Westinghouse WHXC3750, Instruction Manual

26 

OPERATION

power demand or more. Manufacturers of such devices 

rarely publish this starting power demand and so it’s 

often necessary to estimate it.

A rule of thumb for devices fitted with an electric motor 

is to apply a starting power multiplier of 1.2 for small 

hand-held or portable devices and a value of 3.5 for 

larger stationary devices. For example, a 900 W angle 

grinder can be assumed to have a starting power 

demand of at least 1.2 × 900 W, which equals 1,080 W. 

Similarly, a 1,650 W air compressor can be assumed 

to have a starting power demand of at least 3.5 × 

1,650 W, which equals 5,775 W.

To prevent overloading of the generator’s 240-Volt AC 

system:

1.  Add up the running power demand of all the 

240-Volt AC devices that will be connected to 

the generator at one time. This total must not be 

greater than the generator’s specified running 

power output.

2.  Add up the running power demand again, but for 

the largest motor-driven device use the value of 

its starting power demand instead of its running 

power demand. This total must not be greater than 

the generator’s specified starting power output.

3.  The total running power demand of all the 

devices that will be connected to any one of the 

generator’s outlets must not exceed 3,000 W for 

the WHXC3750 and WHXC3750-PRO models or 

3,600 W for the other models.

The above guidelines serve as approximations only of 

determining the running and starting power demands 

of 240-Volt AC devices. If in doubt, always err on the 

conservative side to avoid overloading the generator. 

In the absence of any power demand information 

whatsoever, one can assume that any device fitted 

with a standard domestic 10 A plug has a running 

power demand of 2,400 W (i.e. 240 V x 10 A = 2,400 

W). Similarly a device fitted with a heavy duty 15 

A plug can be assumed to have a running power 

demand of 3,600 W (i.e. 240 V x 15 A = 3,600 W). 

And then apply the appropriate multiplying factor for 

starting power demand if the device has an electric 

motor.  

NOTICE

To prevent overloading of the generator’s 12-Volt DC 

system, do not connect any 12-Volt DC device(s) 

with a running power demand greater than 100 W.

240-Volt aC EXtEnsion 
CorDs

Wherever possible, it is recommended to connect 240-

Volt AC devices directly to the generator’s 240-Volt AC 

outlet(s). This ensures that the device is supplied with 

the best quality electricity.
In those instances where it’s not practicable or safe to 

directly plug an electrical device into the generator, the 

use of an electrical extension cord is necessary.

1.  Use only the shortest possible extension cord for 

the task. Voltage drop increases proportionately 

with the length of an extension cord and may 

result in damage to the powered device.

2.  Use only a single extension cord and not multiple 

cords joined together. This will minimize voltage 

drop and prevent any hazard or inconvenience 

arising from the joint(s) becoming disconnected.

3.  Use only extra heavy duty 15 A extension cords 

made from 3-core cable of at least 1.5 mm

2

conductor size and fitted with 15 A plugs and 

sockets (see Figure 23). A 15 A plug cannot be 

inserted into a standard domestic 10 A socket.

4.  Extension cords with conductor size of 1.5 mm

2 

or 2.5 mm

2 

should not exceed 31 m or 51 m in 

length, respectively, in accordance with AS/NZS 

3000:2007.

NOTICE

DO NOT use standard 10 A extension cords fitted 

with standard domestic 10 A plugs and sockets. 

These do not have sufficient current carrying 

capacity, which will result in excessive voltage drop. 

10 A extension cords may overheat and possibly 

catch fire if overloaded when connected to the 

generator’s 240-Volt 15 A outlets.

NOTICE

DO NOT use extension cords with only 2-pin (active 

and neutral) plugs and sockets. These extension 

cords lack the earth connection that is provided by a 

3-pin plug and socket joined with a 3-core cable; the 

vertical pin is the earth connection.

5.  The extra heavy duty 240-Volt AC 15 A outlets 

on the WHXC3750-PRO and WHXC8500E-PRO 

models can be used with extension cords fitted 

with Clipsal 56-Series (or equivalent) plugs to 

achieve a weatherproof IP66 and thread-secured 

electrical connection.

6.  DO NOT use extension cords with any visible 

signs of damage to the plug, socket or cable.

7.  DO NOT use extension cords that are rolled up or 

knotted as they may overheat.