Electrical Advice

[JPG]

I would say it draws less than rated amperage when it is delivering less than rated horse power. It draws several times 13 A at startup(briefly).

[dusty]

I would say it draws less than rated amperage when it is delivering less than rated horse power. It draws several times 13 A at startup(briefly).

I'm not sure what you are referring to when you say 'it is delivering less than rated horse power" but I am saying that a typical Mark V (in operating condition) draws only 7-8 amps except at startup. During startup it momentarily draws about 20amps but for a very, very short period of time. I have metered this complete with a video and posted the details before.

There is a post here on the forum with a UTube video that shows the meters throughout a turn on cycle.

This is one of the reasons why a differ with those who claim that the Mark V should be operated on a 20 amp breaker.

[JPG]

When the motor is running with no mechanical work being done, it is not delivering rated horsepower. When a mechanical load(sawing, planing, jointing etc.) the current will increase with the increase in output work being done.

I agree 1 15A branch circuit is adequate IF not much else is connected to it.

However 15A branch circuits are wired with #14 gauge wire.(unless a very long run).

The advantage of a 20A branch circuit is that other things(Dust Collector?) can be run off it. AND the wires are #12 which decreases the voltage drop at startup.

Do remember the 1 1/8 hp motor was originally created in the early 60's. Mostly 15A house wiring and many with fuse boxes.

IIRC Dennis's current measurements with a recording scope far exceeded 20A at initial startup.

[BuckeyeDennis]

IIRC Dennis's current measurements with a recording scope far exceeded 20A at initial startup.

Yup. A bit over 50 Amps RMS, when the motor is first starting to spin up.

https://www.shopsmith.com/ss_forum/view ... p?p=189434

[everettdavis]

I know there is much to be said about wire size, connectors, dedicated circuits, dedicated isolated circuits, switch contacts, motor start relay or motor start centrifugal switch contacts, condition of the receptacle, interior wiring, and the circuit breaker.

Currently homes in our area are permitted to use 14 gauge wire on lighting circuits only, and 12 gauge on outlets.

With a Shopsmith driven planer, there is a noticeable difference 12 AWG and 20 A Dedicated Isolated circuit.

I do not have a dedicated isolated 14 gauge circuit with a 15 A breaker to compare it to. I would dare say 14 gauge circuits with 15 A breakers are likely not present in most older homes.

My comment was if you do as I recommended, You will not have those sorts of power problems on your Shopsmith 110v models. Period.

You can also alternately run that large 110v air compressor, or 110v welder on that circuit as well. I dedicate every circuit I can in the shop.

My compressor and welders are both 220, so they have the proper circuits dedicated already.

Everett

All I am offering is the truth Nothing more.png (267.97 KiB) Viewed 5669 times

[EliWalton]

Wow -- lots to consider here....

First, if you use a 20A breaker, then you must have ALL the circuit wiring 12 ga -- NOT 14 ga. Also all receptacles on the circuit must be rated at 20A (one of slots looks like a "T" on its side) -- NOT 15A receptacles... otherwise, keep the 15A breaker...

Next, do NOT use that 10A cord reel for anything that takes more than 10A (e.g., Shopsmith)... regardless of what rewiring you do... there are still connections rated at 10A (and they look like junk to me). All extension cords to the Shopsmith must be rated at 15A or better... and keep the runs as short as possible...

I run my Mark V on a real 20A circuit -- it has great power and has never tripped a breaker... Trying to kludge together this cord reel and rewired extension cords will result in poor performance at best and a fire at worst...

Then the next thing someone will tell you that you need to upgrade to a PowerPro to "fix" your struggling Mark V... Just feed the Mark V with the voltage and amps is needs and it will do everything it was designed to do... Just sayin'

73 Ely

[EliWalton]

[...] reason being is electric current travels along the out side of a wire , a antenna ,,wire terminal ,,,,or metal object , by soldering the ends you bring all these lose ends back into one [...]

JMO

Reasonable people may differ on the pros/cons of soldering vs. crimping... but please take the "skin effect" out of the mix for our conversation about AC power... At 60Hz, AC is effectively DC -- there is no skin effect in home wiring -- it is all about the cross sectional area and material used for the conductors...

73 Ely

[Hobbyman2]

the code here is the wire gage cant be any smaller the the ground on the circut,, if there is a junction box feeding a circut then all wires are supposed to be the same size as the ground from the breaker box.

John I was taught Years ago the molecules in the copper wire become excited when a load is added to a circuit,, electricity will travel on the out side of the wire ,, the more current drawn the deeper the molecules in the wire become excited, after too much excitement the wire will become hot , the need for a larger wire or reduction on load .

if I recall a load of 80% of the breaker rating was max,,,, each receptacle was calculated for 1.5 amps like the light socket.

Plugs are also rated 15-20 amps etc,, the ul rating is ,,,should be stamped on the back of the socket. 20 amp 15 amp etc.

I have seen folks using 15 amp plugs on 12 wire 20 mp circuits in a garage when a 20 amp gfci would be a better selection. ,

You can buy a gfci breaker and protect every the entire circuit.

. =======80% of a 15 amp circuit 14 awg

maximum load = =======80% of a 20 amp circuit 12 awg

. =======80% of a 30 amp circuit 10 awg


One the 80% is reached the breaker should blow , they do make slow blow breakers and fuses, this will allow motor start up and are supposed to bow if the load does not drop back below 80%.

I could be wrong but this has been the norm here.


My concern about the posters trouble is we dont know the rating on the receptacle

[Hobbyman2]

[...] reason being is electric current travels along the out side of a wire , a antenna ,,wire terminal ,,,,or metal object , by soldering the ends you bring all these lose ends back into one [...]

JMO

Reasonable people may differ on the pros/cons of soldering vs. crimping... but please take the "skin effect" out of the mix for our conversation about AC power... At 60Hz, AC is effectively DC -- there is no skin effect in home wiring -- it is all about the cross sectional area and material used for the conductors...

73 Ely

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NOPE

Many people dont believe any thing that doesnt come with a link so I found you one.


So skin effect would be observed on cables with radius greater than 9.2 mm which means 18.4 mm diameter (3/4 inch) (or a 266 m² cross-section), which is very close to AWG(7\0), a gauge qualified to carry hundreds of amperes (while a domestic installation carries no more than 50 A). Since most cables for home are less than that, the skin effect is often and justifiably neglected in home electricity applications.

Also, the skin depth is the distance from the surface of the conductor to where the current density is damped to less than 1/e (36%) of its surface value. So in fact you would need even more diameter to observe the center of the cable having no current.

Regarding the choice between stranded and solid cables, solid cables are often preferred for home wiring for different reasons including cost, size, durability. Those have already been discussed in here :

https://electronics.stackexchange.com/q ... res/219122

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Like the site says,,,, it is neglected ,,,,,in house wire not that it doesnt exist ,, along with the magnetic resistance .

[reible]

https://en.wikipedia.org/wiki/Skin_effect

You want to know about it now read and enjoy. If you are in to math you can do some calculations if you like. If you don't understand it then that's fine too but we really don't need to know about it for this application.

Ed