Curious Power Issue while using Chain Saw with Extension Cable!

sujsuj

I was trying to cut some wood using my RYOBI 2300W 40cm Chainsaw (RCS2340B). I used extension cables 13A rated its 25 meter long. But when I connect Chainsaw at end of extension cable power trips and Chainsaw stopped working. I could connect Chainsaw directly to plug and it works.

Both my extension cables are from ALDI/Workzone branded.  & Masteplug 

I could read from  online I need 'heavy duty' extension cable, not clear what specific rating I need to look out in the extension cable..? Since I already got  two 25m cables useless for this purpose, I want to make sure to buy the right one next time!  I can see Chainsaw's wire very thick compared to extension cable.  Please help. Thanks

TadleyBaggie

When you say the "power trips" is this a RCD or an MCB that trips?

Section62

sujsuj said:

I was trying to cut some wood using my RYOBI 2300W 40cm Chainsaw (RCS2340B). I used extension cables 13A rated its 25 meter long. But when I connect Chainsaw at end of extension cable power trips and Chainsaw stopped working. I could connect Chainsaw directly to plug and it works.

If it is the MCB tripping then there's a good chance the issue is the volt drop over 50m of low-cost extension cable is resulting in a current draw high enough to cause the MCB to trip.  What rating is the MCB, if it is that which is tripping?  (a photo may be best)

Why the picture of a Masterplug extension?  Are you using that one as well?

grumbler

Section62 said:

sujsuj said:

I was trying to cut some wood using my RYOBI 2300W 40cm Chainsaw (RCS2340B). I used extension cables 13A rated its 25 meter long. But when I connect Chainsaw at end of extension cable power trips and Chainsaw stopped working. I could connect Chainsaw directly to plug and it works.

If it is the MCB tripping then there's a good chance the issue is the volt drop over 50m of low-cost extension cable is resulting in a current draw high enough to cause the MCB to trip.  What rating is the MCB, if it is that which is tripping?  (a photo may be best)

This makes no sense. Higher cable resistance (and, as a result, higher voltage drop over the cable) can result only in lower current, that cannot cause MCB tripping.

Jonboy_1984

Are the extension cables fully unwound? They create additional resistance (and heat) when coiled due to the magnetic fields.

Jonboy_1984

Also what else is on the same circuit as socket, e.g. is it a kitchen socket with a washing machine, fridge, freezer etc on the same switch and what is the rating on the switch in the consumer unit?

There is a chance it’s the total load that’s exceeding the switch rating (I assume you are just running the saw rather than cutting anything when testing without the extension cables?).

grumbler

Jonboy_1984 said:

They create additional resistance (and heat) when coiled due to the magnetic fields.

I think, magnetic field is a myth as cable has two cores with opposite currents.

And, again, heat (poor dissipation in this case) on its own cannot cause MCB tripping

subjecttocontract

Could it be a faulty extension lead ? If plugging the chainsaw directly into the wall socket works ok and plugging it into the ext lead doesn't work ok.....the fault is with the ext lead surely ?

Keep_pedalling

grumbler said:

Section62 said:

sujsuj said:

I was trying to cut some wood using my RYOBI 2300W 40cm Chainsaw (RCS2340B). I used extension cables 13A rated its 25 meter long. But when I connect Chainsaw at end of extension cable power trips and Chainsaw stopped working. I could connect Chainsaw directly to plug and it works.

If it is the MCB tripping then there's a good chance the issue is the volt drop over 50m of low-cost extension cable is resulting in a current draw high enough to cause the MCB to trip.  What rating is the MCB, if it is that which is tripping?  (a photo may be best)

This makes no sense. Higher cable resistance (and, as a result, higher voltage drop over the cable) can result only in lower current, that cannot cause MCB tripping.

The saw is likely to compensate the lower voltage by drawing a higher current to compensate. 

I would not use a cheap extension lead for such a high current device. I purchased a heavy duty lead for my EV granny charger for holiday use from these guys. 

https://toughleads.co.uk/collections/ev-electric-vehicle-extension-leads

Section62

grumbler said:

Section62 said:

sujsuj said:

I was trying to cut some wood using my RYOBI 2300W 40cm Chainsaw (RCS2340B). I used extension cables 13A rated its 25 meter long. But when I connect Chainsaw at end of extension cable power trips and Chainsaw stopped working. I could connect Chainsaw directly to plug and it works.

If it is the MCB tripping then there's a good chance the issue is the volt drop over 50m of low-cost extension cable is resulting in a current draw high enough to cause the MCB to trip.  What rating is the MCB, if it is that which is tripping?  (a photo may be best)

This makes no sense. Higher cable resistance (and, as a result, higher voltage drop over the cable) can result only in lower current, that cannot cause MCB tripping.

Were you basing that on I = V / R  ....or something else?

FreeBear

I have a couple of large pieces of equipment that will trip an MCB when switched on - This is due to the very high instantaneous current draw on start up (big motors & large transformers). The answer for me was to swap out the standard domestic MCB for a type C.

Also have a mitre saw that will (sometimes) trip a 16A MCB, so I always plug it in to a 32A circuit.