Can I plug a treadmill into an extension cord (in Australia)?

[NJ1]

Hi!

Looking online, information was really mixed. So far as I can tell, the issues people have with treadmills and extension cords are because the US sells really low-grade cables that will literally melt if they overdraw instead of tripping, however, I was unable to find any Australia specific information and was hoping someone might know if this is possible. It's a walking pad designed to use under a desk, and yet it comes with a 0.5m cable that reaches nothing.

Heavy duty extension cables seem to come in 10A and 15A, but none are clear on the difference/where you would use one or the other, with the only hint I have being that all of the 15A cables are listed for caravans so I would assume not suitable for being plugged into a house.

There is this heavy duty extension cable:

https://www.bunnings.com.au/hpm-10m-1-5mm-10a-3-core-extra-heavy-duty-tradesman-extension-lead_p4420...

From what I can tell this could be suitable, but 10m is extremely excessive (I need less than 1m extension). Images attached of the info we have on the treadmill itself, 220-240V, 50/60Hz and 3.5HP, no mention on machine or in manual of amperage or wattage.

Thanks!

[JacobZ]

Hi @NJ1,

I am not an electrician, so I can't really comment on this kind of thing. Allow me to tag @CSParnell, @R4addZ and @MikeTNZ, who I know have knowledge of this sort of thing, to see if they can provide any insight. I believe @Dave-1 also has some experience with this sort of thing.

I suspect there would be no issues using something like this Arlec 1.8m Heavy Duty Extension Lead, which is much shorter than the 10m one you mentioned and includes an inline safety switch to help with overload protection.

Let's wait and see what the others say.

Jacob

[AlanM52 · Accepted solution]

Hi @NJ1,

I am not a qualified electrician, I am a qualified tradie in another sector of the trade.

I have a sound electrical background and... mixed in with other qualifications a Electrical Engineering degree. 

Technically that 3.5HP motor is equal to 2,611 watts and assume my answer is between 2600 and 2800 watts.

A domestic 240V/10A circuit delivers 2400 watts via your regular power point (P = E x I).

It's OK to plug the treadmill directly into a power point and usually I would recommend not using a extension lead but... in this this case it's OK to follow @JacobZ suggestion use the Arlec 1.8m Heavy Duty Extension Lead.

Cheers

[Dave-1]

Good Evening @NJ1 

No problems at all plugging into an extension cord The only time really that comes under question would be a super long one with something drawing a lot of current/power and by supper long I mean 25m upwards. (voltage drop, current and whats plugged into all come into play)

The equation @AlanM52 has used works well in explaining it technically, Australian rules are meant to be relied upon and if an extension cord is sold here then it must be able to satisy the rules. Most items will not draw over 10A . An 1.8m ext cord would be quiet satisfactory.

Click 2m White Extension Lead - 2m is what I would be buying and I have bought so many of these for running multiple things at work over the years.

Dave

[R4addZ]

Hi @NJ1 

Well speaking from experience, I have a full size treadmill and it is plugged into a 4 outlet powerboard  (the inexpensive ones they sell in bunnings) and dare I admit it, that powerboard is plugged into another powerboard each with about 1m cords on them! I would just make sure there is a trip device on it, but mine never has tripped.

[Nailbag]

Hi @NJ1 

When in the powertool game I used to have to deal with power ratings a lot when it came to generators, especially during times of natural disasters and the various requirements people had for urgently needing a generator. They often came back to Bunnings as quickly as they went out as customers simply had no concept of how to match one up to the power needs. It can be quite complex.

There is not just the power requirement of the treadmill, there is also the startup power requirement of the motor. This is the power they require when first turned on. The two likely motors in the treadmill will be a standard brushed or its most likely an induction. The later requires far greater power at startup. So, even if the running power is under the power outlets capacity, the startup could trigger a circuit breaker trip. Looking just at the 3.7Hp as running power; 

A domestic household 10A outlet can handle a maximum of 2,400W, while a 15A can handle a maximum of 3,600W. 10A and 15A extension cords have the same power ratings. But will loose voltage once you start getting up to 20m+ lengths. Depending on the brand/model of power board, they have a max rating of 2,400W for the total number of outlets.

1Hp = 746W. So dividing 2,400W (for a 10A outlet) / 746  = 3.21 Hp. Factoring that the treadmills 3.7Hp rating is when it's running at high-speeds, still puts it over the limit for use inside the home as it will causing the circuit breaker to trip at those higher speeds. And again this doesn't factor in any start up power requirement. So in short you will need an outlet wired by an electrician for 15A as this would provide 4.8hp at all speed settings.

An electrician will also be able to 100% confirm its maximum running power as it is possible that the 3.7hp is over-rated to its actual. It's not uncommon for some manufactures to deliberately do this in order to say their product is more powerful than a competitor/s. In which case it may end up being ok to run off your standard power outlet.

And the reason there is no mention of watts in the manual is typical of US electrical products as they use HP or more often Amps to represent the products power.

Nailbag

[NJ1]

Thanks for all the advice!

We did test the treadmill direct into an outlet so we could tell if it was actually going to run within a reasonable warranty timeframe, and it all worked perfectly on initial startup and at the highest speed we would ever use (max speed is a whopping 12km/h and this is not for running so we will never use it above 5-6km/h), so I think it unlikely we will run into any issues that would require a 15A outlet as @Nailbag suggested. The advice here seems to boil down to:

• In Aus any well-made extension cord should be able to run this treadmill, just maybe not at max draw which we will likely never achieve @JacobZ @AlanM52 @Dave-1 
• The shorter the better to reduce/eliminate voltage loss @Dave-1 @Nailbag 
• Given the startup success on a standard 10A outlet, we shouldn't have any issues/use case where 15A would be required @Nailbag 

The treadmill itself has a safety trip, but we're gonna go with the heavy duty Arlec cord both because it's a bit shorter than most, and has it's own safety switch just in case.

Thanks again for all the help!

[Nailbag]

Hi @NJ1 

You're welcome for the advice. Just note the treadmills safety trip will most likely nothing to do with the supply power, but an internal issue. For example of the belt was jammed causing the motor to overload. the safety switch/circuit breaker on that Arlec extension will be the one protecting input supply.

Nailbag