Daisy chain extension reels

aslco · 30 Jul 2017 at 09:47

Hi I have an outbuilding 60 metres away from the nearest power outlet on my house. I want to use an angle grinder to do some pointing. I already have a 13amp 40m extension reel with inbuilt thermal cut off and an 18m equivalent. If I put an RCD in the outlet first should I be ok to use just one 750 watt titan angle grinder off them if I daisy chain them?

Main risks seem to be heat and voltage drop, but I think with them fully unreeled and thermal cut off engaged and with just the one device running for brief periods of time it should be ok?

NoobCannon · 30 Jul 2017 at 10:56

For a temporary purpose i dont see why not

Lumeycom · 1 Aug 2017 at 15:53

Absolutely fine. Fag packet maths suggests a 4v drop with that small load and assuming your extensions are 1.5mm cable.

a1ex2001 · 1 Aug 2017 at 16:16

Permanent installation no but for this job no issue at all like you say unroll them to be on the safe side

Orionaut · 1 Aug 2017 at 16:19

Resistive Heating will not be an issue provided the reels are fully unwound, regardless of how many daisies are in the chain. Resistive voltage loss might be. However most normal power tools use universal motors which are pretty tolerant of voltage drop.

However, If you are ever intending to use anything with an induction motor that is rated at the maximum 13 amps (Say, a 3Hp compressor) you "Might" run into issues. Induction motors do not like running at reduced voltage and the voltage doesn't have to be "That" far below rated voltage and they will not start with a load attached and may also run hot even if they do start.

aslco · 1 Aug 2017 at 22:14

Great thanks. I think it is actually 1.25mm cable but hopefully that's still ok

Lumeycom · 2 Aug 2017 at 10:55

aslco said:
Great thanks. I think it is actually 1.25mm cable but hopefully that's still ok

7v (ish) drop - still no issue that I can see. You'll be fine just unreel them all and be sensible (and check the rcd works of course)