John Harold asked in Science & MathematicsPhysics · 11 months ago

# Is it okay to use two power extension cords connected to each other?

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• John P
Lv 7
10 months ago

In general, yes, but you need to think about a couple of things.

Voltage drop over a long total cable length - no worries for a computer or TV, but important for kettles and heaters.

The danger of connecting too many devices if each cable has multiple outlets.

Also the danger of water and electricity coming into contact if you are using the extensions outdoors. Wrap the junctions in plastic bags etc.

All in all, maybe get local advice from somebody who really knows about electricity concerning the particular set-up which you want to use.

• 11 months ago

Sure it is.

• 11 months ago

It is "sort of" OK.

Consider two 3 m cords in series. 6m long. Now there is some resistance in the plug but it still has less resistance than a single 10m cord.

The limit to the length is to do with the power drop.

I live on a farm and the wires leading to me drop 10 V for every kw I consume.

so if I use a welder the volts drop from 245 down to 215 approximately.

If I use a 20 m cord I lose another 15 volts. Now I am only getting 200 v

Now the amount of loss depends on the amount of current being used.

So if you have a low drain thing like a light bulb you could have 200 m or more of power cord with minimal loss.

As you increase the power required the losses mount quickly.

The formula is P = i^2 R

or for the volts lost V = iR

Which means that if you have a cord that is working fine on a 2kw device then you could use 2 of these in series on a 1kw device for the same loss of power.

It is quite safe IF you make sure that you only use it for lower current/load.

If you really need higher current and load over a longer distance then you need to purchase a much higher rated cord which has more copper in it and is very expensive.

• goring
Lv 6
11 months ago

Electric cords are rated by the amount of power they can carry with a minimal voltage drop at a particular length

if the length is exceeded an over voltage drop can occur and the motor at the other end wont be able to start..

• Vaman
Lv 7
11 months ago

No problem. Do not connect them in series. The voltage will be doubled and your equipment will get burnt. You can connect them in parallel.

• 11 months ago

It can be. It is always better to use one that is designed to go the distance than to chain two. It should not be a problem, but any link is a weaker point that a direct wire. a potential point of exposure to a short or something.

As long as you do not exceed the capacity for power of the weakest cord, you should be all right.

• R K
Lv 7
11 months ago

yes

• Stacie
Lv 4
11 months ago

Yes, completely okay.