wheel Loading (kg)

13,700

Load Class
F
Extra Heavy Duty

Traffic

Docks and aircraft pavements subject to high wheel loads

Serviceability Design Load (kN)

400

Ultimate Limit Design Load (kN)

600

Nominal Wheel Loading (kg)

20,000

Load Class
G
Extra Heavy Duty

Traffic

Docks and aircraft pavements subject to very high wheel loads

Serviceability Design Load (kN)

400

Ultimate Limit Design Load (kN)

600

Nominal Wheel Loading (kg)

20,000

Selecting an appropriate cover or grate also depends on the where it will be installed and the various types of traffic that it may receive. Whilst load classifications provide a guide, nominal loads are based on stationary loads, which poorly simulate real world traffic conditions.

Also Consider

Dynamic Loads

Areas subject to moving traffic will exert a dynamic load which will try to twist a cover out of position. If traffic moves quickly or turns on a cover, a higher load class should be selected and extra design features should be sought such as slotted drainage, locking grates down with bolts or steel reinforcement.

Small or Solid Wheels

Small or solid wheels concentrate a heavy load to a very small point where it is transferred to the cover. This can be the case with forklifts and rubbish skips which often feature solid wheels and cause massive damage to underspecified covers. A grate or cover with a higher load class will be required in these situations.

Large or Pneumatic

Large or pneumatic wheels will spread a load over a larger area and exert a lower stress on the grate or cover. This is why a heavy tractor can be classified in load class B with smaller vehicles.

Areas at the base of a steep decline

Covers at the base of a decline will experience short periods of increased load as a large portion of the vehicles total weight can be transferred to the front wheels. The cover will be under high stress and a higher load class will be required in these situations.

Notes

1. Nominal wheel loads are given for guidance only. Consideration should be given to the type, size and pneumatic pressure of the load applied.
2. Class B design loads exceed AS 5100.2 requirements for footway loading.
3. Class D design loads exceed AS 5100.2 requirements for a W80 wheel load.
4. Class C units are based on an intermediate load.
5. The serviceability load is set at 2/3 of the ultimate limit state design load.
6. A force of 1 kN approximately equal to the weight of 100 kg.