Hot tub - 2 core or not 2 core

[ban-all-sheds]

I came here to look for advice before I pay hundreds for a jack hammer, or pay hundreds for a sparky.

But not before you decided to go ahead designing and installing a circuit despite not knowing how to do it.

 

[winston1]

The American local distribution system is often three phase HV ( 11Kv or more ) feed on poles along the street with tin can transformers hung from the poles. Each tin can provides providing an LV (110 v) to one or two houses. There is seldom an Earth ( or grounded ) conductor along the pole route and if there was it would be related to the HV supply and thus not suitable for providing Earth ( or Ground ) for the LV supplies to the houses.

120 volts not 110v. In fact it is centre tapped 240 volts supplies with most circuits using one side. The full 240 volts is used for heavy loads.

 

[bernardgreen]

120 volts not 110v

Please do some research and then come back

Hint ... consider the number 117 in your research.

 

[Taylortwocities]

120v AC is the 'nominal' voltage in the USA and Canada (±5%).
A bit like the 'nominal' voltage here is 230v

Seems like Winston accepts the concept of a nominal voltage in the colonies, but not here in good old blighty.

 

[winston1]

Please do some research and then come back

Hint ... consider the number 117 in your research.

I have researched it. US voltage is 120V plus or minus 5%, i.e. 114v to 126v. 110v is outside this range. 117v is the estimated voltage at the outlet after volt drop from the local transformer.
Last time I was in NY I measured the voltage at 123v.

 

[winston1]

120v AC is the 'nominal' voltage in the USA and Canada (±5%).
A bit like the 'nominal' voltage here is 230v

Seems like Winston accepts the concept of a nominal voltage in the colonies, but not here in good old blighty.

The US "nominal" voltage is true.
The UK "nominal" voltage is a fudge, it is still 240v in practice.

The US is an independent country not a colony.

 

[JohnW2]

I have researched it. US voltage is 120V plus or minus 5%, i.e. 114v to 126v.

Indeed.

110v is outside this range.

Indeed it is - so why all the talk we see (and there is a lot of it) about "110 V". Was that perhaps the nominal voltage at some point in the past, or what?

Kind Regards, John

 

[bernardgreen]

Was that perhaps the nominal voltage at some point in the past, or what?

Yes it was 110 volts. Then it was increased to 115, and then up to 120 +/- 5% as the supply voltage that should be supplied to the house. Most of the independent power supply companies did increase the supply voltage but some did not and continued to supply at 110 volts. Some towns with their own independent generating company refused to accept 120 and their local generator remained supplying at 110.

I will accept that in the past few years some of these rebels may have come into line and changed to suppy at 120 volts.